Clips ... well yes and no.
http://prophetsandpoets.com/josh/files/ ... et_mix.mp3
That's it with the .002uF/150K resistor combo (too bright), and the cut control in it. The PR is the lead guitar in the last 15 sec (the rest of the guitars are thru a GDS 18W combo). With the extra .001uF in there and the 100K res before the clipping stage, it sounds better... not so "hard" and "aggressive". In this clip the cut control was on about "5". Without the cut control, and with the .003uF/100K mod the amp has a more open and detailed top end, while not being overwhelmingly bright or strident. I'm going to take it to a blues jam this week and work it out on stage, then probably taste-test some preamp tubes before bringing it back to the studio to cut some tracks and maybe get more clips.
As far as the split-load PI etc... Well of course the split-load PI sounds a lot different than a long-tailed PI especially if you are getting a lot of PI or power-stage distortion but I am not sure that really affects the TW tone nearly as much as that clipping stage does, particularly when the amp is not flat-out dimed. If you run this amp on 10 you are nuts.
I was drawing some influence from the Express preamp just to give me some ideas, but I wasn't trying to make a wreck clone. There were a lot of elements of the PR that I really liked and didn't want to change like the way the power supply sags and gives it a kind of "chewy" or "spongy" feel when cranked, and the overall power-tube saturation feel but mostly I wanted a more balanced distortion/lead tone in terms of not overwhelming the preamp stages with bottom end like a regular Fender preamp does.
I kind of think this amp is much of a hybrid type amp. Express-type preamp coupled with a Princeton PI/output with no negative feedback, in an open-back combo. It's definitely unique!