Champ 5F1 distortion box

[lowell]

I have an idea kickin' round in my head. I want to experiment w/ a power tube distortion box. My simplest idea is to build a 5F1 champ and use it w/ a Weber Mass motor and create a line out that I'll feed into a power amp or another amp's input. The reason for using the 5F1 is its simplicity and also the fact that it is single-ended as to maximize even-order harmonic distortion in the power amp.

My main question at this point is this: Is power tube distortion generally considered to be cutoff or grid current limiting? Maybe it's a bit of both? Does anyone see any problem with my idea in achieving cutoff or GCL? Do you think this is a good idea? Bad?

[lowell]

Just had another quick thought. The asymmetry of the clipping will be a great aspect... however this may be too smooth for what I'm after. Possibly a push-pull arrangement will allow for a MORE saturated sound. I could then theoretically imbalance the clipping on each side of the OT. Just a thought.

[imaradiostar]

Sounds like a neat idea. Why not make the plate, screen and bias voltages variable so that you can control the symmetry of the distortion?

I think a low wattage push-pull amp could be neat as well and may cover more sonic territory- tough to say. Why not build both?

jamie

[Regis]

Gar Gillies did that about 40 years ago with the Herzog.

[lowell]

Hmmm... interesting. It's funny, there are no filter caps in the schematic. Also of note is a non-reactive load and a solid state rectifier. I'll definitely be going w a 5y3 and reactive load. From what ive read a reactive load is a key component in the sound.... and obviously because one basic aspect of speakers is the 6-7k rolloff. Have you heard the herzog?

[TDS]

Gar Gillies did that about 40 years ago with the Herzog.

You can read about it here The CANADIAN DESIGN RESOURCE » Randy Bachman’s Herzog

You can hear it in action here: YouTube - American Woman The Guess Who 1970