Cambridge Audio A1 MK3 SE repair (TDA1514 chips burned)

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Yeah, you're absolutely right, I was too quick to comment. Found them at a local supplier for a little under 1€ a piece.

Any idea about the problems with the circuit. It seems as though these regulators and the TDA1514A:s where the original broken parts before I replaced anything. The capacitor blow surprised me last night, I should have got the polarity right from the markings on the board (the other caps where mounted the same way).
 
if the capacitors that popped were on the output side of the regulators, its possible the regulators have failed short circuit and so the capacitors got the full voltage across them. Bad news if so - that will have toasted the opamp chips.

I've now seen pictures of the inside of this amp. Ugh. I would say, save yourself a lot of hassle - use the case and transformer, and build your own amp in there. A Gainclone would fit nicely, and most likely sound better.
 
if the capacitors that popped were on the output side of the regulators, its possible the regulators have failed short circuit and so the capacitors got the full voltage across them. Bad news if so - that will have toasted the opamp chips.

The caps where on the power amp board, you can see them in the picture of the board.

I've now seen pictures of the inside of this amp. Ugh. I would say, save yourself a lot of hassle - use the case and transformer, and build your own amp in there. A Gainclone would fit nicely, and most likely sound better.

Yep, it's a simple amp indeed and I look at this positively anyways. The case and transformer and pots etc. where all free and get new use anyhow. It would be nice to just get this thing working, but I'll won't rob a bank to do it ;)

Maybe I'll buy the transistors and see if this could work. If not, I'll look at the Gainclone closer. :)
 
Just got one A1mk3 with a toasted transformer...
Can someone please tell me the voltage on the secondary of the tranny because it can not be 28/0/28 because there are no regulator for the opamps in the preamp.
The datasheet of the TDA1514A gives a max supply voltage of +/-30Vdc so the 28/0/28Vac would be way over the limit.
And the opamps (TL072) have a max supply of +/-18V
I would shoot at a 28 or 30VDC for the power supply with a 20/0/20 or 22/0/22 transformer.

Ric
 
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