"TT" wrote in message
...

"Alan Rutlidge" wrote
in message
...
:

:
: Apologies guys, I haven't been following this thread
closely but just out of
: curiosity is the amplifier (JT's) referred to by TT a
Robertson Audio Forty
: Ten?
:
: Cheers,
: Alan
:
It's the heavily modified one I sent you the pics of ;-) JT
will be able to give you more details on it.

Cheers TT


Thanks TT.

I suspected this is the one you were referring to.
Not wishing to get up anyone's nose but the quality of the internal
construction of this amplifier leaves a lot to be desired. It kind of
reminded me of my first efforts with a soldering iron as a school aged
teenager, having never at the time been showed how to solder properly.
I do find it a bit difficult to accept this is actually a commercial
product, albeit a modified one. Point to point wiring on tag strips (with
the exception of the two small PCBs with the ICs etc) would be considered
more the exception rather than the rule in a solid state design.

Just re-examining the photos of the internals I think the hum problem may be
traced back to what looks like IMHO an obvious dry joint on the -ve terminal
on one of the ELNA can type smoothing capacitors. Also (but just guessing
here as photos are quite often hard to get "the full picture" from) the
earthing structure might be a bit "messy".

Cheers,
Alan