Re: from another forum anyone any idea whats broke ?


"Stewart Pinkerton" <stewart@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:ak0u42pe101f62k5oq092jiddmf8d5fvvs@xxxxxxxxxx
On Tue, 25 Apr 2006 10:04:49 +0100, "Keith G" <keith_g@xxxxxxxxxxxxx>
wrote:

Tell me summat. The (outrageous) little speakers it's feeding are stubborn
little barsterds at only 82 dB and the volume display**

http://www.apah69.dsl.pipex.com/show/display.JPG

reads -10 dB for *loud* - does this matter, being SS an' all...??

(Fit were valves you'd think you were out of the optimum operating
range....

Hi Keith,

One of the nice things about modern SS amps is that the 'optimum
operating point' is anywhare from the noise floor up to 90% of full
power, so as long as the little beastie isn't audibly clipping,
there's no problem. In fact, I have my own main system set up so that
the volume control is at -6dB at the clipping point for 0dB FS on my
CD player. Gives you much more control when playing quietly, as
opposed to so many lunatic mainstream amps where you can only use the
bottom quarter of the control. I guess there really are people so dumb
that they think an amp is more powerful if you get full output with
the volume control only a quarter up....

These days, at least as far as valve amps are concerned there is
no need, with the exception of RIAA, for high gain preamp stages.
I think that Morgan J got it right when he stated that an ideal
sensitivity for a valve power amp was 2V for full power, so
that a power amp with a stepped attenuator on it's grid can
be fed direct from a CD player. I followed his advice on my
50W push pull parallel power amplifier, which runs with the
gain control nicely between 1 and 3 o-clock.

He also said "No preamplifier is better than any preamplifier"
Clever people these Welshmen:-)

In these days of high level sources, pentode front ends are definitely
out of fashion:-)

Iain


.

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