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December 02, 2023, 10:20:36 PM

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6v6 tube question.

Started by Fossilshark, June 19, 2016, 12:17:13 PM

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If you took the power amp section of the fender champ amp (just the single 6v6 tube) and put guitar input directly to the 6v6 (eliminating the preamp) would it hurt the tube or just sound crappy? I was wondering if there was a way i could test just the power amp section first so i know it works when i test it with the preamp.


I don't see it hurting the tube but you probably wouldn't hear much, if anything at all.

A guitar with humbuckers will put out a signal of about 100mV peak to peak and that's just on the initial attack. The amplitude quickly degrades as the string vibrates and the note decays. I would think you would need a few volts on the grid to get anything audible out the speaker and probably around 30Vpp to drive it to full volume. And that is, of course, exactly what preamps are for.

If you want to test a single amplifier stage, a signal generator of some sort is in order. If you have the cash, a bench-top function generator is your best bet. If you don't, you can build a rudimentary one (which, incidentally is exactly what I've been working on lately). Of course, if you go that way, you then have to test the signal generator circuit which requires an oscilloscope. So you have to spend money either way.


thanks! im sure ill figure out a way to test it. just didnt want to blow a tube or something


It is really pretty hard to hurt a tube.

If you want to test it, and the problem is no sound, then the simplest signal generator is a screwdriver.  Touch a small screwdriver or other metal thing to the tube grid pin.  If you then hear some hum, the tube is amplifying.