How many gain stages til it chugs?

[rockhorst]

For what it's worth: I've experimented and built quite a lot of Wampler Plexi Drive clones (I have a PCB on sale for this actually, shameless plug) and when selecting/biasing transistors I find that I dislike the sound when it's biased like the Fetzer Valve. To me, with J201s at least, I like 50% supply + 0.5V better than the more asymmetric setting that ROG suggests. Just my 2c. But use trimmers for the source resistors and you can easily experiment.

Also, referring to the topic title, what you call chug may well be a matter of EQ rather than gain (or at least in part). I'd suggest building a simple cascade of FETs and running it through a graphic EQ pedal like the MXR 10 band, see where the magic happen.

Lastly, to compensate for my own shameless plug, have a look at Jubal's new project here. It's called the Cascadia, you can guess why