Master volume vs Atenuator

[Chorch Cluni]

Hi all.
I guess I know how an atenuator works, so my question is how in real life does the master volume compare?.

I think a master volume pot works like, say, an EQ through the FX loop, so it can lower the level of a maxed out preamp into the power section, right?.

[J M Fahey]

The attenuator is the real thing, it is flat, sends to speaker an attenuated but accurate version of amp output but most important, it preserves power tube distortion which is warm and full.

Master volume does not, power amp works clean contributing little, all distortion you have is preamp distortion, thin and buzzy.

Besides, attenuator keeps power pentode distortion, MV keeps Triode distortion, very different.

[joecool85]

The attenuator is the real thing, it is flat, sends to speaker an attenuated but accurate version of amp output but most important, it preserves power tube distortion which is warm and full.

Master volume does not, power amp works clean contributing little, all distortion you have is preamp distortion, thin and buzzy.

Besides, attenuator keeps power pentode distortion, MV keeps Triode distortion, very different.

I would argue that on most solid state amps, the end result is very similar when comparing master volume to attenuator.  Like you said though, tubes are a different story where you can get significant (and pleasant) power amp distortion which you lose when you turn down a master volume.

The biggest difference conceptually is location in the circuit.  MV sits between preamp and power amp.  Attenuator sits between power amp and speaker.