Re: [ARSCLIST] (dream) restoration phono preamp opinions wanted

[Don Cox <doncox@xxxxxxxxxxxxxx>]

On 09/04/07, Steven C. Barr(x) wrote:


> The point is here...that if both tube hardware and solid-state
> hardware can produce essentially-undistorted amplified version of
> sound-signal input, why should there be any reason to choose one or
> the other?
> 
> As a user of intentionally-distorted tube amplifiers (for harmonica
> playing)...I know that vacuum-tube hardware offers a much more
> endurable version of distortion than does its solid-state equivalent.
> However, if we design amplifiers of either sort so as to produce
> effectively undistorted output...there should be no audible difference
> between the two. At this point, it becomes more a question of
> nostalgia... the same thing that inspires me to seek out 78's of
> performance for which I already own master-pressing reissue discs!

I think the answer is that driving loudspeakers without distortion
requires several dB more power than people like to think - depending of
course on the efficiency of the speakers. Without that headroom,
distortion does start to set in at loud (but not excessive) sound
levels.

You are trying to get the cones to follow _exactly_ the waveform
received at the microphone. Cones don't want to do that. The films used
in electrostatics are a bit more willing, but not much. The air doesn't
want to be shoved around, either.

The manufacturers graphs (if they deign to give any) show distortion and
frequency response at low levels, not at the maximum output of the
amplifier.

Speakers made in the 1960s tend to be much more efficient than recent
ones.

Regards
-- 
Don Cox
doncox@xxxxxxxxxxxxxx