Hudson Electronics Sidecar

 A TS with bandaxall tonestack, a germanium transistor wired as a clipping diode and a high fidelity op amp. Schematic is avaiable HERE.

Lovetone Brown Source

 There has been several schematics of this one over the years, each one having some bugs. But recentrly Lacesensor at FSB managed to do a proper trace and he posted thr corretions at FSB.