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Old October 25th 04, 07:36 AM posted to uk.rec.audio
Rob
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Posts: 127
Default Couple of amplifier Qs


"Keith G" wrote in message
...

"Rob" wrote in message
...
Hi - I wonder if anyone can shed some light on the operation of a Hitachi
HMA 7500 mk2 pre/power amp:

1. It can connect through two in/outputs - direct and 'condenser
coupling'. Anyone any idea what this coupling thing is?

2. There's a switch on the front of the power amp labelled 'BLT' - when
it's switched in the speakers switch off. 'BLT' is also marked on the LH
direct input on the power amp, and the meters have a range marked BLT, at
double the watt markings of a scale beneath. Any idea what that's all
about (apart from sandwiches)?

3. 1 side of the power amp gets very hot directly above the heatsink -
the RHS on this photo:
http://tinyurl.com/5eqne

I realise this is close to the transformers, but the heat is very local
and *very* hot - probably hotter than the casing of a class A valve amp.
The LHS is warmish, more your tepid warm. I've had a nose about inside
and I can't see anything obviously fried or about to fry, and I've tried
switching the inputs and speakers around - same result.




Drop this mutha in the skip where it belongs and put another record on
instead! ;-)

:-)

It would actually *make* a good skip, it's flippinnormous. And with its 6
phono settings plenty of fiddlage ahead. Will it survive a tube shootout ...
tbc!

Rob