Colin Stamp wrote:
Hi all,

A long long time ago, I made an amplifier using two of these modules.
Since I made it in my yoof, I'm quite attached to it. Recently though,
my wife bashed her head on the underside of the shelf it was on. There
followed loads of crackling from the speakers accompanied by the
disturbing hum of power rails coupled directly to speakers. I sprang up
and flew across the room to switch the amp off (which wasn't easy since
I had to be careful to avoid my wife who was now rolling around on the
floor, clutching her head) but I was too late and the left channel was
toast.

I'm a bit mystified as to how the head-bashing could have caused any
damage but, aside from that, repairs are progressing and new bits are on
order; I only lost two of the output transistors, some resistors and a
couple of polystyrene caps. The only problem I'm expecting is how to set
up the quiescent current, since I can't find the original instructions
for the modules.

how the **** did you lose polystyrenes?


I know it's a bit of a long shot, but does anyone here happen to have a
set of instructions hanging around? I think it was quite a popular
module for quite a long time. The order code was HQ68Y.


Don't have instructions, but there should be a trim pot pot somewhere.
Turn it so the current drawn (remove line fuse on the low voltage side
and meter across) is as low as you can get, the turn the pot up to give
5-10mA more than that.


Oh, and the wife's making a full recovery, by the way.

Cheers,

Colin.