The Steel Guitar Forum

I just got a '65 reissue Super Reverb and started playing through it. I've noticed that every volume pedal I try through it (Emmons original, Goodrich, and two Ernie Balls)doesn't respond the same way it does through a solid state amp like a Steelaire. The taper "moves" on the Tube amp such that I have to push the volume pedal farther down to get it to behave the same way it does on a SS amp (the taper is higher up, closer to the "off" foot position.

Is this inherent in tube amps?

Without knowing specific pot or input impedance values-- it's reasonable to think that the Steelaire has a wildly high input z, the tube amp would be something lower lower, and this could affect the way the volume pot reacts.

While the input impedance would make a difference, I suspect that most of the difference you're experiencing is in the pre and post gain differences (read: capabilities) of the amps. More total or preamp gain from one vs. the other means you're having to use less volume pedal to attain the same sound output.

Tab Tabscott wrote: Is this inherent in tube amps?

Yes it is. Tubes compress the signal in a way that solid state circuitry does not.

I've experienced the same thing you have when switching between solid state and tube amps. You have to goose the volume pedal slightly more on a tube amp to get to a given output level. It's especially noticeable when you're toward the top end of the pedal and pushing the amp hard... you're moving the pedal but not hearing the volume go up very much. Nature of the beast.

Tucker Jackson wrote:

Tab Tabscott wrote: Is this inherent in tube amps?

Yes it is. Tubes compress the signal in a way that solid state circuitry does not.

I've experienced the same thing you have when switching between solid state and tube amps. You have to goose the volume pedal slightly more on a tube amp to get to a given output level. It's especially noticeable when you're toward the top end of the pedal and pushing the amp hard... you're moving the pedal but not hearing the volume go up very much. Nature of the beast.

...in much the same way as putting a Solid-State rectifier in a '59 RI Fender Tweed
Bassman jacks the output by almost 10%..... .....but then, that's sacrilege...right?

Except that a mere 10% increase in power or volume would not likely be noticeable. However, the lack of sag or compression might be!