Pls help !
I have build several versions of P3A and they where fine. I have now a +/- 42 volt version and it is oscillating very hard - 20 volt p/p probably in the Mhz area. All caps ara mounted but nothing helps. What to do ? the output is 2SC3281/2SA1302.
Btw, if i drive it hard (input 2v p/p) @ 1 Khz it stops oscillating and act OK.
I have build several versions of P3A and they where fine. I have now a +/- 42 volt version and it is oscillating very hard - 20 volt p/p probably in the Mhz area. All caps ara mounted but nothing helps. What to do ? the output is 2SC3281/2SA1302.
Btw, if i drive it hard (input 2v p/p) @ 1 Khz it stops oscillating and act OK.
Hi
Are you sure your output devices aren't fakes? The 2SC3281/2SA1302 parts you mention were discontinued some time ago. Check here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=5064
Are you sure your output devices aren't fakes? The 2SC3281/2SA1302 parts you mention were discontinued some time ago. Check here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=5064
Thanks for the advice, but still i think the design shoul work.
Can anyone explain ??
I am kind of desperate.
Can anyone explain ??
I am kind of desperate.

Have you contacted Rod Elliot about it? It does sound to me like those chips need to be replaced. I don't know about where you are, but here, Digikey has the new Toshiba chips for like $2 each. The 2sc5200 and the 1943? Cheap enough. Contact Rod Elliot and let us know what he says about it.
-Matthew K. Olson
-Matthew K. Olson
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