How many dB are needed?

[H Chandler]

What is the range of voltage gain needed for a "typical passive " guitar signal to adequately drive the grids of a set of 6L6 power tubes in push-pull configuration.

[Bruce / Mission Amps]

Depending on the class of power tube operation and the actual bias of the power tubes... usually somewhere between 25vac to 60vac from grid to ground.
So do the math and start with 100mv of signal to the first stage and end up with 25vac to 60vac ... MATH

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I forgot to mention +6dB is twice the voltage gain.

[H Chandler]

I did the math

I get about 48-56 dB

Thanks.