12AX7 - Reverb driver

[überfuzz]

I'm tinkering with a reverb driver that I build around a 12AX7 tube. My plan is to have a ~30 to 50 Kohm anode resistor and suitable cathode resistor guestimate 500 Ohm. This is to get the tube to drive a beefy current. Now my question, are there any big NO-NOs I should be aware of?

I think it's called bias point in English. I figure I'll try something like this: Load Line 12AX7.pdf

[g1]

Have you looked at other amps that use 12AX7 as reverb driver? Traynor YGM3 comes to mind, probably many others.

[überfuzz]

g1 - No I have not... I think I'll try the set up in the pdf I attached. I wanted to know if I break any, lets call it, good practice. For instance, the power dissipation at idle is roughly 33% of max.

[g1]

Here's the one I mentioned, I think your values are similar, not sure about what kind of plate voltage you are considering.

[Gregg]

Mesa reverbs are all 12AX7 driven with the "regular" Fender type OT so it's a good idea to check their schematics. If you don't feel like using an OT then maybe a MOSFET follower would be a good idea.

[überfuzz]

I tried a low gain driver stage pushing signal into the reverb tank. The 'pick up' stage is a high gain stage, well fairly high gain. This seems to work quite okay, might tinker a bit more to get more reverb signal

[g1]

Are you transformer or cap coupled into the tank?

[überfuzz]

Are you transformer or cap coupled into the tank?

It's transformer-less. Cap coupled into tank. At the moment I'm tinkering with a filter that is placed on the tank output. I simply unhooked it, however, I can't seem to get any affect there.

[g1]

What is the tank input impedance? F type? I think F is the highest, so least current drive required.

[überfuzz]

What is the tank input impedance? F type? I think F is the highest, so least current drive required.

Its actually a G typ.

Impedance in Ohms
IN: 8333 and 735 dc
OUT: 2575 and 200 dc

[g1]

Well that's even better. I did not even know there were "G" input impedance tanks. Learn something new every day .