tag:blogger.com,1999:blog-190336822024-03-14T17:08:34.002+00:00.. sounds off againSome say he always sounds "off" .. particularly playing bass.tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.comBlogger20125tag:blogger.com,1999:blog-19033682.post-90958155047682553812017-04-19T18:17:00.001+00:002017-04-19T18:22:36.037+00:00Amazon "Polly"<div dir="ltr" style="text-align: left;" trbidi="on">
The voices (and tech) used in Amazon Alexa, are available for anyone to play with, free of charge - search for Amazon Polly. Here's the voice of "Geraint" (Welsh English) reading Lewis Carroll:<br />
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<iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.blogger.com/video.g?token=AD6v5dwbN-jIX5u1eTeZckvRalecZJYzjzi_RQoe53bzzFH3YTW__NVs96bRIDaUZpKQ0moo3V3TY-KegK4' class='b-hbp-video b-uploaded' frameborder='0'></iframe></div>
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<a href="https://www.poetryfoundation.org/poems-and-poets/poems/detail/42916">https://www.poetryfoundation.org/poems-and-poets/poems/detail/42916</a><br />
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Try Polly here: <a href="https://eu-west-1.console.aws.amazon.com/polly/home/SynthesizeSpeech">https://eu-west-1.console.aws.amazon.com/polly/home/SynthesizeSpeech</a></div>
tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com0tag:blogger.com,1999:blog-19033682.post-19358801580436016482016-10-12T16:19:00.000+00:002016-10-12T16:19:05.966+00:00Shure wireless in-ear monitoring system<div dir="ltr" style="text-align: left;" trbidi="on">
A friend lent me their Shure PSM300 P3T in-ear monitoring system today. This is a top-of-the-line piece of kit for weekend-warrior type bands, costing over £600 for just one monitor mix.<br />
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http://www.shure.com/americas/products/personal-monitor-systems/psm-300-stereo-personal-monitor-system/p3t-half-rack-single-channel-wireless-transmitter<br />
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Turns out that the actual RF signal being transmitted is straightforward analog FM.<br />
A £10 USB TV stick and the free SDR# software http://www.rtl-sdr.com/rtl-sdr-quick-start-guide/ can decode the signal and play it out of the sound card output in stereo.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp1b9qilAG-Hk6ubng4AYti3LC258FNdaPvnvoILJ8UPpug-9GUguO_g7rzQgEz5WwXbrm8_dARMQshRqZUVv7kNgHnaWohisPliuQIURPVYNZd_M_XuCkyPmpJf0tEoBNd9bm/s1600/Screenshot+2016-10-12+16.51.32.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="322" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp1b9qilAG-Hk6ubng4AYti3LC258FNdaPvnvoILJ8UPpug-9GUguO_g7rzQgEz5WwXbrm8_dARMQshRqZUVv7kNgHnaWohisPliuQIURPVYNZd_M_XuCkyPmpJf0tEoBNd9bm/s400/Screenshot+2016-10-12+16.51.32.png" width="400" /></a></div>
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Shure mentions that there is some "24 bit digital" processing - what they call "Patented Shure Audio Reference Companding". The decoded PC signal does sound a bit swooshy compared to the actual Shure receiver unit, so that would suggest it is doing a bit of companding.<br />
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tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com0tag:blogger.com,1999:blog-19033682.post-39645384174829257252015-11-23T16:57:00.002+00:002016-01-21T18:13:29.726+00:00Differential line receiver for Behringer Ultranet<div dir="ltr" style="text-align: left;" trbidi="on">
Prototype receiver circuit based on AM26LV32 chip:<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJuuy5Z1u_qugXqtgXZ9ayNl1stgKFvQU6aAwVpBhhR2UWHME1It9hZ5A4wivtB4EjXZtxMWVX1UaYE-nQojPtynh83doh9Sbu0ShqH5tAGZ0KFchs3aFEzWGpelK8lVZAv3sr/s1600/IMG_0882.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJuuy5Z1u_qugXqtgXZ9ayNl1stgKFvQU6aAwVpBhhR2UWHME1It9hZ5A4wivtB4EjXZtxMWVX1UaYE-nQojPtynh83doh9Sbu0ShqH5tAGZ0KFchs3aFEzWGpelK8lVZAv3sr/s400/IMG_0882.JPG" width="300" /></a></div>
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The MagJack - a Bel Stewart SI-52008-F has datasheet here: http://www.farnell.com/datasheets/1731561.pdf</div>
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The IC cleans up the edges of the incoming signals.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjwPpzsZvAuPD5DqwAXWWnjeXFOu4JTl6Chyphenhyphenv5ErwnUGt7dG2AhAZIbJSWBA-7BD1RYyH0SGrqyKbw1FXpua6LDRqN81cy7UfQiYxlbAFZHAJNpfTM27qpW3q3R5LVJNImfb7n8/s1600/IMG_0883.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjwPpzsZvAuPD5DqwAXWWnjeXFOu4JTl6Chyphenhyphenv5ErwnUGt7dG2AhAZIbJSWBA-7BD1RYyH0SGrqyKbw1FXpua6LDRqN81cy7UfQiYxlbAFZHAJNpfTM27qpW3q3R5LVJNImfb7n8/s400/IMG_0883.JPG" width="400" /></a></div>
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With some level-shifting and AC coupling, the signals are OK to pass into an SPDIF receiver.<br />
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tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com5tag:blogger.com,1999:blog-19033682.post-77555451396514185902015-09-11T15:04:00.002+00:002015-09-11T15:11:01.161+00:00Audio test CD<div dir="ltr" style="text-align: left;" trbidi="on">
<div style="background-color: white; border: 0px; color: #373737; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 15px; line-height: 24.375px; margin-bottom: 1.625em; outline: 0px; padding: 0px; vertical-align: baseline;">
For repairing amplifiers.</div>
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Left and right channels have identical signals. The files were created using the excellent shareware <a href="http://www.goldwave.com/" style="border: 0px; color: #1982d1; font-family: inherit; font-style: inherit; font-weight: inherit; margin: 0px; outline: 0px; padding: 0px; text-decoration: none; vertical-align: baseline;">Goldwave audio editor</a>.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEirU8MQjCDY9h7TP9HsZ-jW5if74STAK_9addrgT0NUc5ir9hJ1EeE0Z5K4WWLgAnwobjyiAKFa5dotVSPe23WkaiPWHDpQryygAvrY-yN14vjSLFb6jJJaeLr1ELAR9rz_RriL/s1600/Goldwave-1000Hz-sine.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="498" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEirU8MQjCDY9h7TP9HsZ-jW5if74STAK_9addrgT0NUc5ir9hJ1EeE0Z5K4WWLgAnwobjyiAKFa5dotVSPe23WkaiPWHDpQryygAvrY-yN14vjSLFb6jJJaeLr1ELAR9rz_RriL/s640/Goldwave-1000Hz-sine.jpg" width="640" /></a></div>
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Track listing is as follows:</div>
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1) 1000Hz sine wave<br />
2) 1000Hz square wave<br />
3) 1000Hz triangle wave<br />
4) 440Hz sine wave<br />
5) 20Hz sine wave<br />
6) 20KHz sine wave</div>
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Each track is only 1 minute long, so use “Repeat” on your CD player to obtain a (nearly) continuous tone.</div>
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Don’t play this CD through your speakers, unless the volume is at minimum.</div>
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The audio tracks are recorded at 50% dynamic range, to avoid any clipping in the CD player itself (of course it should not do that, but my portable CD player used for testing is not perfect, maybe yours isn’t either).</div>
<div style="background-color: white; border: 0px; color: #373737; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 15px; line-height: 24.375px; margin-bottom: 1.625em; outline: 0px; padding: 0px; vertical-align: baseline;">
Download <a href="http://thetucks.com/wp-content/uploads/2015/07/Audio-Test-CD.zip" style="border: 0px; color: #1982d1; font-family: inherit; font-style: inherit; font-weight: inherit; margin: 0px; outline: 0px; padding: 0px; text-decoration: none; vertical-align: baseline;"> </a><a href="https://sites.google.com/site/tuck1s/audio-test-cd/Audio-Test-CD.zip" target="_blank">a ZIP of the .ISO and .CUE file</a> ready for burning with your favourite CD writing software.</div>
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Download a <a href="https://sites.google.com/site/tuck1s/audio-test-cd/Audio-Test-CD-wav-files.zip" target="_blank">ZIP of the original WAV files</a>.</div>
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tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com0tag:blogger.com,1999:blog-19033682.post-77269434601182537682015-09-07T22:26:00.002+00:002015-11-18T15:25:25.179+00:00XMOS StartKit - write performance of Sandisk memory card<div dir="ltr" style="text-align: left;" trbidi="on">
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Here's a graph showing the write performance to a Sandisk Class 10 memory card.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8Q0_Z_Uge4FQERsJNBH_CNxdTGtfbyge1g2U-pxd50worvKNmxykfCtqs4vj74T33c0k44W0fCNqCzA-mRpwGHuD6ahYNOOJWycChpQr34r1H02bhy547kiGBKCwvkMHqh79q/s1600/Screenshot+2015-09-07+23.24.55.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="389" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8Q0_Z_Uge4FQERsJNBH_CNxdTGtfbyge1g2U-pxd50worvKNmxykfCtqs4vj74T33c0k44W0fCNqCzA-mRpwGHuD6ahYNOOJWycChpQr34r1H02bhy547kiGBKCwvkMHqh79q/s640/Screenshot+2015-09-07+23.24.55.png" width="640" /></a></div>
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The reason for the sharp dips in performance, are that the FAT filing system has to go off and allocate a new cluster every N writes. For example 512 byte sectors, 32Kbyte clusters, means a new cluster is needed every 64 writes.</div>
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Another factor on the XMOS board is whether the code is running in 'debug' or 'release' mode. This can make around 2x difference.</div>
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I also found that the code published on https://github.com/xcore/sc_sdcard seems to not pay attention to setup and hold times, and appears to be leaving the clock line in a logic "1" state when in fact data gets clocked on a logic 0 -> 1 transition.</div>
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All this led me to branch the repo and produce my own version, here: https://github.com/tuck1s/sc_sdcard</div>
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The changes are too numerous to list here (see the github changelog) but with pre-allocation of a file with contiguous sectors, and a Sandisk Extreme Pro SDcard, there's enough performance to write around 3Mbytes/s to the card.</div>
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My experiments with the even smaller "PetitFAT" filing system were halted because it only reads/writes a sector at a time and that would not give enough performance.</div>
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Measuring 'where the time goes', I can see that the time taken to clock in a sector's worth is usually only a few hundred microseconds, whereas the card can then take several milliseconds to respond that it's done. This is highly variable and also highly dependent on the grade of the SD card.</div>
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tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com0tag:blogger.com,1999:blog-19033682.post-43555187459984259592015-08-31T23:08:00.000+00:002016-01-21T18:13:09.078+00:00XMOS StartKit - reading and writing to SD card<div dir="ltr" style="text-align: left;" trbidi="on">
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Being able to read/write information from an SD card is probably the easiest way to get large amounts of non-volatile storage into an embedded project.<br />
I'm using XMOS StartKit,, with the code <a href="https://github.com/xcore/sc_sdcard/blob/master/README.rst" target="_blank">from here</a><br />
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The card reader is a part from Wurth Elektronik, Farnell / CPC part number CN18143 available <a href="http://cpc.farnell.com/wurth-elektronik/693063010911/memory-socket-sd-card-push-pull/dp/CN18143?ost=CN18143" target="_blank">here</a>.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEifAbM7_nQyr_NIWBBLatcS8_q0Py2T1RQguVA7xPq-FEjHyMoSSY80xj8qQ9uSRDOg6MlvViKm8CtlphyphenhyphenbCGv6BwN8qj_9cb80XNf6UCXCuQNvZD01qNp8RvVAJ6gjs_lwgeA5/s1600/P1030990.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEifAbM7_nQyr_NIWBBLatcS8_q0Py2T1RQguVA7xPq-FEjHyMoSSY80xj8qQ9uSRDOg6MlvViKm8CtlphyphenhyphenbCGv6BwN8qj_9cb80XNf6UCXCuQNvZD01qNp8RvVAJ6gjs_lwgeA5/s640/P1030990.JPG" width="640" /></a></div>
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The data and clock lines have 120 ohm series resistors, as this can help to absorb transmission-line reflections on the connecting wires (even though they are fairly short).</div>
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In addition, pins 2 and 7 have 10K ohm pull up resistors.</div>
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Pins on an SD card are numbered from 9 (the chamfered end), then 1 to 8. This is because very early cards, like the one shown above, have no pin 9.</div>
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SD cards run from 3.3v, so this can be provided directly from the StartKit board.</div>
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The XMOS code supports both 1-bit (SPI mode) and 4-bit data access mode. Initially the code is set to use 1-bit SPI mode.</div>
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As well as GND and 3.3V, SPI mode only requires pins:</div>
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1 CS<br />
2 MOSI<br />
5 SCLK<br />
7 MISO</div>
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These are connected up and monitored on the scope.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiBRF66ewmUht-KdM1Y_3_vJ976xfoOL1wE9H3LTLQCCmJtXgiHN-gmWhAE7Q3KD-AGoj0wWiwAJ8dfLJaB2c0TanmELaEoeBKPYMDZ7MuictYYYyn500QvIwD9o94Oo3ekBHkV/s1600/P1030992.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiBRF66ewmUht-KdM1Y_3_vJ976xfoOL1wE9H3LTLQCCmJtXgiHN-gmWhAE7Q3KD-AGoj0wWiwAJ8dfLJaB2c0TanmELaEoeBKPYMDZ7MuictYYYyn500QvIwD9o94Oo3ekBHkV/s640/P1030992.JPG" width="640" /></a></div>
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The signal quality looks OK.</div>
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The very old 16Mbyte card that I started with, would not read/write (it gave reason code=3).</div>
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A newer 16GB card read/wrote OK, as follows:</div>
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<pre class="brush: php">15026112 KB total drive space.
15748096 KB available.
Deleting file Data.bin if existing...done.
Creating a new file Data.bin...done.
Writing data to the file...20480 bytes written. Write rate: 215KBytes/Sec
Closing the file...done.
Opening an existing file: Data.bin...done.
Reading file content...20480 bytes read. Read rate: 275KBytes/Sec
Closing the file...done.
Open root directory.
Directory listing...
<dir> DCIM
<dir> MISC
<dir> PRIVATE
4096 ~1.TRA
20480 DATA.BIN
<dir> TRASHE~1
<dir> SYSTEM~1
Test completed.
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The file SDCardHostSPI.xc contains the XMOS port mappings for these lines, as follows. I've used these unchanged in this test.</div>
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<pre class="brush: php">static SDHostInterface SDif[] = // LIST HERE THE PORTS USED FOR THE INTERFACES
// cs, sclk, Mosi, miso
{XS1_CLKBLK_1, XS1_CLKBLK_2, XS1_PORT_1O, XS1_PORT_1M, XS1_PORT_1N, XS1_PORT_1P, 0, 0}; // resources used for interface #0</pre>
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The ports map onto StartKit pins as follows:</div>
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SD card 1 CS = XMOS J7 pin 21 = Port 1O</div>
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SD card 2 MOSI = XMOS J7 pin 17 = Port 1N</div>
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SD card 5 SCLK = XMOS J7 pin 15 = Port 1M</div>
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SD card 7 MISO = XMOS J7 pin 23 = Port 1P
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tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com2tag:blogger.com,1999:blog-19033682.post-82489271559603689082015-08-24T10:58:00.004+00:002015-11-18T15:20:42.167+00:00Rigol DS1054Z digital storage scope - decoding I2S signals<div dir="ltr" style="text-align: left;" trbidi="on">
I recently got one of these <a href="http://www.rigol-uk.co.uk/Rigol-DS1074Z-Digital-Oscilloscope-p/ds1074z.htm#.VdrwaNNVhBc" target="_blank">great little digital scopes</a>. It has a few serial bus decoding packages (on a try-before-buy basis). You get 36 hours to play with them. Unfortunately they don't include I2S bus decoding. I2S is a <a href="https://en.wikipedia.org/wiki/I%C2%B2S" target="_blank">bus standard</a> commonly used for transferring digital audio around, for example between ADCs and DACs.<br />
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No matter! You can capture and export full-resolution traces of signals via a USB memory stick. This seems to work best if the stick is FAT formatted rather than FAT32. The file format is .CSV which is great for importing into Excel and viewing. You can then use Excel's charting function to provide a decode of your signals with much greater time-resolution than you can see on the scope's display itself (which is still pretty good). For example<br />
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<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgbnYWysJ9qY1HCGnUecXHDc68rmG55cyB4TGR-X4s0IWo2GHwVhOCkxbrzzg9T4vGznVZPoPqhm7xEra_3AsPslKJnGo71SqWtlhLumookwH7pDlDma38yMd5MfFF46jjH6k7D/s1600/Screenshot+2015-08-24+11.52.02.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="427" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgbnYWysJ9qY1HCGnUecXHDc68rmG55cyB4TGR-X4s0IWo2GHwVhOCkxbrzzg9T4vGznVZPoPqhm7xEra_3AsPslKJnGo71SqWtlhLumookwH7pDlDma38yMd5MfFF46jjH6k7D/s640/Screenshot+2015-08-24+11.52.02.png" width="640" /></a></div>
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You can also parse the .CSV file and decode signals quite easily using scripting languages such as PHP, giving outputs in binary, hex or whatever you like - e.g.<br />
<br />
<pre class="brush: php">Using logic threshold of 1.900000 volts
00000000 00001000 00000000 001 Bits:27 Hex: 00004001 #0:64
540 LRCLK edge 1: 00000000 00000000 00110000 00000001 Bits:32 Hex: 00003001 #1:48
1191 LRCLK edge 2: 00000000 00000000 00010000 00000001 Bits:32 Hex: 00001001 #2:16
1842 LRCLK edge 3: 00000000 00000000 01010000 00000001 Bits:32 Hex: 00005001 #3:80
2494 LRCLK edge 4: 11111010 10000011 11110000 00000001 Bits:32 Hex: fa83f001 #4:-359440
3145 LRCLK edge 5: 00000000 00000000 00100000 00000001 Bits:32 Hex: 00002001 #5:32
3796 LRCLK edge 6: 00000000 00000000 00010000 00000001 Bits:32 Hex: 00001001 #6:16
4447 LRCLK edge 7: 00000000 00000000 00010000 00000001 Bits:32 Hex: 00001001 #7:16
5098 LRCLK edge 8: 11111111 11111111 10100000 00000001 Bits:32 Hex: ffffa001 #0:-96
5749 LRCLK edge 9: 00000000 00000000 00010000 00000001 Bits:32 Hex: 00001001 #1:16
6400 LRCLK edge 10: 11111111 11111111 11000000 00000001 Bits:32 Hex: ffffc001 #2:-64
</pre>
Here's the code - updated to read the signals on the correct edge
<br />
<pre class="brush: php"><?php
// Decode I2S data captured in CSV file from Rigol DS1054Z scope
// Assumptions: First two rows in the file are header lines - skip these.
//
// Channels are arranged as : CH1 = BCLK, CH2 = LRCLK, CH3 = DOUT, CH4 = scopetrig
// Command line parameters: <inputfile> <voltage threshold>
// threshold of 1.8 or 1.9 volts seems to be reliable with 3.3v logic.
//
// Fixed to toggle in data on rising edges of BCLK
if($argv[1] == "") {
exit("Usage: ".$argv[0]." input_file [voltage_threshold]\n");
}
// Get parameters
$fp = fopen($argv[1], "r");
if($argv[2] == "") {
$threshold = 1.8;
}
else {
$threshold = (float)$argv[2]; //Volts
}
if(is_numeric($threshold)) {
print("Using logic threshold of ".sprintf("%f", $threshold)." volts\n");
}
else {
exit("voltage threshold must be a numeric value");
}
// Skip the two expected header lines
$ln = fgetcsv($fp);
$ln = fgetcsv($fp);
$i=1;
// Get the first line of real data in
$ln = fgetcsv($fp);
$bclk = $ln[0];
$lrclk = $ln[1];
$dout = $ln[2];
// Set up initial trigger conditions
$bclkTrig = $bclk;
$lrclkTrig = $lrclk;
//Count edges as they happen
$bclkEdgeCount = 0;
$lrclkEdgeCount = 0;
$doneLSB = false;
// Collect bits into this shift register
$bitcount = 0;
$doutShiftReg = 0;
while(!feof($fp)) {
$i=$i+1;
$ln = fgetcsv($fp);
$bclk = $ln[0];
$lrclk = $ln[1];
$dout = $ln[2];
// Check for a RISING edge in BCLK
if(($bclkTrig <$threshold) && ($bclk >= $threshold) ) {
$bclkEdgeCount++;
// Check if the LRCLK line has changed state since the last edge
if( ($lrclkTrig >$threshold) <> ($lrclk >$threshold)) {
// Dump out hex value accumulated so far, the count of bits in this sample, and decimal equivalent
$hexnum = sprintf("%08x", $doutShiftReg);
// Handle 2-s complement sign conversion for the 24-bit audio
$signedSample = $doutShiftReg >> 8;
if($signedSample >= 2**23 -1) {
$signedSample = $signedSample - (2**24);
}
echo " Bits:".$bitcount." Hex: ".$hexnum." #".($lrclkEdgeCount %8).":".$signedSample;
$lrclkEdgeCount++;
echo "\n".sprintf("%8d",$i)." LRCLK edge ".sprintf("%4d",$lrclkEdgeCount).": ";
$lrclkTrig = $lrclk;
// Start accumulating bits into the shift register
$bitcount = 0;
$doutShiftReg = 0;
}
// output raw data, and accumulate it into shift register
if($dout > $threshold) $doutBit = 1; else $doutBit = 0;
echo $doutBit;
$bitcount++;
if($bitcount %8 == 0) echo " "; // pretty-print spacing
$doutShiftReg = ($doutShiftReg <<1) + $doutBit;
}
// this is the new value we'll compare against
$bclkTrig = $bclk;
}
echo "\n";
?>
</pre>
Using the program, it's possible to capture I2S signals and decode them as follows. This is data from a Behringer P16I device, through a Wolfson WM8804 evaulation board:<pre class="brush: php">
Using logic threshold of 1.900000 volts
0000001 Bits:7 Hex: 00000001 #0:0
132 LRCLK edge 1: 11111111 11111111 11000000 00000001 Bits:32 Hex: ffffc001 #1:-64
783 LRCLK edge 2: 11111111 11111111 10100000 00000001 Bits:32 Hex: ffffa001 #2:-96
1434 LRCLK edge 3: 11111111 11111111 01100000 00000001 Bits:32 Hex: ffff6001 #3:-160
2086 LRCLK edge 4: 11111111 11111111 01110000 00000001 Bits:32 Hex: ffff7001 #4:-144
2737 LRCLK edge 5: 00000000 00000000 00100000 00000001 Bits:32 Hex: 00002001 #5:32
3388 LRCLK edge 6: 11111111 11111111 11010000 00000001 Bits:32 Hex: ffffd001 #6:-48
4039 LRCLK edge 7: 11111111 11111111 10010000 00000001 Bits:32 Hex: ffff9001 #7:-112
4690 LRCLK edge 8: 00000000 00000000 01100000 00000001 Bits:32 Hex: 00006001 #0:96
5341 LRCLK edge 9: 11111111 11111110 11110000 00000001 Bits:32 Hex: fffef001 #1:-272
5992 LRCLK edge 10: 11111111 11111111 10110000 00000001 Bits:32 Hex: ffffb001 #2:-80
6643 LRCLK edge 11: 00000000 00000000 01110000 00000001 Bits:32 Hex: 00007001 #3:112
7294 LRCLK edge 12: 00000000 00000000 11010000 00000001 Bits:32 Hex: 0000d001 #4:208
7945 LRCLK edge 13: 00000000 00000000 01100000 00000001 Bits:32 Hex: 00006001 #5:96
8596 LRCLK edge 14: 00000000 00000000 00010000 00000001 Bits:32 Hex: 00001001 #6:16
9247 LRCLK edge 15: 00000000 00000000 10010000 00000001 Bits:32 Hex: 00009001 #7:144
9898 LRCLK edge 16: 11111111 11111111 01010000 00000001 Bits:32 Hex: ffff5001 #0:-176
10549 LRCLK edge 17: 11111111 11111111 10110000 00000001 Bits:32 Hex: ffffb001 #1:-80
11200 LRCLK edge 18: 00000000 00000000 01000000 00000001 Bits:32 Hex: 00004001 #2:64
11851 LRCLK edge 19: 00000000 00000000 01100000 00000001 Bits:32 Hex: 00006001 #3:96
12502 LRCLK edge 20: 11111111 11111111 10110000 00000001 Bits:32 Hex: ffffb001 #4:-80
13153 LRCLK edge 21: 00000000 00000000 10100000 00000001 Bits:32 Hex: 0000a001 #5:160
13804 LRCLK edge 22: 00000000 00000000 00010000 00000001 Bits:32 Hex: 00001001 #6:16
14455 LRCLK edge 23: 11111111 11111111 10000000 00000001 Bits:32 Hex: ffff8001 #7:-128
15106 LRCLK edge 24: 00000000 00000000 10000000 00000001 Bits:32 Hex: 00008001 #0:128
15758 LRCLK edge 25: 11111111 11111111 10010000 00000001 Bits:32 Hex: ffff9001 #1:-112
16409 LRCLK edge 26: 11111111 11111111 10100000 00000001 Bits:32 Hex: ffffa001 #2:-96
17060 LRCLK edge 27: 00000000 00000000 00000000 00000001 Bits:32 Hex: 00000001 #3:0
17711 LRCLK edge 28: 00000000 00000000 00000000 00000001 Bits:32 Hex: 00000001 #4:0
18362 LRCLK edge 29: 00000000 00000000 11100000 00000001 Bits:32 Hex: 0000e001 #5:224
19013 LRCLK edge 30: 00000000 00000000 10000000 00000001 Bits:32 Hex: 00008001 #6:128
19664 LRCLK edge 31: 00000000 00000000 01010000 00000001 Bits:32 Hex: 00005001 #7:80
20315 LRCLK edge 32: 00000000 00000000 10100000 00000001 Bits:32 Hex: 0000a001 #0:160
20966 LRCLK edge 33: 11111111 11111111 11000000 00000001 Bits:32 Hex: ffffc001 #1:-64
21617 LRCLK edge 34: 11111111 11111110 11110000 00000001 Bits:32 Hex: fffef001 #2:-272
22268 LRCLK edge 35: 11111111 11111111 10100000 00000001 Bits:32 Hex: ffffa001 #3:-96
22919 LRCLK edge 36: 00000000 00000000 00110000 00000001 Bits:32 Hex: 00003001 #4:48
23570 LRCLK edge 37: 00000000 00000000 01000000 00000001 Bits:32 Hex: 00004001 #5:64
24221 LRCLK edge 38: 11111111 11111111 11100000 00000001 Bits:32 Hex: ffffe001 #6:-32
24872 LRCLK edge 39: 11111111 11111111 11100000 00000001 Bits:32 Hex: ffffe001 #7:-32
25523 LRCLK edge 40: 11111111 11111111 11110000 00000001 Bits:32 Hex: fffff001 #0:-16
26174 LRCLK edge 41: 00000000 00000000 10010000 00000001 Bits:32 Hex: 00009001 #1:144
26825 LRCLK edge 42: 00000000 00000000 01010000 00000001 Bits:32 Hex: 00005001 #2:80
27476 LRCLK edge 43: 11111111 11111111 10000000 00000001 Bits:32 Hex: ffff8001 #3:-128
28127 LRCLK edge 44: 11111111 11111111 01110000 00000001 Bits:32 Hex: ffff7001 #4:-144
28778 LRCLK edge 45: 00000000 00000001 00000000 00000001 Bits:32 Hex: 00010001 #5:256
29429 LRCLK edge 46: 11111111 11111111 11110000 00000001 Bits:32 Hex: fffff001 #6:-16
30080 LRCLK edge 47: 00000000 00000000 01000000 00000001 Bits:32 Hex: 00004001 #7:64
30732 LRCLK edge 48: 11111111 11111111 00110000 00000001 Bits:32 Hex: ffff3001 #0:-208
31383 LRCLK edge 49: 00000000 00000000 00010000 00000001 Bits:32 Hex: 00001001 #1:16
32034 LRCLK edge 50: 00000000 00000000 01000000 00000001 Bits:32 Hex: 00004001 #2:64
32685 LRCLK edge 51: 00000000 00000000 01110000 00000001 Bits:32 Hex: 00007001 #3:112
33336 LRCLK edge 52: 11111111 11111111 10010000 00000001 Bits:32 Hex: ffff9001 #4:-112
33987 LRCLK edge 53: 11111111 11111111 00100000 00000001 Bits:32 Hex: ffff2001 #5:-224
34638 LRCLK edge 54: 11111111 11111111 01100000 00000001 Bits:32 Hex: ffff6001 #6:-160
35289 LRCLK edge 55: 11111111 11111111 01100000 00000001 Bits:32 Hex: ffff6001 #7:-160
35940 LRCLK edge 56: 00000000 00000000 00100000 00000001 Bits:32 Hex: 00002001 #0:32
36591 LRCLK edge 57: 00000000 00000000 01000000 00000001 Bits:32 Hex: 00004001 #1:64
37242 LRCLK edge 58: 00000000 00000000 00000000 00000001 Bits:32 Hex: 00000001 #2:0
37893 LRCLK edge 59: 00000000 00000000 01010000 00000001 Bits:32 Hex: 00005001 #3:80
38544 LRCLK edge 60: 00000000 00000001 00010000 00000001 Bits:32 Hex: 00011001 #4:272
39195 LRCLK edge 61: 11111111 11111111 11100000 00000001 Bits:32 Hex: ffffe001 #5:-32
39846 LRCLK edge 62: 11111111 11111111 11100000 00000001 Bits:32 Hex: ffffe001 #6:-32
40497 LRCLK edge 63: 00000000 00000000 01110000 00000001 Bits:32 Hex: 00007001 #7:112
41148 LRCLK edge 64: 11111111 11111111 11110000 00000001 Bits:32 Hex: fffff001 #0:-16
41799 LRCLK edge 65: 00000000 00000000 00000000 00000001 Bits:32 Hex: 00000001 #1:0
42450 LRCLK edge 66: 11111111 11111111 10000000 00000001 Bits:32 Hex: ffff8001 #2:-128
43101 LRCLK edge 67: 11111111 11111110 11100000 00000001 Bits:32 Hex: fffee001 #3:-288
43753 LRCLK edge 68: 11111111 11111111 10010000 00000001 Bits:32 Hex: ffff9001 #4:-112
44403 LRCLK edge 69: 00000000 00000000 10000000 00000001 Bits:32 Hex: 00008001 #5:128
45054 LRCLK edge 70: 00000000 00000000 10000000 00000001 Bits:32 Hex: 00008001 #6:128
45706 LRCLK edge 71: 00000000 00000000 10100000 00000001 Bits:32 Hex: 0000a001 #7:160
46357 LRCLK edge 72: 11111111 11111111 01100000 00000001 Bits:32 Hex: ffff6001 #0:-160
47008 LRCLK edge 73: 11111111 11111111 10000000 00000001 Bits:32 Hex: ffff8001 #1:-128
47659 LRCLK edge 74: 11111111 11111111 11010000 00000001 Bits:32 Hex: ffffd001 #2:-48
48310 LRCLK edge 75: 11111111 11111111 01010000 00000001 Bits:32 Hex: ffff5001 #3:-176
48961 LRCLK edge 76: 00000000 00000000 01000000 00000001 Bits:32 Hex: 00004001 #4:64
49612 LRCLK edge 77: 00000000 00000000 01110000 00000001 Bits:32 Hex: 00007001 #5:112
50263 LRCLK edge 78: 11111111 11111111 01110000 00000001 Bits:32 Hex: ffff7001 #6:-144
50914 LRCLK edge 79: 00000000 00000000 11110000 00000001 Bits:32 Hex: 0000f001 #7:240
51565 LRCLK edge 80: 00000000 00000000 01100000 00000001 Bits:32 Hex: 00006001 #0:96
52216 LRCLK edge 81: 11111111 11111110 11110000 00000001 Bits:32 Hex: fffef001 #1:-272
52867 LRCLK edge 82: 11111111 11111111 10000000 00000001 Bits:32 Hex: ffff8001 #2:-128
53518 LRCLK edge 83: 00000000 00000000 00010000 00000001 Bits:32 Hex: 00001001 #3:16
54169 LRCLK edge 84: 00000000 00000000 10010000 00000001 Bits:32 Hex: 00009001 #4:144
54820 LRCLK edge 85: 00000000 00000000 10110000 00000001 Bits:32 Hex: 0000b001 #5:176
55471 LRCLK edge 86: 00000000 00000000 10010000 00000001 Bits:32 Hex: 00009001 #6:144
56122 LRCLK edge 87: 11111111 11111111 10100000 00000001 Bits:32 Hex: ffffa001 #7:-96
56773 LRCLK edge 88: 00000000 00000000 00100000 00000001 Bits:32 Hex: 00002001 #0:32
57424 LRCLK edge 89: 11111111 11111111 11110000 00000001 Bits:32 Hex: fffff001 #1:-16
58075 LRCLK edge 90: 00000000 00000000 10000000 00000001 Bits:32 Hex: 00008001 #2:128
58727 LRCLK edge 91: 00000000 00000000 01110000 00000001 Bits:32 Hex: 00007001 #3:112
59378 LRCLK edge 92: 00000000 00000000 10110000 00000001 Bits:32 Hex: 0000b001 #4:176
60029 LRCLK edge 93: 00000000 00000000 00110000 00000001 Bits:32 Hex: 00003001 #5:48
60680 LRCLK edge 94: 00000000 00000000 10110000 00000001 Bits:32 Hex: 0000b001 #6:176
61331 LRCLK edge 95: 11111111 11111111 01010000 00000001 Bits:32 Hex: ffff5001 #7:-176
61982 LRCLK edge 96: 11111111 11111111 11100000 00000001 Bits:32 Hex: ffffe001 #0:-32
62633 LRCLK edge 97: 11111111 11111111 10100000 00000001 Bits:32 Hex: ffffa001 #1:-96
63284 LRCLK edge 98: 11111111 11111111 11010000 00000001 Bits:32 Hex: ffffd001 #2:-48
63935 LRCLK edge 99: 11111111 11111111 11110000 00000001 Bits:32 Hex: fffff001 #3:-16
64586 LRCLK edge 100: 11111111 11111111 10100000 00000001 Bits:32 Hex: ffffa001 #4:-96
65237 LRCLK edge 101: 00000000 00000000 01100000 00000001 Bits:32 Hex: 00006001 #5:96
65888 LRCLK edge 102: 11111111 11111111 11100000 00000001 Bits:32 Hex: ffffe001 #6:-32
66539 LRCLK edge 103: 11111111 11111111 11110000 00000001 Bits:32 Hex: fffff001 #7:-16
67190 LRCLK edge 104: 11111111 11111111 10010000 00000001 Bits:32 Hex: ffff9001 #0:-112
67841 LRCLK edge 105: 11111111 11111111 11110000 00000001 Bits:32 Hex: fffff001 #1:-16
68492 LRCLK edge 106: 11111111 11111111 01110000 00000001 Bits:32 Hex: ffff7001 #2:-144
69143 LRCLK edge 107: 00000000 00000000 10010000 00000001 Bits:32 Hex: 00009001 #3:144
69794 LRCLK edge 108: 11111111 11111111 11100000 00000001 Bits:32 Hex: ffffe001 #4:-32
70445 LRCLK edge 109: 11111111 11111111 10010000 00000001 Bits:32 Hex: ffff9001 #5:-112
71096 LRCLK edge 110: 00000000 00000000 00000000 00000001 Bits:32 Hex: 00000001 #6:0
71747 LRCLK edge 111: 00000000 00000000 10110000 00000001 Bits:32 Hex: 0000b001 #7:176
72399 LRCLK edge 112: 00000000 00000000 11010000 00000001 Bits:32 Hex: 0000d001 #0:208
73050 LRCLK edge 113: 11111111 11111111 11110000 00000001 Bits:32 Hex: fffff001 #1:-16
73701 LRCLK edge 114: 11111111 11111111 01110000 00000001 Bits:32 Hex: ffff7001 #2:-144
74352 LRCLK edge 115: 11111111 11111111 01100000 00000001 Bits:32 Hex: ffff6001 #3:-160
75003 LRCLK edge 116: 11111111 11111111 11110000 00000001 Bits:32 Hex: fffff001 #4:-16
75654 LRCLK edge 117: 11111111 11111111 10110000 00000001 Bits:32 Hex: ffffb001 #5:-80
76305 LRCLK edge 118: 11111111 11111111 10110000 00000001 Bits:32 Hex: ffffb001 #6:-80
76956 LRCLK edge 119: 11111111 11111111 10110000 00000001 Bits:32 Hex: ffffb001 #7:-80
77607 LRCLK edge 120: 11111111 11111111 11010000 00000001 Bits:32 Hex: ffffd001 #0:-48
78258 LRCLK edge 121: 11111111 11111111 11010000 00000001 Bits:32 Hex: ffffd001 #1:-48
78909 LRCLK edge 122: 11111111 11111111 11010000 00000001 Bits:32 Hex: ffffd001 #2:-48
79560 LRCLK edge 123: 11111111 11111111 01110000 00000001 Bits:32 Hex: ffff7001 #3:-144
80211 LRCLK edge 124: 11111111 11111111 01110000 00000001 Bits:32 Hex: ffff7001 #4:-144
80862 LRCLK edge 125: 11111111 11111111 11100000 00000001 Bits:32 Hex: ffffe001 #5:-32
81513 LRCLK edge 126: 11111111 11111111 11010000 00000001 Bits:32 Hex: ffffd001 #6:-48
82164 LRCLK edge 127: 11111111 11111111 10100000 00000001 Bits:32 Hex: ffffa001 #7:-96
82815 LRCLK edge 128: 00000000 00000000 01100000 00000001 Bits:32 Hex: 00006001 #0:96
83466 LRCLK edge 129: 00000000 00000000 00100000 00000001 Bits:32 Hex: 00002001 #1:32
84117 LRCLK edge 130: 00000000 00000000 10000000 00000001 Bits:32 Hex: 00008001 #2:128
84768 LRCLK edge 131: 00000000 00000000 11110000 00000001 Bits:32 Hex: 0000f001 #3:240
85420 LRCLK edge 132: 00000000 00000000 01010000 00000001 Bits:32 Hex: 00005001 #4:80
86071 LRCLK edge 133: 00000000 00000000 00110000 00000001 Bits:32 Hex: 00003001 #5:48
86722 LRCLK edge 134: 11111111 11111111 11000000 00000001 Bits:32 Hex: ffffc001 #6:-64
87373 LRCLK edge 135: 11111111 11111111 10010000 00000001 Bits:32 Hex: ffff9001 #7:-112
88024 LRCLK edge 136: 11111111 11111111 11110000 00000001 Bits:32 Hex: fffff001 #0:-16
88675 LRCLK edge 137: 11111111 11111111 10100000 00000001 Bits:32 Hex: ffffa001 #1:-96
89326 LRCLK edge 138: 00000000 00000001 00000000 00000001 Bits:32 Hex: 00010001 #2:256
89977 LRCLK edge 139: 11111111 11111111 10010000 00000001 Bits:32 Hex: ffff9001 #3:-112
90628 LRCLK edge 140: 00000000 00000000 10000000 00000001 Bits:32 Hex: 00008001 #4:128
91279 LRCLK edge 141: 00000000 00000000 00010000 00000001 Bits:32 Hex: 00001001 #5:16
91930 LRCLK edge 142: 00000000 00000000 11000000 00000001 Bits:32 Hex: 0000c001 #6:192
92581 LRCLK edge 143: 00000000 00000000 00010000 00000001 Bits:32 Hex: 00001001 #7:16
93232 LRCLK edge 144: 11111111 11111111 01000000 00000001 Bits:32 Hex: ffff4001 #0:-192
93883 LRCLK edge 145: 00000000 00000000 11000000 00000001 Bits:32 Hex: 0000c001 #1:192
94534 LRCLK edge 146: 00000000 00000000 00100000 00000001 Bits:32 Hex: 00002001 #2:32
95185 LRCLK edge 147: 00000000 00000000 01000000 00000001 Bits:32 Hex: 00004001 #3:64
95836 LRCLK edge 148: 11111111 11111111 10100000 00000001 Bits:32 Hex: ffffa001 #4:-96
96487 LRCLK edge 149: 11111111 11111111 10110000 00000001 Bits:32 Hex: ffffb001 #5:-80
97138 LRCLK edge 150: 00000000 00000000 01110000 00000001 Bits:32 Hex: 00007001 #6:112
97789 LRCLK edge 151: 11111111 11111111 10110000 00000001 Bits:32 Hex: ffffb001 #7:-80
98440 LRCLK edge 152: 00000000 00000000 00110000 00001001 Bits:32 Hex: 00003009 #0:48
99091 LRCLK edge 153: 11111111 11111111 10100000 00001001 Bits:32 Hex: ffffa009 #1:-96
99742 LRCLK edge 154: 11111111 11111111 11010000 00000001 Bits:32 Hex: ffffd001 #2:-48
100394 LRCLK edge 155: 00000000 00000000 10100000 00000001 Bits:32 Hex: 0000a001 #3:160
101045 LRCLK edge 156: 00000000 00000000 00110000 00000001 Bits:32 Hex: 00003001 #4:48
101696 LRCLK edge 157: 00000000 00000000 10110000 00000001 Bits:32 Hex: 0000b001 #5:176
102347 LRCLK edge 158: 00000000 00000000 11100000 00000001 Bits:32 Hex: 0000e001 #6:224
102998 LRCLK edge 159: 00000000 00000000 11010000 00000001 Bits:32 Hex: 0000d001 #7:208
103649 LRCLK edge 160: 00000000 00000000 10100000 00000001 Bits:32 Hex: 0000a001 #0:160
104300 LRCLK edge 161: 00000000 00000000 01110000 00000001 Bits:32 Hex: 00007001 #1:112
104951 LRCLK edge 162: 11111111 11111111 10010000 00000001 Bits:32 Hex: ffff9001 #2:-112
105602 LRCLK edge 163: 11111111 11111110 11000000 00000001 Bits:32 Hex: fffec001 #3:-320
106253 LRCLK edge 164: 00000000 00000000 00100000 00000001 Bits:32 Hex: 00002001 #4:32
106904 LRCLK edge 165: 00000000 00000000 01010000 00000001 Bits:32 Hex: 00005001 #5:80
107555 LRCLK edge 166: 00000000 00000000 01010000 00000001 Bits:32 Hex: 00005001 #6:80
108206 LRCLK edge 167: 00000000 00000000 00010000 00000001 Bits:32 Hex: 00001001 #7:16
108857 LRCLK edge 168: 11111111 11111111 11100000 00000001 Bits:32 Hex: ffffe001 #0:-32
109508 LRCLK edge 169: 00000000 00000000 01010000 00000001 Bits:32 Hex: 00005001 #1:80
110159 LRCLK edge 170: 11111111 11111111 01100000 00000001 Bits:32 Hex: ffff6001 #2:-160
110810 LRCLK edge 171: 11111111 11111111 11100000 00000001 Bits:32 Hex: ffffe001 #3:-32
111461 LRCLK edge 172: 11111111 11111111 11010000 00000001 Bits:32 Hex: ffffd001 #4:-48
112112 LRCLK edge 173: 00000000 00000000 00110000 00000001 Bits:32 Hex: 00003001 #5:48
112764 LRCLK edge 174: 00000000 00000000 10110000 00000001 Bits:32 Hex: 0000b001 #6:176
113414 LRCLK edge 175: 00000000 00000000 10100000 00000001 Bits:32 Hex: 0000a001 #7:160
114065 LRCLK edge 176: 11111111 11111111 10100000 00000001 Bits:32 Hex: ffffa001 #0:-96
114717 LRCLK edge 177: 11111111 11111111 10000000 00000001 Bits:32 Hex: ffff8001 #1:-128
115368 LRCLK edge 178: 11111111 11111111 11100000 00000001 Bits:32 Hex: ffffe001 #2:-32
116019 LRCLK edge 179: 00000000 00000000 01110000 00000001 Bits:32 Hex: 00007001 #3:112
116670 LRCLK edge 180: 00000000 00000000 01010000 00000001 Bits:32 Hex: 00005001 #4:80
117321 LRCLK edge 181: 11111111 11111111 10110000 00000001 Bits:32 Hex: ffffb001 #5:-80
117972 LRCLK edge 182: 11111111 11111111 01100000 00000001 Bits:32 Hex: ffff6001 #6:-160
118623 LRCLK edge 183: 11111111 11111111 10110000 00000001 Bits:32 Hex: ffffb001 #7:-80
119274 LRCLK edge 184: 00000000 00000000 01100000 00000001 Bits:32 Hex: 00006001 #0:96
119925 LRCLK edge 185: 11111111 11111111 11110000 00000001 Bits:32 Hex: fffff001 #1:-16
120576 LRCLK edge 186: 00000000 00000000 10010000 00000001 Bits:32 Hex: 00009001 #2:144
121227 LRCLK edge 187: 11111111 11111111 11110000 00000001 Bits:32 Hex: fffff001 #3:-16
121878 LRCLK edge 188: 11111111 11111111 11110000 00000001 Bits:32 Hex: fffff001 #4:-16
122529 LRCLK edge 189: 11111111 11111111 10100000 00000001 Bits:32 Hex: ffffa001 #5:-96
123180 LRCLK edge 190: 00000000 00000000 00010000 00000001 Bits:32 Hex: 00001001 #6:16
123831 LRCLK edge 191: 00000000 00000000 01110000 00000001 Bits:32 Hex: 00007001 #7:112
124482 LRCLK edge 192: 11111111 11111111 01000000 00000001 Bits:32 Hex: ffff4001 #0:-192
125133 LRCLK edge 193: 11111111 11111111 11100000 00000001 Bits:32 Hex: ffffe001 #1:-32
125784 LRCLK edge 194: 11111111 11111111 01100000 00000001 Bits:32 Hex: ffff6001 #2:-160
126435 LRCLK edge 195: 00000000 00000000 11110000 00000001 Bits:32 Hex: 0000f001 #3:240
127086 LRCLK edge 196: 00000000 00000001 00010000 00000001 Bits:32 Hex: 00011001 #4:272
127737 LRCLK edge 197: 11111111 11111111 00110000 00000001 Bits:32 Hex: ffff3001 #5:-208
128389 LRCLK edge 198: 00000000 00000000 10010000 00000001 Bits:32 Hex: 00009001 #6:144
129040 LRCLK edge 199: 11111111 11111111 10100000 00000001 Bits:32 Hex: ffffa001 #7:-96
129691 LRCLK edge 200: 00000000 00000000 01000000 00000001 Bits:32 Hex: 00004001 #0:64
130342 LRCLK edge 201: 11111111 11111111 10110000 00000001 Bits:32 Hex: ffffb001 #1:-80
130993 LRCLK edge 202: 00000000 00000000 00010000 00000001 Bits:32 Hex: 00001001 #2:16
131644 LRCLK edge 203: 00000000 00000000 10010000 00000001 Bits:32 Hex: 00009001 #3:144
132295 LRCLK edge 204: 11111111 11111111 11010000 00000001 Bits:32 Hex: ffffd001 #4:-48
132946 LRCLK edge 205: 00000000 00000000 00010000 00000001 Bits:32 Hex: 00001001 #5:16
133597 LRCLK edge 206: 11111111 11111111 01000000 00000001 Bits:32 Hex: ffff4001 #6:-192
134248 LRCLK edge 207: 00000000 00000000 11100000 00000001 Bits:32 Hex: 0000e001 #7:224
134899 LRCLK edge 208: 00000000 00000000 11110000 00000001 Bits:32 Hex: 0000f001 #0:240
135550 LRCLK edge 209: 00000000 00000000 00010000 00000001 Bits:32 Hex: 00001001 #1:16
136201 LRCLK edge 210: 00000000 00000000 01100000 00000001 Bits:32 Hex: 00006001 #2:96
136852 LRCLK edge 211: 11111111 11111111 10010000 00000001 Bits:32 Hex: ffff9001 #3:-112
137503 LRCLK edge 212: 11111111 11111111 01100000 00000001 Bits:32 Hex: ffff6001 #4:-160
138154 LRCLK edge 213: 00000000 00000000 01100000 00000001 Bits:32 Hex: 00006001 #5:96
138805 LRCLK edge 214: 11111111 11111111 00000000 00000001 Bits:32 Hex: ffff0001 #6:-256
139456 LRCLK edge 215: 11111111 11111111 10000000 00000001 Bits:32 Hex: ffff8001 #7:-128
140107 LRCLK edge 216: 11111111 11111111 11000000 00000001 Bits:32 Hex: ffffc001 #0:-64
140758 LRCLK edge 217: 11111111 11111111 10010000 00000001 Bits:32 Hex: ffff9001 #1:-112
141409 LRCLK edge 218: 11111111 11111111 11000000 00000001 Bits:32 Hex: ffffc001 #2:-64
142061 LRCLK edge 219: 00000000 00000000 01110000 00000001 Bits:32 Hex: 00007001 #3:112
142712 LRCLK edge 220: 00000000 00000000 01110000 00000001 Bits:32 Hex: 00007001 #4:112
143363 LRCLK edge 221: 00000000 00000000 10010000 00000001 Bits:32 Hex: 00009001 #5:144
144014 LRCLK edge 222: 11111111 11111111 11010000 00000001 Bits:32 Hex: ffffd001 #6:-48
144665 LRCLK edge 223: 00000000 00000000 01100000 00000001 Bits:32 Hex: 00006001 #7:96
145316 LRCLK edge 224: 11111111 11111111 11000000 00000001 Bits:32 Hex: ffffc001 #0:-64
145967 LRCLK edge 225: 00000000 00000000 11110000 00000001 Bits:32 Hex: 0000f001 #1:240
146618 LRCLK edge 226: 11111111 11111111 11110000 00000001 Bits:32 Hex: fffff001 #2:-16
147269 LRCLK edge 227: 11111111 11111111 11000000 00000001 Bits:32 Hex: ffffc001 #3:-64
147920 LRCLK edge 228: 11111111 11111111 10010000 00000001 Bits:32 Hex: ffff9001 #4:-112
148571 LRCLK edge 229: 11111111 11111111 11110000 00000001 Bits:32 Hex: fffff001 #5:-16
149222 LRCLK edge 230: 00000000 00000000 01100000 00000001 Bits:32 Hex: 00006001 #6:96
149873 LRCLK edge 231: 000000
</pre>
Every N samples (actually every 384 samples), there are two sample with LSB set to 0x09 rather than 0x01.
Counting the channels as seen on the front-panel from 1 to 16, these are marking channels 1 and 2 in the first data stream.
Channels 8 & 9 are I expect marked in the same way, although I don't have a second WM8804 running on that channel yet.
</div>
tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com0tag:blogger.com,1999:blog-19033682.post-33507510189068708022015-07-09T14:09:00.001+00:002015-07-09T14:14:27.406+00:00Low-noise +/-12v linear power supply for Phono Preamp<div dir="ltr" style="text-align: left;" trbidi="on">
Ages ago, I built a John Linsley-Hood design of phono preamp, first published in ETI magazine in 1992. This was considerably better than the phono stage in the integrated amp I was using at the time (a Creek CAS4040).<br />
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For a couple of decades I ran this from my bench power supply, so it was definitely time for its own PSU. Rather than etching my own circuit board, nowadays kits are available via eBay that save a lot of that messy work. I wanted something based on the LM317 / LM337 regulators, as they are known to have superior noise performance and regulation compared to the standard 7812 / 7912 family.<br />
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I started with <a href="http://www.ebay.co.uk/itm/131510744642" target="_blank">this</a> kit. Unpacking, you have a bag of bits and a very nice looking double-sided, through-hole-plated, silk-screen-printed PCB - way better than you can make yourself. And the total price of the kit is less than you'd pay from a regular supplier for the parts. The large electrolytic caps are Sanyo branded, and look genuine to me.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7DOlXsFpKagyiFOWch0KqbJkTKzw9EZoXwZ35iSogoevjcDPGxLQVc2CLKUc3G9CGA0-6KkymCPKNZPcEnsv8e8wW3vh5DzZivsU9zJyrR9M5VawdKt4Uc9a63GIwEw2R4R0S/s1600/P1030890.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="225" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7DOlXsFpKagyiFOWch0KqbJkTKzw9EZoXwZ35iSogoevjcDPGxLQVc2CLKUc3G9CGA0-6KkymCPKNZPcEnsv8e8wW3vh5DzZivsU9zJyrR9M5VawdKt4Uc9a63GIwEw2R4R0S/s400/P1030890.JPG" width="400" /></a></div>
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Here's a view of the PCB sides:</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhF0IUedvxf1m7NGnMJJTBdzNtuHE1-2fU15UEN9aqaSbXvQBm_cjhhQzM3XF3-NOxZOnq4VdEkEDrpxv4SDxB1KxDaqwihvLMUYKi-mW2An-l6YTZXO6DW10J9iCVFTgy8Oyoc/s1600/P1030891.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhF0IUedvxf1m7NGnMJJTBdzNtuHE1-2fU15UEN9aqaSbXvQBm_cjhhQzM3XF3-NOxZOnq4VdEkEDrpxv4SDxB1KxDaqwihvLMUYKi-mW2An-l6YTZXO6DW10J9iCVFTgy8Oyoc/s400/P1030891.JPG" width="400" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiGB7-vyQXIgWcn-YegSC3pkoAz6QGoG2OZzS7ftsCEM3Zesbh54lR47Q-LjFoCQKQZZPFDODS8eSlzHKZ87Ds1Cphxy5-2-j69KyONRlboJcwR6rcAPcGNjr1-QPgYFPcB3m4Z/s1600/P1030892.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiGB7-vyQXIgWcn-YegSC3pkoAz6QGoG2OZzS7ftsCEM3Zesbh54lR47Q-LjFoCQKQZZPFDODS8eSlzHKZ87Ds1Cphxy5-2-j69KyONRlboJcwR6rcAPcGNjr1-QPgYFPcB3m4Z/s400/P1030892.JPG" width="400" /></a></div>
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The negative regulator is branded "On" which is On Semiconductor, formerly Motorola.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh2jgbIUfv7V_6f_ylxtY0zVp8XMJMJx4K04GgcCpbnO73q4OKrERmRYXJlQ0QiNdsvuiImM8Nq2xPwrS5Fv79vt_E-HCYS039bmH-3BFy-dpDHDPWD7XfpWO5b3VdxXuNrkvTQ/s1600/P1030894.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh2jgbIUfv7V_6f_ylxtY0zVp8XMJMJx4K04GgcCpbnO73q4OKrERmRYXJlQ0QiNdsvuiImM8Nq2xPwrS5Fv79vt_E-HCYS039bmH-3BFy-dpDHDPWD7XfpWO5b3VdxXuNrkvTQ/s400/P1030894.JPG" width="400" /></a></div>
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I filed down the burrs on the heatsink holes, removed the anodization/paint with a small file, and applied some PC heatsink paste. Probably overkill, considering that the preamp will draw less than 100mA, but better than overheating.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0mXBsyaJlytWmg0vpuANcNmroYChGFbC0gOsvk1RykyMm6OmaGmVh6WaPMtMDIsy10Ce8X2-q7sg-n5LTNywBIHEOKLFlSWTlz6bdVxX3yqW29IywvmKb6HUau5zTvCwvkngP/s1600/P1030895.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0mXBsyaJlytWmg0vpuANcNmroYChGFbC0gOsvk1RykyMm6OmaGmVh6WaPMtMDIsy10Ce8X2-q7sg-n5LTNywBIHEOKLFlSWTlz6bdVxX3yqW29IywvmKb6HUau5zTvCwvkngP/s400/P1030895.JPG" width="400" /></a></div>
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here's the regulators mounted on the heatsinks, ready to insert in the board.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEigTJMIVluJw1CN8C7MBx_Ey6d2BUQouoavp79_6OJRITvEDuBi6HWb6dPxMyzYwuCObtHdhzMs4GT5jUz9V7F4gRa0UaT4VnDAhA1dpcW9d_-oA7ATOg56jTjhp0ZEwBZk5yqa/s1600/P1030896.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEigTJMIVluJw1CN8C7MBx_Ey6d2BUQouoavp79_6OJRITvEDuBi6HWb6dPxMyzYwuCObtHdhzMs4GT5jUz9V7F4gRa0UaT4VnDAhA1dpcW9d_-oA7ATOg56jTjhp0ZEwBZk5yqa/s400/P1030896.JPG" width="400" /></a></div>
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The circuit diagram supplied with the kit didn't quite match the PCB & kit of parts. Here's a marked-up version of the diagram:</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhi_QM_b79aNCOza2TmuUYRzhh3H0wBzm2CpwzP52eHXIeNM5_xGyOERQg34oEleCRQ_Gxu1630qS6mobAqqYQFLU8TcOuQM1-nn2u_hFiTdv2Zd6ERge5c7BKbV7rdgFHh9zQc/s1600/PSU+circuit+diagram.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="462" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhi_QM_b79aNCOza2TmuUYRzhh3H0wBzm2CpwzP52eHXIeNM5_xGyOERQg34oEleCRQ_Gxu1630qS6mobAqqYQFLU8TcOuQM1-nn2u_hFiTdv2Zd6ERge5c7BKbV7rdgFHh9zQc/s640/PSU+circuit+diagram.jpg" width="640" /></a></div>
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The bypass capacitors around the full-wave rectifier diodes were interesting - I hadn't seen those before. I found <a href="http://electronics.stackexchange.com/questions/14250/what-are-the-advantages-of-full-wave-bridge-rectifier-with-capacitors-parallel-t" target="_blank">this site</a> and <a href="http://www.hagtech.com/pdf/snubber.pdf" target="_blank">this article</a> which explains what they're for.</div>
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Even with the caps in place, some ringing is evident when looking at the transformer secondary taps. While I'm somewhat skeptical that this would ever be audible, let's see if we can do better, based on that second article.</div>
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Firstly, let's add 330R dummy load resistors, so we can test the circuit behaviour without endangering the regulators.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhmdp2kGtgfEAAISwI3DtK_-2Hf17D8p-D13LmjZQZA3khYlUpJOBsStSggnHxgoURAVdie2AIsxcpR-T_5sIG2PdJi9_Vlrp-8weHssR0l6iqbuyGKFJXdxN9SlBJDFXcHIRX7/s1600/P1030901.JPG" imageanchor="1" style="clear: left; display: inline !important; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhmdp2kGtgfEAAISwI3DtK_-2Hf17D8p-D13LmjZQZA3khYlUpJOBsStSggnHxgoURAVdie2AIsxcpR-T_5sIG2PdJi9_Vlrp-8weHssR0l6iqbuyGKFJXdxN9SlBJDFXcHIRX7/s400/P1030901.JPG" width="400" /></a></div>
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The ringing is definitely there on the transformer secondary output:</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjCSCKbejG2ig8vq83vZdnR_ySGjynDbTfJv9a6-f6Xjh_56Sq1UhfnOLtpN_eBPT3_NrYaRx7qN6rUpt8ALDCKctaGubIBZ14bVQ8vk8cY1nlfAYXPLUWW-NJPiTBRFIG66jRY/s1600/P1030898.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjCSCKbejG2ig8vq83vZdnR_ySGjynDbTfJv9a6-f6Xjh_56Sq1UhfnOLtpN_eBPT3_NrYaRx7qN6rUpt8ALDCKctaGubIBZ14bVQ8vk8cY1nlfAYXPLUWW-NJPiTBRFIG66jRY/s400/P1030898.JPG" width="400" /></a></div>
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Here's a closeup of the rising and falling edge ringing:</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMxHpRXYpT5WCT80s-Nt8pxx4vS_fUdvyPJfix5aohJzJAktBeP_pzKQfExANgNQ4G2fl_WlcTH5_DP5qMHZy5b_OcAbHmx2JSLMh9NNDX9eobzfl5W9inW-1ul5ZUO8eFB7mC/s1600/P1030899.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMxHpRXYpT5WCT80s-Nt8pxx4vS_fUdvyPJfix5aohJzJAktBeP_pzKQfExANgNQ4G2fl_WlcTH5_DP5qMHZy5b_OcAbHmx2JSLMh9NNDX9eobzfl5W9inW-1ul5ZUO8eFB7mC/s400/P1030899.JPG" width="400" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcstw249HiLyorwbySbt61Ze3jcuiBtFqRBOK03EdI8rMgoo9vSSgH_x-JovjY85fGQ_7wmFs92jhw8-2M7ZAgEKkE8G9mjO6px_bvce2BLnInHrrnIuqUjscQkaA7sD5Wczne/s1600/P1030900.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcstw249HiLyorwbySbt61Ze3jcuiBtFqRBOK03EdI8rMgoo9vSSgH_x-JovjY85fGQ_7wmFs92jhw8-2M7ZAgEKkE8G9mjO6px_bvce2BLnInHrrnIuqUjscQkaA7sD5Wczne/s400/P1030900.JPG" width="400" /></a></div>
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Now let's add 180R in series with each of the 100n snubber caps. It's a little bit awkward to fit this into the existing PCB, but it's possible.</div>
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Here's the improved damping result.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCG0yyLQsmMb7Prr1mN3-y2oVL7DvKb7zAft3qCb9OW9b-8kUiH994kqGQ05HqFSBWb2h63oJUJ3r3OvGszaEn0Ap7U7A0GMeIsBdxkaqepI8tMTzXQM7SljDW3RMfMNwqVRKl/s1600/P1030902.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCG0yyLQsmMb7Prr1mN3-y2oVL7DvKb7zAft3qCb9OW9b-8kUiH994kqGQ05HqFSBWb2h63oJUJ3r3OvGszaEn0Ap7U7A0GMeIsBdxkaqepI8tMTzXQM7SljDW3RMfMNwqVRKl/s400/P1030902.JPG" width="400" /></a></div>
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Here's the improved R-C snubbers in place.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgon_J8cM0O7FS6yFoM04a3nhL_UgmBztHbUPH6WSinhJjUGwQrTVyHliyVZyXzgZ6WL1GZUM5i72NnnbMLV2eA5J3_rVt1s_dZjvhgMA0L2GYcvqIr_f2CnAhYQOLvJkIy_DgZ/s1600/P1030903.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgon_J8cM0O7FS6yFoM04a3nhL_UgmBztHbUPH6WSinhJjUGwQrTVyHliyVZyXzgZ6WL1GZUM5i72NnnbMLV2eA5J3_rVt1s_dZjvhgMA0L2GYcvqIr_f2CnAhYQOLvJkIy_DgZ/s400/P1030903.JPG" width="400" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgon_J8cM0O7FS6yFoM04a3nhL_UgmBztHbUPH6WSinhJjUGwQrTVyHliyVZyXzgZ6WL1GZUM5i72NnnbMLV2eA5J3_rVt1s_dZjvhgMA0L2GYcvqIr_f2CnAhYQOLvJkIy_DgZ/s1600/P1030903.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-left: 1em;"></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPgD5GpOETaho0z34JZGjayMPIl82wtrbV5GTCitasb24XREC34lMWaeI5XHy_9PQT3pzi4wixIN5Y6EcQZta4-ONlq6vmKhBVcFfI9q1JFLrCg8I0iEOm4vLcpPij41_H57Fi/s1600/P1030904.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPgD5GpOETaho0z34JZGjayMPIl82wtrbV5GTCitasb24XREC34lMWaeI5XHy_9PQT3pzi4wixIN5Y6EcQZta4-ONlq6vmKhBVcFfI9q1JFLrCg8I0iEOm4vLcpPij41_H57Fi/s400/P1030904.JPG" width="400" /></a></div>
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Looking at the 12v outputs, they're pretty clean, with noise below 1mV on each rail.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhFRSM73V8VYiWYqFOCE22ShCCgDGn4jRgZUGeA8Tl84FKpbeOHzmWbdD0BE9dX4NoqipDI3f3oD4mFsZvePAE9GlUNxG58u0pmb7SPlr8hHw7dIJq8Ewi5rln-bMcPbYqN-c2W/s1600/P1030906.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhFRSM73V8VYiWYqFOCE22ShCCgDGn4jRgZUGeA8Tl84FKpbeOHzmWbdD0BE9dX4NoqipDI3f3oD4mFsZvePAE9GlUNxG58u0pmb7SPlr8hHw7dIJq8Ewi5rln-bMcPbYqN-c2W/s400/P1030906.JPG" width="400" /></a></div>
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Ready to connect to the preamp. I used a trailing 7-pin DIN socket for the power (using pins 6 & 7 for -/+12v so they can't be mistakenly connected to audio inputs).<br />
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12v-12v secondary transformer and surge-protected IEC input.<br />
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The finished power supply, mounted inside an <a href="http://cpc.farnell.com/hammond/1594esgy/heavy-duty-gpabs-enclosure-grey/dp/EN84310?ost=1594ESGY" target="_blank">ABS box from CPC</a>.<br />
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I found that, when the preamp is connected to other devices such as USB sound-cards, hum levels were reduced when the power supply 0v output was <b><u>not</u></b> connected to mains earth. Perhaps the PC was already earthing via the sound-card and it was just introducing a ground loop.</div>
tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com1tag:blogger.com,1999:blog-19033682.post-36451275661217970772015-07-03T17:40:00.001+00:002015-07-03T17:49:03.663+00:00Simple electronic water leak detector<div dir="ltr" style="text-align: left;" trbidi="on">
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The following circuit is a very simple water leak detector, which I made 25+ years ago (!!) following my fiancée having a washing machine go wrong and leak all over her apartment.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEfv8-qgApyXwd03WNyp5S4Hev8SA4B_gz0vte6ayyH5ZQdMAJnaCflJ3IWBGoOKIjeh4d3BRFi-j5oUX8ssqVtLSwBza1Kf4oNiK4kj4Y4B_8AylTZEhfPPsB2Avynw_ksf-R/s1600/Screenshot+2015-07-03+18.37.01.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="206" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEfv8-qgApyXwd03WNyp5S4Hev8SA4B_gz0vte6ayyH5ZQdMAJnaCflJ3IWBGoOKIjeh4d3BRFi-j5oUX8ssqVtLSwBza1Kf4oNiK4kj4Y4B_8AylTZEhfPPsB2Avynw_ksf-R/s320/Screenshot+2015-07-03+18.37.01.png" width="320" /></a></div>
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The circuit is not ideal - there are better designs out there. It was built with 'what I had in my scrapbox at the time'. It's purely analog, relying on the gain of the Darlington pair to provide reasonable on/off behaviour. This can actually be an advantage, as the sound will get louder as the leak becomes more serious and conducts more water.<br />
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The transistors used are not critical. I used BC108Cs.</div>
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Battery current drain is essentially zero (too low to measure on my meter) when there's no conduction.</div>
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The physical construction had a few hacks which surprised me when I took it apart again.</div>
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- The self-tapping screws are used both to hold in the buzzer, and act as the electrodes. Kind-of-neat, but soldering on to them was a nasty little shortcut I'm not proud of!</div>
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- The battery is just held in with double-sided tape. Good enough for something that's rarely changed.</div>
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- The circuit board is just loose in the box. Actually I had held it in place with blu-tak before, which was horrible. But the blu-tak seems to absorb moisture and prevents the circuit working properly.</div>
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- The plastic box would cut down the sound level too much. So it has holes cut in the box lid to let the sound out. These holes are then "sealed" using a blu-tak 'grommet' and thin plastic. Reasonable compromise between letting the sound out and not letting water in!</div>
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Here's a pic of the insides.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgduStSzRguoIUxX_HXOR91yaULOP1OSGL1vX9vHJCpG0M-pyo0Tmda5_02_ArA6ZJ0ItbsCXMvKPYEphx70PBarbMOoKIuiR59vhS7ZgHwPI9J9grtnZQ2WF_gRRrXwmQ8bMt7/s1600/P1030889.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="360" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgduStSzRguoIUxX_HXOR91yaULOP1OSGL1vX9vHJCpG0M-pyo0Tmda5_02_ArA6ZJ0ItbsCXMvKPYEphx70PBarbMOoKIuiR59vhS7ZgHwPI9J9grtnZQ2WF_gRRrXwmQ8bMt7/s640/P1030889.JPG" width="640" /></a></div>
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Nowadays, cheap commercial solutions are easily available such as <a href="http://www.amazon.co.uk/Bavaria-BAWM5-Water-Duracell-Battery/dp/B004YK33KQ/ref=sr_1_1?ie=UTF8&qid=1435943219&sr=8-1&keywords=water+detector" target="_blank">this</a>.</div>
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tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com2tag:blogger.com,1999:blog-19033682.post-68794778963513820302013-10-10T21:24:00.001+00:002013-10-28T20:59:12.318+00:00Simple Optical Compressor for bass guitar - construction<div dir="ltr" style="text-align: left;" trbidi="on">
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An extremely simple yet capable compressor circuit is published by Elliott Sound Products, here: <a href="http://sound.westhost.com/project45.htm" target="_blank">http://sound.westhost.com/<wbr></wbr>project45.htm</a><br />
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<h2 style="text-align: left;">
Compressor Mk I<br />
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I built the circuit exactly as-is (in an Altoids tin). <br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5HKAHfq0GjegQV-nBqN-IPdZAag0Esqq3nE5vbXCWllkpT62RWASByoGHkBpSU6yFbgcii4mRFGfpxr5ZtC5JWvYXe_LpHMiTjIMK1hjQG7Hmf0hu5-JaBlImbCFKxZGuNEC9/s1600/P1020194.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5HKAHfq0GjegQV-nBqN-IPdZAag0Esqq3nE5vbXCWllkpT62RWASByoGHkBpSU6yFbgcii4mRFGfpxr5ZtC5JWvYXe_LpHMiTjIMK1hjQG7Hmf0hu5-JaBlImbCFKxZGuNEC9/s640/P1020194.JPG" height="480" width="640" /></a></div>
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Care was taken to optically couple the bulb to the photocell (LDR), using a perspex rod, wrapped in smooth tin-foil. The perspex came from eBay:<br />
<a href="http://stores.ebay.co.uk/thewholesaleposco2009">http://stores.ebay.co.uk/thewholesaleposco2009</a><br />
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as did the miniature "Grain of Wheat" bulbs: <a href="http://stores.ebay.co.uk/GnA-MODELPARTS?_trksid=p2047675.l2563">http://stores.ebay.co.uk/GnA-MODELPARTS?_trksid=p2047675.l2563</a><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjMm64UltAJoyjVuWjulDnpQffRANtook0jPjkN6YN6PA5WRg5L1g6GW2VpJiXR9nmZaNv8vqz_N5p9ZjE31IMyISh8UmiFrUuTagPkSZyLGeFFQ5TzJTR3rM06M8kGD1qU0cLW/s1600/P1020195.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjMm64UltAJoyjVuWjulDnpQffRANtook0jPjkN6YN6PA5WRg5L1g6GW2VpJiXR9nmZaNv8vqz_N5p9ZjE31IMyISh8UmiFrUuTagPkSZyLGeFFQ5TzJTR3rM06M8kGD1qU0cLW/s640/P1020195.JPG" height="480" width="640" /></a></div>
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This was put together, and sealed in heatshrink tubing, to make it fairly lightproof from external light sources. The rest of the components came from <a href="http://cpc.farnell.com/">http://cpc.farnell.com</a> (free postage) or from my junk box.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAqv6ybLrVeBLAxU7vLUA6QuiTtsVRoMt0Kxl0yNQylEP8ORIZV_1D_qP18u6eVpGubcbZv-NwhN8F4UevdnxS3FZ7HSL8GHNxWdgT4hlY40nzoSgGioVUEYYQQeboQ8xhzUZC/s1600/P1020196.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAqv6ybLrVeBLAxU7vLUA6QuiTtsVRoMt0Kxl0yNQylEP8ORIZV_1D_qP18u6eVpGubcbZv-NwhN8F4UevdnxS3FZ7HSL8GHNxWdgT4hlY40nzoSgGioVUEYYQQeboQ8xhzUZC/s640/P1020196.JPG" height="480" width="640" /></a></div>
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Here's the final assembly. The green wire provides grounding (shielding) for the tin-foil, as per the original article description.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwJRDqUItpn7c2kq-U1Vg8mvQm80wg6dH28Pe9ICUd9goaIH2GZVaK7FWBg5PwVDithF9tDpVfY6jF9fe8D9tHN8dXfQJzg_gl1AfRX79PCm0xEtKW4P0MBBcW0hvd8PSpHa41/s1600/P1020197.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwJRDqUItpn7c2kq-U1Vg8mvQm80wg6dH28Pe9ICUd9goaIH2GZVaK7FWBg5PwVDithF9tDpVfY6jF9fe8D9tHN8dXfQJzg_gl1AfRX79PCm0xEtKW4P0MBBcW0hvd8PSpHa41/s640/P1020197.JPG" height="480" width="640" /></a></div>
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Here's the finished article. The Altoids tin was really too small, so I had to cut notches in the lid, which rather spoiled the look.<br />
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The duck tape on the bottom of the box provides insulation. The whole tin is effectively coupled to the amp "earth" via the jack socket outer rings.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiK0sC4jgFrtkyBIbBK-Y99zr5gMkdoNrVBPcU3i_Tjm4vL6Kz9CLVVLdf0ivTcOOrTWcbyjuTwsRPjdWyqgPTzz1lNrZ3M0JUDqOVZOb6NhZSFkAjO0sDVebAGAptwqYRxZ8di/s1600/P1020199.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiK0sC4jgFrtkyBIbBK-Y99zr5gMkdoNrVBPcU3i_Tjm4vL6Kz9CLVVLdf0ivTcOOrTWcbyjuTwsRPjdWyqgPTzz1lNrZ3M0JUDqOVZOb6NhZSFkAjO0sDVebAGAptwqYRxZ8di/s640/P1020199.JPG" height="480" width="640" /></a></div>
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I soon discovered the following:<br />
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<li>Using jack-sockets to carry high-current, low-impedance amp output signals is a very dumb idea. I knew this before, I just kind-of forgot it in the urge to get everything to fit in an Altoids tin. Even with the amp output muted (but powered), I got a fat blue spark when unplugging the box. </li>
<li>The "grain of wheat" bulbs don't really get into their proper operating range of brightness when you have an efficient speaker cabinet (like a <a href="http://www.barefacedbass.com/">www.barefacedbass.com</a> one) - even when the variable resistor is turned right up.</li>
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My amp has an FX send / return loop, so I was using that for the input side (on the left). The two speaker sockets (on the right) were there in case a "pass thru" was needed, although again my amp has two speaker-outs, so no need to use that in practice.</div>
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I was a bit concerned about the way the tin was earthing together the FX send/return loop with the "-" side of the amp output. It worked fine for the two amps I tried, but what would happen if it was connected to an amp in bridge-mode where the "+" and "-" sides were both driven? Clearly not ideal.</div>
<h2 style="text-align: left;">
Compressor Mk II</h2>
Mk II was going to be built in a proper case, with a Speakon plug on a trailing lead (so it simply cannot be plugged in wrongly), and would use a high-efficiency LED with suitable dropper resistors instead of the bulb (so as to be more effective at low amp output levels).<br />
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It would also have electrical isolation between the amp out / speaker side, and the delicate FX send/return loop (which will be used for a shielding / ground connection for the case).<br />
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Here it is:<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgSNE1vj7f2tahh8DABuoOIIurOYIFpUDmZ0dtD9KaJmHjBvK-R54NzEalu0BD6s8lu5ZBj7PJ9Xu8TSSSNrdUQREAhFMd_Mt6v-zHixAxFw0azC0vygWv1lFDCAn7N95qKPjKF/s1600/P1020200.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgSNE1vj7f2tahh8DABuoOIIurOYIFpUDmZ0dtD9KaJmHjBvK-R54NzEalu0BD6s8lu5ZBj7PJ9Xu8TSSSNrdUQREAhFMd_Mt6v-zHixAxFw0azC0vygWv1lFDCAn7N95qKPjKF/s640/P1020200.JPG" height="480" width="640" /></a></div>
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The Speakon cable enters through a grommet, is double tie-wrapped to the floor of the case, so even your clumsy drummer friend shouldn't damage it.<br />
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The variable resistor is a 5 watt, 500 ohm type which I found on eBay: <br />
<a href="http://stores.ebay.co.uk/Interesting-Electronics?_trksid=p2047675.l2563">http://stores.ebay.co.uk/Interesting-Electronics?_trksid=p2047675.l2563</a><br />
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You'll notice a pair of 47 ohm fixed resistors, in parallel, on the green input wire next to the variable resistor. In parallel that makes around 24 ohms. The purpose of that, is to prevent the last little bit of the variable resistor's track dissipating a lot of power. In fact it's hardly necessary as the LEDs use less power than the bulbs. I used two small resistors in parallel because they have a low power rating (I think 1/4 watt) and didn't want them to get too hot.<br />
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Because LEDs can "flash" much faster than a bulb can, and only respond to current in one direction, we need a "rectifier and smoother" circuit. This is what the small diode and big capacitor does.<br />
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The capacitor is 470uF, 25v (from the junk box). Voltage rating is important, as your amp can produce quite high peak voltages. Make sure you use at least a 25v rated one, higher if you can - preferably 63v. <br />
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The output of the capacitor feeds two separate LED circuits. The first one has 2x 220 ohm in parallel (effectively 110 ohm) feeding the high-efficiency LED that is inside the shrink wrap. Because the LED light output is very directional, I did not use the perspex rod - I just put the LED right up against the front face of the LDR.</div>
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The second circuit goes through 470 ohms to a small front-panel LED. The idea being that you can see what the compressor is doing from the outside.<br />
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The final part of the circuit is the same as the Elliott original. A 33k resistor couples the input side (amp: FX SEND) to the output side (amp: FX RETURN), forming a potential divider with the LDR. </div>
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With the lid off in the dark, you can see both LEDs are working together.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj_5RJQWQ5GPUS-ACqt084LvpmkeCRdTDk6EtAj8PO46CW_eKeabLYZYtSZ7sCgJBP9KFBID0X8DGv_S9HI4oxFjmJHv_O6L1du7lYTYApOkIsKKcYXGzN9ACShjlz-uemE6ZYh/s1600/P1020204.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj_5RJQWQ5GPUS-ACqt084LvpmkeCRdTDk6EtAj8PO46CW_eKeabLYZYtSZ7sCgJBP9KFBID0X8DGv_S9HI4oxFjmJHv_O6L1du7lYTYApOkIsKKcYXGzN9ACShjlz-uemE6ZYh/s640/P1020204.JPG" height="480" width="640" /></a></div>
<br />
The case was sprayed a non-Ashdown blue, and a nice quality collet knob from CPC/Farnell added.<br />
<br />
The final circuit seems to work well - the component values will need some tweaking to suit your amp / cabinet combination. If you want a circuit that is less sensitive to amp/cab variations then you might want to look at the other Elliott pages.<br />
<br />
Circuit diagram:<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhYx1ymTpbeRmfFb6kaf4dLF2a6Qcaineiuy-_za7-cRHKoalG1eXXmfIDpvN5JMePI-cAwot49dfG5TJeSj7pAK9p6u8y2fL09J-6Q0DRAD2QY9FiGcOwyUM7jEuw1Typ_NcAR/s1600/Passive_Optical_Compressor.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhYx1ymTpbeRmfFb6kaf4dLF2a6Qcaineiuy-_za7-cRHKoalG1eXXmfIDpvN5JMePI-cAwot49dfG5TJeSj7pAK9p6u8y2fL09J-6Q0DRAD2QY9FiGcOwyUM7jEuw1Typ_NcAR/s640/Passive_Optical_Compressor.png" height="235" width="640" /></a></div>
Free download in <a href="http://www.thetucks.com/BassComp/Bass%20Guitar%20Passive%20Compressor.pdf" target="_blank">PDF</a><br />
and <a href="http://www.thetucks.com/BassComp/Bass%20Guitar%20Passive%20Compressor.sch">ExpressPCB</a> .sch format (R-click / Save As) .. software available <a href="http://www.expresspcb.com/expresspcbhtm/Free_schematic_software.htm" target="_blank">here</a><br />
<br />
<br />
<br /></div>
tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com0tag:blogger.com,1999:blog-19033682.post-43051775499148101122013-07-11T19:35:00.000+00:002013-07-11T19:35:10.893+00:00Sony Vaio VPCEB4L1EWI - Heatsink clean and refit<div dir="ltr" style="text-align: left;" trbidi="on">
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<span style="font-size: small;"><span style="font-family: inherit;">This time, it's a Sony Vaio VPCEB4L1EWI, with i3-380M CPU. About two
years old. Running Prime95 stress test, the cores were reaching 85 deg C
and the fan was rather noisy.</span></span></div>
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<span style="font-size: small;"><span style="font-family: inherit;">1. Strip off the back plate, undoing all the visible screws, taking
careful note of where they all go back - there are several different sizes and
types. The back plate then snaps off - be careful with the small white
lugs on the upper side here. One came off despite me taking care. </span></span></div>
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<span style="font-size: small;"><span style="font-family: inherit;">Always wear an anti-static wrist strap, connected to a metal part of the
laptop (e.g. the USB connector) when working.</span></span></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj4pRErKFhS3iBMkjbz0zvR5MGTx2_NyMn6Jioi45l2iY4Jrg2HRHA0-2ar8fBI5165gcA3kzCRzrV_cAwrTBA8Jh2APVR-p7HemStQ2S3Lwkbjm4qMxOkzICtkVr9_aIHnHHfe/s1600/P1010640.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj4pRErKFhS3iBMkjbz0zvR5MGTx2_NyMn6Jioi45l2iY4Jrg2HRHA0-2ar8fBI5165gcA3kzCRzrV_cAwrTBA8Jh2APVR-p7HemStQ2S3Lwkbjm4qMxOkzICtkVr9_aIHnHHfe/s640/P1010640.JPG" width="640" /></a><span style="font-size: small;"></span></div>
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<span style="font-size: small;"><span style="font-family: inherit;">2. Here is the heatsink / heat pipe / fan assembly removed. The
grey heatsink paste had set quite hard.</span></span></div>
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<span style="font-size: small;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjh7G7AXWsZ_yoS_IhfHDKq89HvYpq8vI9xiDXgWm45Wup0VPOK0VVW_VU1qnCKtyhVVdDYnBTcexIFLrr1ID8KDZ_Rk-Qx5-Z0aMoFSZSz2j6EmELD-MjQsew1HJXhdgUyY_X8/s1600/P1010641.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="592" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjh7G7AXWsZ_yoS_IhfHDKq89HvYpq8vI9xiDXgWm45Wup0VPOK0VVW_VU1qnCKtyhVVdDYnBTcexIFLrr1ID8KDZ_Rk-Qx5-Z0aMoFSZSz2j6EmELD-MjQsew1HJXhdgUyY_X8/s640/P1010641.JPG" width="640" /></a><span style="font-family: inherit;"> </span></span></div>
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<span style="font-size: small;"><span style="font-family: inherit;">3. Clean up the CPU top surface carefully with meths, a cloth, and
cotton buds. </span></span></div>
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<span style="font-size: small;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgs7HveoZ-15iv0YwnvZxJTOoI4j9qDfwQpDQs7EbIFQy61J856d1DOR_jQblVUVFenySFRhGQ0F22qPDqj84kJJptVYyCy9TPkst-DB9Zvus_9QyvCMbPjd-L4D_r2uueYMHUE/s1600/P1010642.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgs7HveoZ-15iv0YwnvZxJTOoI4j9qDfwQpDQs7EbIFQy61J856d1DOR_jQblVUVFenySFRhGQ0F22qPDqj84kJJptVYyCy9TPkst-DB9Zvus_9QyvCMbPjd-L4D_r2uueYMHUE/s640/P1010642.JPG" width="640" /></a><span style="font-family: inherit;"> </span></span></div>
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<span style="font-size: small;"><span style="font-family: inherit;"> 4. Clean all the old paste off the heatsink.</span></span></div>
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<span style="font-size: small;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjEGg6NtYSIEhhjwOMasDLG9oEbFmHM6YZL_BIdaEivuT-lCeGVc444Gh0x7unZx0ksK3o3YaPt1TTgm4E5SQcKiyQSbhyphenhyphenSLdqQfppfxSmkx4hVyuJgsReDHpj685mVvsNXUwA7/s1600/P1010643.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjEGg6NtYSIEhhjwOMasDLG9oEbFmHM6YZL_BIdaEivuT-lCeGVc444Gh0x7unZx0ksK3o3YaPt1TTgm4E5SQcKiyQSbhyphenhyphenSLdqQfppfxSmkx4hVyuJgsReDHpj685mVvsNXUwA7/s640/P1010643.JPG" width="640" /></a><span style="font-family: inherit;"> </span></span></div>
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<div style="text-align: left;">
<span style="font-size: small;"><span style="font-family: inherit;">5. To do a really good job, "flat" the heatsink down with a
diamond file, cleaning the copper dust off regularly. I kept applying a
few drops of meths as a non-greasy lubricant while working.</span></span></div>
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<span style="font-size: small;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-fE701GCRyKTcD8jxc84uRiZNwrJtNN95A43qtqd7t3LvXOMI-uVixhVEsZwcWV2OvJJpmPe2owIpnAWPzrCT9mu80bXfVeUyY_PBLhawchR3NnDHbWinC_5Y8W5b_w1FpQDB/s1600/P1010644.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-fE701GCRyKTcD8jxc84uRiZNwrJtNN95A43qtqd7t3LvXOMI-uVixhVEsZwcWV2OvJJpmPe2owIpnAWPzrCT9mu80bXfVeUyY_PBLhawchR3NnDHbWinC_5Y8W5b_w1FpQDB/s640/P1010644.JPG" width="640" /></a><span style="font-family: inherit;">After a few minutes you should be able to get a near mirror-finish on the
heatsink. Don't over do it - copper is a very soft material.</span></span></div>
<div style="text-align: left;">
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<span style="font-size: small;"><span style="font-family: inherit;"><span></span></span></span></div>
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<span style="font-size: small;"><span style="font-family: inherit;">7. Apply a new heatsink paste (I used Arctic MX-4), and re-assemble
the machine.</span></span></div>
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</div>
<div style="text-align: left;">
<span style="font-size: small;"><span style="font-family: inherit;">Measuring the core temperature with "CPUtemp" and running
"Prime95" stress test, the peak core temp reached 68 deg C instead of
85, and the fan ran much quieter as a result.</span></span></div>
<span style="font-size: small;">
</span></div>
tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com0tag:blogger.com,1999:blog-19033682.post-78217409060986532612013-06-07T10:28:00.002+00:002013-06-07T10:29:15.922+00:00Building a quick & easy website .. pros and consJust finished the first draft of a website for my wife's <a href="http://stepuptutors.co.uk/" target="_blank">home tutoring business</a>. I used the free web site builder tools from <a href="http://serversfree.com/" target="_blank">serversfree.com</a>, and they're not bad. A few things we came across were a bit frustrating however:<br />
<br />
<ul>
<li>Once you've chosen your template, the background image (in our case, of the coloured pencils) seems to be unchangeable</li>
<li>There's no "undo" button, so use the "Save and Publish" option frequently to avoid losing work</li>
<li>When you create a new menu item (on the top row, in our case), it throws away work you've just done on your current page, so <i>save it first!</i></li>
<li>Working with images is somewhat frustrating in terms of positioning, resolution etc</li>
</ul>
<br />
There are also good things about the sitebuilder: The sites look good on iPhone and Android devices as well as on a PC / Mac.<br />
<br />
<i> </i><br />
I also noticed that when running this auto-generated page through W3C Validator, it finds 5 "errors". Hmmm.<br />
<br />
I looked around for help pages, or a forum on this
website builder too, to no avail. Anyway I should probably be using
something "proper" like Wordpress, Joomla or even good old Dreamweaver.
Thoughts /comments appreciated.tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com0tag:blogger.com,1999:blog-19033682.post-45468623163894944752013-02-04T00:03:00.000+00:002013-02-04T00:20:45.716+00:00Improving an Ashdown Little Giant bass amplifierI have an Ashdown Little Giant amp. Several reviewers have mentioned that this amp is not at loud as it should be (e.g. <a href="http://www.talkbass.com/reviews/showproduct.php/product/1334/title/ashdown-little-giant-1000/cat/25" target="_blank">here</a>). <br />
<br />
It all depends on whether the output levels coming from your bass are enough to drive the output stage fully. I have an active bass, but even with the input set on max, to get a decent output level I need the output volume control set to around 3 o'clock.<br />
<br />
While there are workarounds available, e.g. use an effects send/return through a pedal which has some gain, I wanted a simple 'no extra boxes' solution to go with my lightweight cab.<br />
<br />
A nice chap called Wilfried Klaas has come up with what I consider to be the perfect solution to this - adding an extra small preamp (gain) stage inside the amp itself. His <a href="http://klaas.homeip.net/wb/pages/diy/amps/ashdown-little-giant-350.php" target="_blank">web page</a> (in German) describes this improvement.<br />
<br />
Wilfried was very helpful and supplied me a ready-made amp board for around €15.00. This was fairly straightforward to fit. I've recorded the process of testing the amp, fitting the board, and re-testing the amp.<br />
<br />
Incidentally - my amp, purchased off Ebay, started off life as a green-front, LG350. However something strange had been done to it, the fan was wired to run continuously off the 12v supply, rather than being connected to the variable-speed fan output. Eventually the power module failed, and it went back to Ashdown, who replaced it with a <a href="http://www.powersoft-audio.com/en/products/amp-modules/digimod/digimod-1000.html" target="_blank">Powersoft Digimod 1000</a> module. Only one side is connected and used, so I have effectively an "LG500".<br />
<br />
<h3>
<u>1. Measure the amp's existing output</u></h3>
First, I hooked up the amp's instrument input to a sine-wave source. I used a 1kHz, 0dB digital source which you can get hold of <a href="http://www.thetucks.com/Audio_test.htm" target="_blank">from here</a>. This was loaded as a .wav file onto an IPod. The output from the iPod was checked on a scope; above 90% volume there were some signs of clipping (presumably the iPod's headphone output stage). This input level was just enough to light up the 'peak' light on the LG's input stage.<br />
<br />
The amp output was connected to a 4 ohm dummy load, which I made as follows - two 8.2 ohm resistors on big heatsinks, connected in parallel, as shown here.<br />
<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhLpf-mR5uca-86j6382EK8WcpnsdiDYO0UnIebcI4diqf5FkJ_6qBOdhCZCC3r6bWS9U81I9zzpqVQS91pnNOyO3RpaJbeJLVm_zqQaGYRGlqgfm1VZfLyoTq95jTHWynYKD04/s1600/P1010446.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhLpf-mR5uca-86j6382EK8WcpnsdiDYO0UnIebcI4diqf5FkJ_6qBOdhCZCC3r6bWS9U81I9zzpqVQS91pnNOyO3RpaJbeJLVm_zqQaGYRGlqgfm1VZfLyoTq95jTHWynYKD04/s1600/P1010446.JPG" width="300" /></a></div>
<br />
For the actual test, these were placed on a metal tray, on a wooden board, as they <i>will</i> get hot if you run the amp into the loads for more than a few seconds.<br />
<br />
With a sine wave input, the amp produced a maximum output of around +/- 60 volts peak, shown here:<br />
<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjhVQPnvt_Wz19rHwjAESB9sxanVyUSNbs71h-2OPu7vYcr2_TYyePkKqxhxrRsgZf7xRA17Gr2X0QHok4aAaDS14Oih5pvLQZ0eoiRoEWdTf12k6xXgtakA5Lg2H97EOlbk-JR/s1600/P1010451.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="288" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjhVQPnvt_Wz19rHwjAESB9sxanVyUSNbs71h-2OPu7vYcr2_TYyePkKqxhxrRsgZf7xRA17Gr2X0QHok4aAaDS14Oih5pvLQZ0eoiRoEWdTf12k6xXgtakA5Lg2H97EOlbk-JR/s1600/P1010451.JPG" width="320" /></a></div>
The RMS power in a sine wave is<br />
<br />
(V^2 / R) / (sqrt(2)) = (3600 / 4) / 1.41 = 636 watts<br />
<br />
After a few seconds, some kind of power limiter kicks in, presumably in the power amp module itself, and the output falls to 44 volts peak, which is<br />
<br />
(1936 / 4) / 1.41 = 343 watts.<br />
<br />
So the amp can produce more than the rated power (for short periods), the problem is down the lack of gain.<br />
<br />
<h3>
<u>2. Fitting the "Wilfried Klass" buffer stage</u></h3>
Firstly, switch the amp off and unplug the mains lead, leaving the load connected to dissipate the internal power, and take the top off the amp case. The cooling fan has a 3-pin connector which looks very similar to PC-type cooling fans, this is easy to remove.<br />
<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjxLMSjnF0DhAzem0TMjZca1mBHTTXBlBhY7xl6tdokyiFr8fWvPSxAMg2A5WSVLF2_kxpRxRosLdD5B-1t1HkHckUysCa7JuxvH9Yiab0TgXy9tJSpCswH3v4FrrzbpieDAWBW/s1600/P1010447.JPG" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="261" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjxLMSjnF0DhAzem0TMjZca1mBHTTXBlBhY7xl6tdokyiFr8fWvPSxAMg2A5WSVLF2_kxpRxRosLdD5B-1t1HkHckUysCa7JuxvH9Yiab0TgXy9tJSpCswH3v4FrrzbpieDAWBW/s1600/P1010447.JPG" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Inside of Little Giant amp</td></tr>
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The white wires on the bottom left carry mains electricity, and even the +/- 60v output from the amp could deliver a shock, so always work with the power off.</div>
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The module requires + / - 12v DC power and an earth, which are obtained from the green connector following Wilfried's instructions.</div>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEij21n9w_fCmL5d1cS1lvzHea70gtSKPM7q_qnh4gJxm8UzPeifWuG6qWl5coeFyV9g-kCBno0xwl0tRWWaAiW9ggzKrkGTJUAkTuYDLTicc2WDKQ58GmNY6MPNNvxUhqFGq_VR/s1600/P1010448.JPG" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEij21n9w_fCmL5d1cS1lvzHea70gtSKPM7q_qnh4gJxm8UzPeifWuG6qWl5coeFyV9g-kCBno0xwl0tRWWaAiW9ggzKrkGTJUAkTuYDLTicc2WDKQ58GmNY6MPNNvxUhqFGq_VR/s1600/P1010448.JPG" width="275" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Power connector On Digimod 1000 module</td></tr>
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The next step is to find and break into the grey ribbon cable that goes from front to back. , on the right side of the amp.<br />
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The third wire from the bottom carries the preamp signal. This needs to be picked out of the ribbon and cut into. I used the scope at this point to check that the sine wave signal was indeed on pin 3<br />
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before I cut into it. I broke into the cable carefully using a craft knife:<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgTyzCijVufW1FM0BUJbLK4dHnUQsH74JTDxEVMpOWdvrJyuNMVSyByF8dNRnRy9wq14MZAXIawXAXBvqx0SuLEU1seyDtOfmszYBehJKzfnEwUJLEVG3o6wvaB6_ICdz_yCxwA/s1600/P1010449.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgTyzCijVufW1FM0BUJbLK4dHnUQsH74JTDxEVMpOWdvrJyuNMVSyByF8dNRnRy9wq14MZAXIawXAXBvqx0SuLEU1seyDtOfmszYBehJKzfnEwUJLEVG3o6wvaB6_ICdz_yCxwA/s1600/P1010449.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgTyzCijVufW1FM0BUJbLK4dHnUQsH74JTDxEVMpOWdvrJyuNMVSyByF8dNRnRy9wq14MZAXIawXAXBvqx0SuLEU1seyDtOfmszYBehJKzfnEwUJLEVG3o6wvaB6_ICdz_yCxwA/s1600/P1010449.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="165" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgTyzCijVufW1FM0BUJbLK4dHnUQsH74JTDxEVMpOWdvrJyuNMVSyByF8dNRnRy9wq14MZAXIawXAXBvqx0SuLEU1seyDtOfmszYBehJKzfnEwUJLEVG3o6wvaB6_ICdz_yCxwA/s1600/P1010449.JPG" width="400" /></a></div>
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The buffer circuit is then connected up, with the <u>input</u> coming from the front panel, and the <u>output</u> going towards the back panel:<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgv5DdWEJe2J-Y6Wf7XcIZf4W8C1xQ-D_pOo24puQXLQFsToX-hR3GA_D5Z8L8qRcc3YJGSadhUpX-8wh1Uv2cEis1loWMcRFzFYSXxQ952r9aF6w9c2LQwZB2owgiI1ExuNajH/s1600/P1010450.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="229" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgv5DdWEJe2J-Y6Wf7XcIZf4W8C1xQ-D_pOo24puQXLQFsToX-hR3GA_D5Z8L8qRcc3YJGSadhUpX-8wh1Uv2cEis1loWMcRFzFYSXxQ952r9aF6w9c2LQwZB2owgiI1ExuNajH/s1600/P1010450.JPG" width="320" /></a><br />
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I then powered up and tested the amp was working, but this time maximum output was reached (before onset of clipping) at a lower setting on the output knob. The limiter behaviour is the same as before.<br />
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Finally, the buffer circuit was fitted into the insulating sleeve supplied by Wilfried (red colour in the picture below). I used double-sided sticky tape to secure this to the inside of the case, and tie-wraps to keep the wiring in place.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgNYgdKg5IRG4Icmi3jl1F5ghHdGmQD6GZbkPRRQwUlWJrG05NJcH9xr-nhmXSzfBefRZn8qr4O_SDrb8-qEgwSt3wKaOr1-O0pQLfw64T61Rgp1kPnBMhch3dU2RDt7VHZULw3/s1600/P1010453.JPG" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgNYgdKg5IRG4Icmi3jl1F5ghHdGmQD6GZbkPRRQwUlWJrG05NJcH9xr-nhmXSzfBefRZn8qr4O_SDrb8-qEgwSt3wKaOr1-O0pQLfw64T61Rgp1kPnBMhch3dU2RDt7VHZULw3/s1600/P1010453.JPG" width="320" /></a></div>
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Having just used the amp in a band rehearsal, I would say it's a great improvement - performance volume levels can be reached, while there's still some 'reserve' on the output knob. There is no appreciable increase in the level of hiss or hum from the amp (it's pretty quiet both before and after the mod).<br />
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So thanks to Wilfried for making an OK amp (available for reasonable money on EBay) into a great little amp.<br />
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<span style="font-family: Arial,Helvetica,sans-serif;">Helping my son revise for a maths test .. most of the questions seemed a bit dull and unlikely to catch a boy's imagination, so I made this one up for him.</span><br />
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<i>A crazy sniper shoots a high velocity bullet vertically upwards. The muzzle exit velocity was previously measured on a firing range, using an accurate timing device, to be 980m/s.<br /><br />Use the simple equations of motion (known as the SUVAT Equations .. available on <a href="http://en.wikipedia.org/wiki/SUVAT_equations#Constant_linear_acceleration" target="_blank">thickipedia here</a>) to calculate</i><br />
<i><br />A) the time the bullet takes to reach the top of its trajectory<br />B) how high it goes<br />C) bonus mark : could the gun have shot a hole through the Red Bull Stratos balloon just before Felix jumped?</i></div>
tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com0tag:blogger.com,1999:blog-19033682.post-72525123502985155942012-10-30T23:02:00.002+00:002012-10-30T23:24:45.791+00:00Sony Vaio VPCF13M0E - CPU heatsink clean and re-fit<div dir="ltr" style="text-align: left;" trbidi="on">
My work laptop (a Sony Vaio VPCF13M0E) had become very noisy, with the fan running full speed as soon as it did any actual work. A bit of googling found that this was a common problem. The original heatsink paste becomes dried up, and doesn't conduct heat well.<br />
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Here's some pictures of the steps I took to fix it. Obviously ONLY ATTEMPT THIS if you know what you're doing, and the machine is out of warranty.<br />
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Time taken: 2 to 3 hours total. <br />
You will need:<br />
<ul style="text-align: left;">
<li>Small cross-head screwdriver</li>
<li>Anti-static wrist strap</li>
<li>Heatsink paste</li>
<li>Methylated spirits</li>
<li>Cotton buds, kitchen roll</li>
<li>Somewhere safe to put all those tiny screws - I recommend a large blank sheet of paper (with a drawing of the back of the machine) to put the screws down onto</li>
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1. Remove the battery, and all the screws on the back plate. Keep careful note (with a drawing of the back of the machine) where all the screws go. There are several different kinds, and a few little tricks.<br />
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Remove the screws - on the back<br />
- inside the battery compartment<br />
- near the battery connector<br />
- covering the RAM (middle plate)<br />
- covering the hard disk (lower left)<br />
- holding the hard disk in.<br />
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The optical disk drive can be pulled out of the machine, revealing three small screws (on the left).<br />
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I counted 24 screws in total.<br />
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Next is the tricky bit. The plastic back plate can be gently lifted off, taking care to not stress the USB, SATA, ethernet and VGA sockets on the right of this picture. Nearly there!<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiaF8qu5bQtXY8PU4JpPFcc59MoRc7R4hVggFuVoJs8jdpvVZXA7Cjj0DGMzdU-wSoTYSlzl-30agkPtmk1N8U-nAAxKpehN0dQJsx8_vinmFiAKIa8fu_m48K1jA2u31zptpEK/s1600/P1010410.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiaF8qu5bQtXY8PU4JpPFcc59MoRc7R4hVggFuVoJs8jdpvVZXA7Cjj0DGMzdU-wSoTYSlzl-30agkPtmk1N8U-nAAxKpehN0dQJsx8_vinmFiAKIa8fu_m48K1jA2u31zptpEK/s640/P1010410.JPG" width="640" /></a></div>
2. Wear an anti-static wrist-strap for this next stage. You can see mine is clipped onto the metal part lower-right.<br />
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The CPU and GPU heatpipe plates are held on by springy metal strips and four screws each. Take these off and keep them separately. Remove the small fan connector from the motherboard.<br />
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Once it's free to move, ease the plates away very gently from the top of the CPU and GPU chips. Some dried paste will be left behind on each one.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWeIkNhrFlz4cYWt7US1VOib2tO8j5D7PeNCxmwzSowHagSYgq03yvCIkSmEqHzkUGaJVICrq90ItRJtmX6Sbcnv907vfLtcKzPd3FeUZw98iQ7RbqAvGx8CNyYnyxanz_VtyS/s1600/P1010411.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWeIkNhrFlz4cYWt7US1VOib2tO8j5D7PeNCxmwzSowHagSYgq03yvCIkSmEqHzkUGaJVICrq90ItRJtmX6Sbcnv907vfLtcKzPd3FeUZw98iQ7RbqAvGx8CNyYnyxanz_VtyS/s640/P1010411.JPG" width="640" /></a></div>
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3. Clean all the old grey gunk off the plates with cotton buds and methylated spirit. Very carefully clean around the CPU and GPU chips with cotton buds/meths, making sure not to damage any of the small surface-mount components.<br />
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4. Examine the state of the heatpipe. There should be no leaks or other damage.<br />
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I found that the copper heat plates that go onto the CPU and
GPU, were not very flat! You can see the ridge marks where it has a concave bit.<br />
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A bit of work with a diamond file got them to
be much flatter (this picture was taken about half way through the flatting work). Only do this if you are confident and skilful with this kind of work; you should still get OK but not ideal results if you just clean (but don't flatten) the heat plate.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjBu8-_xApPzgIx0r6-hMwKAH8YC7vh0iIq_1pQDiIQSFSI118HItQ0e-r7_3J9KULF1ruKA4NB2Q3_Vu_Jl9EKZlhN7Nkg9qbWnkNDRzd3GmX6bDAcjvHzds9ZFP15A0CJfvFp/s1600/P1010412.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjBu8-_xApPzgIx0r6-hMwKAH8YC7vh0iIq_1pQDiIQSFSI118HItQ0e-r7_3J9KULF1ruKA4NB2Q3_Vu_Jl9EKZlhN7Nkg9qbWnkNDRzd3GmX6bDAcjvHzds9ZFP15A0CJfvFp/s640/P1010412.JPG" width="640" /></a></div>
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Take care not to remove too much material! Keep cleaning both the file
and the work with methylated spirit to avoid build-up of copper particles that could leave deep
scratches.<br />
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4. Finally you should have everything clean and ready to put back together.<br />
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Apply a thin coat of good quality heatsink compound (I used Arctic Silver). The amount I've put on here is plenty - any more will just get squeezed out and be wasted.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEibLuE5ybNodFU0HJWVZDQWehquwOn00j-fRbUpsAOZpEEsRm9aOVjtBhl1ZhV3cCt4eIW0RFZtNAnNk7U-ga_dzRPpNalt3MoOzN9UEw1oVjEMCzkamfGo4r82t-fnP0B7bNTt/s1600/P1010413.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEibLuE5ybNodFU0HJWVZDQWehquwOn00j-fRbUpsAOZpEEsRm9aOVjtBhl1ZhV3cCt4eIW0RFZtNAnNk7U-ga_dzRPpNalt3MoOzN9UEw1oVjEMCzkamfGo4r82t-fnP0B7bNTt/s640/P1010413.JPG" width="640" /></a></div>
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5. I gave the heat plate springs a gentle tweak to make sure they were pushing the plates down. I also gently cleaned the fan blades with a paint brush and hoover to remove dust. There wasn't much dust build-up on the actual heat sink blades.<br />
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6. Re-fit the heatpipe carefully. It's best to work slowly and fit screws in diagonal opposites i.e.<br />
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1 4<br />
3 2<br />
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7. Fit the back of the laptop back on, and re-fit all the parts and screws.<br />
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8. Finally - proof that it's definitely worked is that your laptop should run quieter and better. If you want to give it a good workout, I would recommend downloading and running some Cosmology@home tasks.<br />
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You can see with all CPUs running at 100%, the cores are at a max. of 68C which is fine. <br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi5VQmf7K3y95JEGL3zVVWhCs-F9NLxeDwZytvXk1AnDzUEt5EjHiHzt4bYdQVwO-E4sSdmZGqtP4QDHMpIzJWDj_Xw8-IbQgB2kfCGfbVtPmJHagOk_i4QQtdZBEjQbYZf9j7B/s1600/Stress+test.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi5VQmf7K3y95JEGL3zVVWhCs-F9NLxeDwZytvXk1AnDzUEt5EjHiHzt4bYdQVwO-E4sSdmZGqtP4QDHMpIzJWDj_Xw8-IbQgB2kfCGfbVtPmJHagOk_i4QQtdZBEjQbYZf9j7B/s640/Stress+test.png" width="640" /></a></div>
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tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com0tag:blogger.com,1999:blog-19033682.post-57702062565892017642008-12-14T16:46:00.011+00:002008-12-14T18:11:22.476+00:00SATA drives and Acer T135More on the SATA / Acer T135 saga.<br /><br />Having got the PC to "see" the drive in the BIOS, it should be a simple matter of restoring the system volume onto this drive (or cloning it from the old drive), making it a primary, active partition (so it's bootable into Windows), and off we go, yes?<br /><br />So I created 1 large partition for the system and restored onto it. Did this work? No. Not in these Acer machines.<br /><br />According to boot.ini (which the wonderful StorageCraft ShadowProtect software can read easily), partition 2 was set as the boot volume. And I only had 1 partition - so better change it.<br />So I edited it to be partition 1, and tried again. No luck.<br /><br />I recall that the machine was supplied with the drive having two partitions -<br /><ul><li>Partition 1, around 2.8 Gbytes, for automatic 'recovery' of the machine</li><li>Parition 2, the usual Windows system volume.</li></ul>The recovery process is an Acer thing. Basically on boot, you hold down a key (Alt+F10) and the machine goes into auto-recovery mode. This basically re-initialises the system partition (2) from a factory-created archive held on partition 1. That's what the 2.8 Gbytes is used for. It provides a degree of safety for uses who trash up their machines so they won't boot, and I suppose it's cheaper than supplying Windows installation media.<br /><br />I'm not a great fan of this kind of auto-recovery (after all, it will trash all your programs and data, for sake of getting Windows re-installed). I prefer to use StorageCraft ShadowProtect with an external USB drive, as then I can get the machine back exactly to "how it was" the last time backed up.<br /><br />Out of a mix of desperation and curiosity, I tried holding down Alt+F10 as the machine booted (off the new disk, which did not have any recovery software on it, only a clean system image). Voila! it booted into Windows, off my new partition 1. So this told me two things:<br /><br /><ol><li>I could restore the machine, somehow.</li><li>The Acer BIOS somehow seems to be ignoring boot.ini, and doing its own thing, based on this Alt+F10 key (or lack of it).</li><li>The Alt+F10 key forces a boot from partition 1. It works, but it's a bit inconvenient for everyday use.</li></ol><br /><span style="font-weight: bold;">Another attempt</span><br /><br />Now knowing this about the Acer machine, I tried again, but this time<br /><ul><li>Small initial partition (around 2.8 GB), which I put a copy of the Acer restore stuff onto from the original disk</li><li>Large system partition (the rest of the disk) for Windows etc.<br /></li></ul>The first was copied from the original Acer-supplied hard disk. The second came from my ShadowProtect backup.<br /><br />Still no luck. It would not boot into Windows. But with Alt+F10 held down, it <span style="font-style: italic;">would</span> boot into the Acer Recovery software on Partition 1.<br /><span style="font-weight: bold;"><span style="font-weight: bold;"><span style="font-weight: bold;"><span style="font-weight: bold;"><br />Yet Another Attempt<br /></span></span></span></span>Finally, in desperation - I thought - why not run this Acer recovery software, and at least see if it can make the machine (normally) bootable, off a freshly restored partition 2. So I let it restore, effectively over-writing partition 2 with its virgin install of Windows + the Acer utilities etc. that came with the machine. (No CD-ROMs are supplied as standard).<br /><br />This resulted in a machine that actually boots up (although missing a lot of stuff, obviously). So - here's the trick - that Acer Restore feature is actually <span style="font-style: italic;">necessary </span>for a machine rebuild - in a totally non-obvious way. boot.ini looked just the same, before and after the restore.<br /><br />I wonder what the Acer Restore does to the disk. It does some magic that is not obvious.<br /><br />So ... having proved that was possible, I then restored the ShadowProtect image back over partition 2. And that finally worked! I had a machine that booted normally, and had everything back where we wanted it.<br /><br />I still don't know why the machine is so fickle with its boot-up, and why it ignores Windows' own boot.ini.<br /><br />Conclusions<br /><ul><li>If you have an Acer T135, that 2.8G of "stuff" on the Restore partition is <span style="font-style: italic;">essential</span> to the continued use of the machine, if you replace hard disks. Don't just think that having valid Windows install media and a valid key will be enough to get you out of trouble.<br /></li><li>Acer T135 has its own boot control which ignores Windows.</li><li>Don't forget to jumper new SATA drives down to the older standard, if they can be detected.</li></ul>and finally<br /><ul><li>Don't buy machines with proprietary motherboards and BIOSs if you can help it! Sooner or later they will drive you mad.<span style="font-weight: bold;"></span></li></ul><span style="font-weight: bold;">Recommended tools<span style="font-weight: bold;"><span style="font-weight: bold;"> and parts for this kind of work:<br /></span></span></span><ul><li>Patience</li><li>Anti-static wrist strap</li><li>Screws for holding the new drive in</li><li>SATA cable (usually not supplied with 'OEM' drive packages)</li><li>Jumper (again, usually not supplied)</li><li>Tweezers for fitting the jumper</li><li>Partitioning / formatting / backup / restore software, such as Norton Ghost, Acronis TrueImage, Partition Magic. My personal favourite at the moment is <a href="http://www.storagecraft.com/">Shadowcraft StorageProtect 3.2</a> which works fast and well in my experience. It comes with a bootable CD-ROM image that means you can work with machines even when the hard disks are unbootable. Review of the software <a href="http://www.pcmag.com/article2/0,2817,2254465,00.asp">here</a><br /></li></ul><span style="font-weight: bold;"><span style="font-weight: bold;"><span style="font-weight: bold;"></span></span></span>tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com0tag:blogger.com,1999:blog-19033682.post-86036389767665101532008-12-07T00:29:00.012+00:002008-12-07T00:59:57.506+00:00Acer T135 with and new SATA drives - a snagJust came across a nasty little snag with SATA disk drives. I thought I'd write it up, in case you run into something similar.<br /><br />One of our family computers is an Acer Aspire T135, around 3 years old now. The 80GB hard drive is getting rather full and slow. Time for an upgrade. <br /><br /><span style="font-weight: bold;">Step 1 - check what the existing PC can do.</span><br />It has a spare SATA connection on the motherboard, so that seems like the best way to go.<br />There is plenty of space in the case for a new drive.<br />There is a spare SATA-compatible power connector (different to the old-style 4-pin Molex's) dangling in the case.<br />I'll need to get a new SATA data cable for the drive.<br /><br /><span style="font-weight: bold;">Step 2 - plan how to use the drive</span><br />My initial thought is to use the new drive for the OS and programs, and the old drive as scratch area and - if it makes things run faster - the windows swap file.<br /><br /><span style="font-weight: bold;">Step 3 - choose a drive</span><br />A quick look at drive specs etc. suggests a 500GB drive as the best price point at the moment (given that the machine does not have to handle huge amounts of data usually).<br /><br />A quick check on the Acer website suggests no particular compatibility requirements for second drives (then again, it doesn't really say a lot about their machines anyway).<br /><br />Western Digital do a nice looking "Green Power" model which claims to save power. As family PCs get left on all the time, that seems like a good idea.<br /><br />I got mine from Novatech as they are local (www.novatech.co.uk).<br /><br /><span style="font-weight: bold;">Step 4 - install the drive<br /></span>Short work with a screwdriver and the new drive was ready to run.<br />Boot up, check in the BIOS that the drive was recognised ... nothing, only the existing drive is found.<br /><br />I tried various things, including:<br /><ul><li>Swap the existing and new drive data cables</li><li>Swap the existing and new drive power cables</li><li>Try with another SATA drive I had available (an older 160GB Maxtor). <span style="font-weight: bold;">Ah-ha! That works!</span></li></ul>So why does the new drive not work?<br /><br /><span style="font-weight: bold;">Step 5 - fault-finding .. it's NOT the BIOS ...</span><br /><ul><li>Maybe the BIOS is too old to read 500GB disks. So I flashed the BIOS with a newer version, directly from Gigabyte's website, rather than from Acer's website. </li><li>The motherboard is a K8VM800. But it's labelled as the K8VM800MAE on the motherboard itself. Gigabyte list two versions - Rev. 1 and Rev. 2 - but nothing about the MAE. According to the chips fitted it's closest to Rev. 1. (looking at the Ethernet chip type).<br /></li><li>Incidentally, flashing BIOSs on computers like the Acer T135 that lack a floppy drive is somewhat time-consuming and troublesome. It hasa nice integrated flash card reader though ... so ... After a bit of Googling, and making a DOS-bootable disk on a Flash SD card, which worked fine on one of my other machines, I gave up, yanked a floppy drive out of another machine, and used that instead ...</li><li>It flashed OK (but with a warning message), and it ran the computer OK, but it kept giving checksum errors on startup. Not such a good idea. Revert back to the original BIOS (which I had kept).</li></ul><span style="font-weight: bold;">Step 6 - try another 500GB drive</span><br /><br />As it happens, I have a 500GB SATA drive (different brand - Samsung) in another machine. So - let's try that.<br />It works! So there isn't a capacity issue. Must be something weird with the drive.<br /><br /><span style="font-weight: bold;">Step 7 - has anyone else hit this before</span>?<br />After some tricky Googling to avoid the hundreds of old review articles on T135's, many that have a different spec, I found a forum that suggested that:<br /><br /><ul><li>SATA has different speeds - 150MB/sec and 300 MB/sec</li><li>While everything is supposed to auto-adjust, it might not</li></ul><br />A quick check on the drive manufacturer's website pulls up a datasheet, and -- guess what -- there are some jumpers to force the drive down to the slower speed.<br /><br /><a href="http://wdc.custhelp.com/cgi-bin/wdc.cfg/php/enduser/std_adp.php?p_faqid=1679" target="_blank">http://wdc.custhelp.com/cgi-<wbr>bin/wdc.cfg/php/enduser/std_<wbr>adp.php?p_faqid=1679</a><br /><br />It's that OPT1 jumper (pins 5-6 on the drive family I'm using).<br /><br />Now the BIOS sees the drive. But the original drive seems to be taking ages to boot up in to Windows (despite not being changed at all). More on this tomorrow.tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com3tag:blogger.com,1999:blog-19033682.post-1150986573629948372006-06-22T14:24:00.000+00:002006-11-16T00:14:02.161+00:00Happy Solstice (yeah, right).I received a "Happy Solstice" message from someone close to me. While wishing them no ill whatsoever, I felt like sharing my own thoughts on the matter.<br /><br /><p>As a fan of Western reductionist scientific principles I was drawn to musing on the possible reason why the sun might not 'rise'. I came up with:<br /><br />1. The sun stopped shining.<br /><br />2. A large, opaque extra-terrestrial object (such as an Arcturan Mega-Goat) suddenly parked its hairy ass somewhere between the Sun and Earth.<br /><br />3. The Earth stopped spinning.<br /><br />Other than that, well, yup, the Sun will generally rise as usual.<br /><br />On (1) - the bad news is, this will happen sooner or later. But there's probably a billion years to go. As the Sun runs out of hydrogen fuel and starts to consume heavier elements, the most popular scenario is that it will gradually expand and swallow all the inner planets (including Earth). Bummer.<br /><br />On (2) - many of your friends who have chemically prepared for the Solstice might worry about this. Goats are usually friendly, but are omnivores and have large appetites. I would recommend further research to establish whether goats prefer red planets to greeny bluey ones.<br /><br />On (3) - Newton's Laws suggest that if, for some reason, the earth did suddenly stop rotating (and therefore the Sun not rise one morning), you would most certainly know about it, even if you were in bed at the time:</p><ul><li>Earth rotates Eastwards (i.e. towards the "rising" sun) at approx. 1000 miles per hour at the Equator. About 600 miles per hour at European latitudes.</li><li>You are rotating at the same speed, snug in your bed.</li><li>Earth stops. (This is unlikely as it would require a huge force to be applied to something that's very large, very heavy, and basically 99% molten rock so quite squishy and hard to get hold of). A large meteorite might just do it.</li><li>You, your bed, your house, and everything else that's not tied down initially keeps on moving at 600 miles per hour to the East.</li></ul><p><br />This is likely to be quite noisy and uncomfortable, and so people would (briefly) wake up.<br /><br />You can therefore banish any lingering spiritual guilt you may feel if you are not standing in some damp field with other beardy weirdies, swaying and singing out of tune.<br /><br />I suggest that you pass this tip on to your earthy friends, so that they don't have to get out of bed each year specially just to check. On the other hand it's mostly harmless and probably quite good fun, and you might even get lucky afterwards ...<br /> </p>tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com0tag:blogger.com,1999:blog-19033682.post-1137778524387938732006-01-20T17:26:00.000+00:002006-11-16T00:14:02.086+00:00I've been playing about with KPL (Kids' Programming Language), my first little program is a Celestial Mechanics simulator - try it out <a href="http://www.thetucks.com/Orbits.php">here.</a>tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com0tag:blogger.com,1999:blog-19033682.post-1132163045094681282005-11-16T17:27:00.000+00:002006-11-16T00:14:01.996+00:00CaffeineHave a large RFI (Request for Information ) document to fill in answers to this week. Once the phone stops ringing I find that I can get 'into flow' and work more effectively on these things. But that needs strong and regular caffeine input.<br /><br />A couple of weeks ago I downloaded some cool software that generates 3D models of molecules. The idea was to encourage Hannah to learn a bit more about chemistry, although I played with it more than she did.<br /><br />Here's a caffeine molecule model. The software is free, and there are lots of models out there on the Internet as well. I'll post links to them shortly.tucksterhttp://www.blogger.com/profile/05669324134346545492noreply@blogger.com0