Options for preamp?

[nwsteen]

Gents,

I'm considering ordering a z.vex imp amp (the microscopic stereo tube amp) for my desktop, and I'd like to be able to run my guitar through it. I'm taking it as an opportunity to get back into pedal building, and maybe even experiment a little bit. I've got 3x fatpants jr. boards laying around, as well as a flabulanche. I've got the klon booster board as well (I forget the name, sparkle bomb or something). I've also got a Mythical OD laying around as well as a (1) Prince of tone modified bluesbreaker (2) Rullywow queen of bone (3) whatever that bass / darker sounding madbean bluesbreaker circuit was running @ 18v (4) a few modified boss sd-1s and a few more pedals I'm forgetting.

I've been interested in the ROG Azbache and Umble circuits. Particularly the Azbache's use of diodes to prevent hard clipping of the jfets, and the Umble's unique pre-drive EQ circuit. I'd also like to run whatever preamp I do end up building at a higher voltage (minimum 18v but ideally I'd like to jerry rig one of the fatpants boards to run everything at ~22v). I guess one threshold question is - would running the 2n5457 in Q1 at a higher voltage drive the j201s in Q2-Q4 more?

Additionally, I built the 2013 fat pants way back when and I really enjoyed the 'fat' (a/k/a bias) knob in terms of how it functioned. Would it be possible to incorporate something similar into the Azbache? In addition to the Umble tone stack? Or am I duplicating the functionality of the bright and scoop switches? The guitar I'm using has p-rails pickups, so the bias knob really helped out in switching between single coils, p-90s, parallel (a/k/a PAF approximation) and series (hot humbucker sound).

I'm not looking for an accurate simulation of any one amp in particular. I'd just like a circuit that mimics the nonlinear response of a tube amp, with a good clean sound that has a little bit of that echoplex 'magic' sparkle and slight compression, and a clear driven tone. In my head that means the azbache @ 18-22v + the umble tone stack + the aquataur compression circuit. Fat/bias knob would be awesome but I don't know enough to know if I'd be duplicating the functionality the umble tone stack. Another consideration is that the bias control on the fat pants affected both the frequency response and the timbre of the final sound, vs. tone stacks I've traditionally used which changed the EQ but didn't really impact the timbre of the final sound. So, if I could keep both and change a cap to reduce the frequency overlap between the two I'd absolutely go that route.

Should I:
(1) build the modified azbache / umble I've described? And just experiment with a few caps / configurations before boxing it up?
(2) build one of the fatpants jr. boards -> umble tone stack -> the flabulanche instead? I've got a few mpf102s laying around so I could make the 'volume' control an internal control and just set it up at unity going into the flabulanche.
(3) stop overthinking it and just use one of the gazillion overdrive pedals I've already built as a preamp? And just run the output into the AMZ jfet splitter?

Any thoughts / comments are greatly appreciated. Hope everyone had a great new years!