In article , mick
wrote:
http://www.milbert.com/

"Tubes Vs. Transistors - Is There An Audible Difference?"

I don't want to rerun the old "valve versus transistor" arguments, but
this caught my eye as it is from the point of view of a recording
engineer.

Apologies to those of you who have seen it before.

First saw this over a year ago. The paper basically reports on:

1) looking at low/no feedback amps when driven heavily into clipping.

2) It notes differences in the waveform/spectrum in clupping for different
amps/gain devices.

3) The implication is drawn that these differences mean differences in
sound.

The snags are;

1) The amps considered don't really have much in common with those used as
valve power amps. (Unless you assume that all valve amps behave and sound
the same irrespective of design or application.)

2) Ideally, you should not be clipping signals with your amplifiers at all
if your concern is hearing the input waveform rather than enjoying
clipping. I doubt/hope that the valve pre-amps some people use in domestic
audio are clipping like this in normal use. If they are, my recommendation
would be to change the preamp or the use to avoid this excessive and
unnecessary clipping. Given the high bias voltages available for such amps
I can't see clipping being difficult to avoid. Indeed, the designs I've
seen reviewed seem to be well clear of this problem.

3) No real evidence is presented that allows the actual evidence in the
paper to lead to a conclusion that valve amps sound 'better' as a result of
adding particular types of distortion.

Thus I'd say that all the (quite old, now) paper does is warn us that
clipping may affect the sound. I doubt anyone would find that surprising.
Nor do the circumstances of use in the paper seem directly relevant to
domestic audio.

Slainte,

Jim

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