preamp design from 3mv to 1v

[nedhogan]

I need to amplify a signal from 3mv to 1v. I am wanting to do this with one 12ax7 tube. Is that possible? Cheers

[Wombaticus]

I need to amplify a signal from 3mv to 1v. I am wanting to do this with one 12ax7 tube. Is that possible? Cheers

Sure, you'll need to cascade ( or maybe you could cascode instead, would need to check) both halves of the tube to do it, but it's only a voltage gain of 333x. You can readily squeeze 3600x out of a typical 12AX7 cascade. One caution is that 3mV is small enough that you may need to give some thought to noise, depending on your application.

[Austin]

I have thought about trying to do this with solid state technology to trick my cars computer to run leaner or richer from the oxygen sensors signal. Sorry if this is too off topic for you guys, but there are plenty of guys out there that have no way of adjusting the fuel mix on there car, they could install a volume knob on the dash and let them run any mix they want. This is one of the reasons I started learning how amplifiers work, so I could actually do something like this. I have spent as many years learning the ways of cars as I have learning to play guitar. They are actually very similar but most gear heads have no idea how electronics work and that makes me kinda sad beause they are sometimes very intelligent. I am glad I have found you guys.

[Alan0354]

Yes, each half of 12AX7 can get gain of 60. The question is this is guitar amp, guitar give out way more than 3mV. What are you trying to do?

[Chuck H]

I'm guessing a reverb pan into an effects loop?