Good concept for a tube driven dist. with 12AX7 amp attached

[sir_modulus]

You know, that SD-1 gives me a good idea. A small tube dist. combined with a small tube amp, for a little tube amp.

I have a bunch (and they're easy to get) of 6AV6 tubes (the triode in them is half of a 12AX7). These have a triode and a diode. You could make the preamp as follows: with two 6AV6 triode gain stages, but before that have an opamp, with two diodes (made of 1/2 of the 6AV6's), then the amp is a push pull with the two 12AX7 triodes (like a firefly).

so for those of you who couldn't follow (it's quite confusing really):
amp needs:
2 6AV6 (1 high mu triode and 1 diode)
1 12AX7 (twin high mu triodes)

You have an efffect first made of two tube diodes and an opamp (like a dist. 250+ with tubes).
Then you couple this to two triode gain stages (from the 6AV6's).
Then the output is a push pull with a 12AX7.

What do you guys think?

[Peter Snowberg]

The 12AX7 has a VERY high impedance that it wants to see so it's not anywhere near as good a driver as the AT7 or AU7. It's also not very powerful (1/8th as much current as a 12AT or AU). Transformers that work well with an AT7 or AU7 are more easily available too.

A 12AX7 will sink 1.2mA with a load of 62,500 ohms at 250V
A 12AT7 will sink 10mA with a load of 11,000 ohms at 250V
A 12AU7 will sink 10.5mA with a load of 7,700 ohms at 250V



I think it's a great idea!

I can't wait for the soundclips.