Will Reeve wrote:

You can replace the TDB with the easier to find LM337.

Good - I thought it might be from the same family (137/337). I'll track down
some 337s.


It soulds like
a nasty short somehwere to blow the regulators or more likly giving
them a rather high voltage to try and regulate.

I thought of a short at first, but I think the regulators are supposed to
have short-circuit protection, so I'm wondering if it's a problem with the
supply voltage.


I would give the PSU
a good checking over before you blow another pair!

That's exactly what I'm going to do - desolder the transformer first and see
if it's putting out believable AC. Then work forward if that's okay. If the
transformer's busted, I suspect the amp will be scrap.


The op-amp would
require a +ve and -ve supply so probably died before the regulator
gave up!

The only thing I know about its demise is that one channel went dead - no
bangs, flashes or smoke, according to the mate who then owned it. I agree
that the op-amp would have to blow before the regulators. :-)


--
Wally
www.artbywally.com
www.wally.myby.co.uk