Tube-based EQ Schematic (NOT a Baxandall) :-)

[NewYorkDave]

It will work around a single triode, but distortion will increase measurably as you boost, since the circuit is running out of feedback margin. Whether or not you'll notice or care is another matter entirely. :wink:

 

[VacuumVoodoo]

The main source of distortion in my circuit is the loading of each stage by the next one at max boost, the component values of the eq chains may need scaling to avoid this. However, for a guitar amp the distortion generated produces some interesting tonal effects as each stage distorts in a differrent frequency band.

In a more advanced version each triode is feeeds a cathode follower which takes care of the distortion caused by te loading. It however requiers double number of tubes.

This is the guitaramp incorporating the tube based split Baxandall EQ:

and here's the link to a series of pictures from the building of the amp:

http://www.fototime.com/inv/784BAC9136A4E2C

 

[NewYorkDave]

Nice-looking amp!