Tube preamp signal amplitude?

[DonMoose]

So, what sort of signal amplitude do we have hitting the pots in a tube preamp? I mean, GND to the local B+ would be the theoretical max, but in reality are we looking at more like 10 or more like 100?

[surfsup]

Which pot? The MV pot before the poweramp? or the TMB? Gain pot?

It depends. Obviously the MV pot will be somewhat, or slightly more, than what it takes to drive the type of power tube used in that amp. The type of amp design matters here too. Clean amp? distortion generated in the PA?

If the gain pot, probably not much more than double the signal the next stage would likely want to see before it is heavily distorted. And "heavily" is an arbitrary statement here that means different stuff to everyone.

And, all this is affected by the amplitude of the input signal as well, and what the guitar volume pot is set at.

[tubeswell]

Maybe 0.5VAC in V1 for a single coil p'up, or maybe 4VAC max for a beefed up humbucker - use your gain stages' gain and interstage impedance bridging to figure out what is happening after that.

[DonMoose]

Let's say the TMBV in a cathode-follower type toplogy running dimed with humbuckers and an overdrive pedal.

[surfsup]

That signal (CF->TMB) would be less than the input since the CF has gain<1 and the TMB will attenuate the signal to around 1/10th so you're looking at a signal peak of the input peak*0.1-ish

your question doesn't indicate what stage or stages are before the CF, how much overdrive the OD pedal produces, or what's after the TMB.