"Iain Churches" wrote in message
ti.fi...

"Keith G" wrote in message
...

"Iain Churches" wrote in message
i.fi...

"West" wrote


...AND better no pot at all, but if you must, use a step attenuator
with
quality resistors.


Hi West.

Better still, no preamp at all:-) With the addition of a stepped
attenuator, one can feed the CD player straight to the power amp.
Morgan Jones states: "No preamplifier is better than any
preamplifier!" I agree with that sentiment.


S'what I did with my 2A3 SET which is effectively a power amp with a
volume control - my thinking was that the 'pre' section could be a
nightmare for a beginner to get right (quiet) and that there are/were
any
number of 'ready-made' pre's that could be used if necessary, until such
time I built my own! It has worked so well without a pre I never got
round
to building one!

Yes. That's a very good solution. What is ther sense of a preamp
with excess gain which you need to attenuate? I like to have the
gain control at about 2 oclock for monitoring at a "healthy" level



Many take this a step further and add an input selector switch
as well as the SA to the power amp. This makes sense too.


Except that it eliminates the option of a 'single source direct' and
condemns the amp to possibly 'inescapable' crosstalk with the extra
internal wiring....


Never found that to be a problem, unless of course you switch
to other unused and open inputs. Once they are terminated,
one can get a fig of 85dB. If you need, you can use relay
input switching, with the unused inputs just looking into a dummy
load.

Cheers
Iain

Perhaps you don't need a dummy load at the unused inputs because there is no
load. Maybe the relay could short the unused inputs for greater noise
susceptibility.

west