SymAsym - "The Sequel", AAK's Rev_1.4 PCB Builders Thread - Page 11

coolnose · 4th November 2011, 02:28 PM

The amp is running fine for a couple of days now, getting pretty warm though.

No turn-on thumb or whatsoever.

The only annoying thing is the crackling sound from the speakers as the caps of the amp discharge on turn of.

I used the search function but could not find some having build a simple relay-solution for shorting the outputs on turn-off.

I don't wat to go for the Velleman solution as I need 4 of them and the price tag is a bit high, at least for me.

Any hints ?

AndrewT · 6th November 2011, 02:11 PM

Start with a manual input mute and see if that makes a difference at shutdown.

Just short all the signal inputs to their respective signal returns. Power ON, warm it up. Power OFF. Any improvement?

Ed LaFontaine · 12th November 2011, 02:32 PM

Al,

The package with boards and other goodies arrived today. Thanks

johngalt47 · 18th March 2012, 09:34 PM

Where is the BOM for this board?

Ed LaFontaine · 19th March 2012, 12:15 AM

Latest one I have found:

http://www.diyaudio.com/forums/attac...ev_1.3_bom.pdf

pinkmouse · 19th March 2012, 12:24 AM

Here you go:

AAK · 19th March 2012, 01:27 PM

Hey Guys,

Al's attached BOM is the correct one for Rev_1.4. Ed, the BOM you attached is for Rev_1.3.

Best Regards,

Al

SteveA · 26th May 2012, 02:51 AM

I bought 6 (and rec'd 12) of the version 1.3 amp quite some time ago. I have now returned to the project having completed all the boards(except for output transistors on 4) I have tested the 8 boards which are complete (complete with dim bulb tester).

The bad news is 3 failed the smoke test. The somewhat better news is that the other 5 all passed the smoke test (all 8 board display the correct rail voltages of +/- 52.3 V which is inline with noload conditions for a 35-0-35 transformer I'm using). Testing the 5 boards with the 100R safety resister inplace I measured voltage drops accross this resistor ranging from 1.4V tp 1.7V. The assembly manual for version 1.4 indicates this drop should be 2.5-3.5V. Should the voltage drop for version 1.3 be the same or, if not, what should it be (and do I have an issue with the 5 smoke free boards)?

Thanks,
SteveA

6th November 2011, 02:11 PM	#102
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Start with a manual input mute and see if that makes a difference at shutdown. Just short all the signal inputs to their respective signal returns. Power ON, warm it up. Power OFF. Any improvement? __________________ regards Andrew T.

12th November 2011, 02:32 PM	#103
Ed LaFontaine ...truth seeker... diyAudio Member Join Date: Feb 2004 Location: where the Appalachians rise from the Blue Grass	Al, The package with boards and other goodies arrived today. Thanks __________________ ...call me Ed...Special Ed... EnABL kit http://www.diyaudio.com/forums/swap-meet/119852-enabl-kit.html DCB1 parts http://www.diyaudio.com/forums/swap-...ml#post2361098

18th March 2012, 09:34 PM	#104
johngalt47 diyAudio Member Join Date: Mar 2004 Location: Texas	Where is the BOM for this board? __________________ Any technology sufficiently advanced is indistinguishable from magic

19th March 2012, 12:15 AM	#105
Ed LaFontaine ...truth seeker... diyAudio Member Join Date: Feb 2004 Location: where the Appalachians rise from the Blue Grass	Latest one I have found: http://www.diyaudio.com/forums/attac...ev_1.3_bom.pdf __________________ ...call me Ed...Special Ed... EnABL kit http://www.diyaudio.com/forums/swap-meet/119852-enabl-kit.html DCB1 parts http://www.diyaudio.com/forums/swap-...ml#post2361098

19th March 2012, 01:27 PM	#107
AAK diyAudio Member Join Date: Jul 2004 Location: Florida	Hey Guys, Al's attached BOM is the correct one for Rev_1.4. Ed, the BOM you attached is for Rev_1.3. Best Regards, Al __________________ Love when you can, Cry when you have to, be who you must, that's part of the plan.


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4th November 2011, 02:28 PM	#101
coolnose diyAudio Member Join Date: Sep 2009	The amp is running fine for a couple of days now, getting pretty warm though. No turn-on thumb or whatsoever. The only annoying thing is the crackling sound from the speakers as the caps of the amp discharge on turn of. I used the search function but could not find some having build a simple relay-solution for shorting the outputs on turn-off. I don't wat to go for the Velleman solution as I need 4 of them and the price tag is a bit high, at least for me. Any hints ?

26th May 2012, 02:51 AM	#108
SteveA diyAudio Member Join Date: Dec 2001 Location: St Paul, MN	Version 1.3 questions I bought 6 (and rec'd 12) of the version 1.3 amp quite some time ago. I have now returned to the project having completed all the boards(except for output transistors on 4) I have tested the 8 boards which are complete (complete with dim bulb tester). The bad news is 3 failed the smoke test. The somewhat better news is that the other 5 all passed the smoke test (all 8 board display the correct rail voltages of +/- 52.3 V which is inline with noload conditions for a 35-0-35 transformer I'm using). Testing the 5 boards with the 100R safety resister inplace I measured voltage drops accross this resistor ranging from 1.4V tp 1.7V. The assembly manual for version 1.4 indicates this drop should be 2.5-3.5V. Should the voltage drop for version 1.3 be the same or, if not, what should it be (and do I have an issue with the 5 smoke free boards)? Thanks, SteveA

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