Are there advantages specifically to mic preamps that incorporate tubes,
perhaps by use of a remote-cutoff tube? Prevailing opinion on rec.audio.pro
is that there is nothing significant about a tube, it's the transformers
that are responsible for the attractive sound.

Robert Morein asked:


Are there advantages specifically to mic preamps that incorporate tubes,
perhaps by use of a remote-cutoff tube? Prevailing opinion on rec.audio.pro
is that there is nothing significant about a tube, it's the transformers
that are responsible for the attractive sound.


Remore cut-off penthodes are not very well suited for straight
amplification jobs, since they introduce mainly odd-harmonic
distortions.

Tube sound in general, doesn't exist.
One can adjust the circuit for deliberate coloration, or for very
linear amplification.
Especially for microphone signals, which are tiny compared to the grid
span of even a 12AX7.

However, tubes are (in general) more noisy, microphonic (!), while one
of the largest benefits, their relative immunity to overloading, isn't
much needed in this application.

The sound of transformers is a bit overrated, if you ask me.
It is possible to have flat bandwidth of 10Hz...100 kHz with
transformers, provided one uses them well.

Mic preamps that contain tubes these days do so for several reasons.
One of them is marketing (tubes sell), the other one is the ability to
dial in some distortion.

Despite being a tube buff, I'd never use tubes in a mic preamp myself.
Getting rid of the noise is almost an impossible task, at least for
me.

--

- Never argue with idiots, they drag you down their level and beat you with experience. -