TDA8920BJ noise issues

icko · 9th July 2009, 09:23 PM

Hi lads

I've built a mixer + phase rotator + 2 low passfilter + linkwitz filter + gainstage + bridged subwoofer amp with TDA8920BJ. I have som problems with noise. I think the output noise seem fairly high but also sometimes there is some "screeching" noise sounds that is not related to when music is on.

Anyone built anything with TDA8920BJ with similar experiences? I have cruised around forum for hints but can't really find any obvious mistakes I've done. Maybe put the output inductors a little bit close. I bought the chips on ebay, i've searched but not found any complaints on fake TDA8920 IC's from ebay.

here are some pictures of the PCB and semi-assembled PBA.

http://img195.imageshack.us/i/bottomy.jpg/
http://img525.imageshack.us/i/topgee.jpg/
http://img22.imageshack.us/i/backboq.jpg/
http://img156.imageshack.us/i/frontdnf.jpg/
http://img11.imageshack.us/i/leftbqo.jpg/

icko · 12th July 2009, 07:56 PM

after listening further i noticed that the really loud noise starts to come in bursts after it has played around 15 minutes. before that, nothing...

I first believed it was due to thermal issues but the chip is not hot at all.

no one has any clue?

majestic phone · 9th April 2010, 06:35 PM

can you help me and send schematic and full circuit diagram

9th July 2009, 09:23 PM	#1
icko diyAudio Member Join Date: Sep 2008	TDA8920BJ noise issues Hi lads I've built a mixer + phase rotator + 2 low passfilter + linkwitz filter + gainstage + bridged subwoofer amp with TDA8920BJ. I have som problems with noise. I think the output noise seem fairly high but also sometimes there is some "screeching" noise sounds that is not related to when music is on. Anyone built anything with TDA8920BJ with similar experiences? I have cruised around forum for hints but can't really find any obvious mistakes I've done. Maybe put the output inductors a little bit close. I bought the chips on ebay, i've searched but not found any complaints on fake TDA8920 IC's from ebay. here are some pictures of the PCB and semi-assembled PBA. http://img195.imageshack.us/i/bottomy.jpg/ http://img525.imageshack.us/i/topgee.jpg/ http://img22.imageshack.us/i/backboq.jpg/ http://img156.imageshack.us/i/frontdnf.jpg/ http://img11.imageshack.us/i/leftbqo.jpg/

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12th July 2009, 07:56 PM	#2
icko diyAudio Member Join Date: Sep 2008	after listening further i noticed that the really loud noise starts to come in bursts after it has played around 15 minutes. before that, nothing... I first believed it was due to thermal issues but the chip is not hot at all. no one has any clue?

9th April 2010, 06:35 PM	#3
majestic phone diyAudio Member Join Date: Apr 2010	can you help me and send schematic and full circuit diagram