The speaker makes quite a bit of difference -- throw in something with a ceramic magnet and the sound is very different -- brighter, harder, crisper, etc. The AlNiCo breaks up sooner (necessary for a 5 watt amp that wants to overdrive the speaker) and is definitely how it was done a long time ago. The phase splitter is also in that camp. FWIW, I play a mid-70's Les Paul Custom and I like noisy sloppy warm midrangey guitar. This amp also has no feedback, so even with a different speaker it is not going to give that clean modern distortion sound. Sadly, I don't remember what the tone stack is -- it has one knob and was copied off some vintage Princeton, but I can't remember for the life of me which one. I'd place the sound somewhere in the range of Motorhead to Mudhoney to Smashing Pumpkins. Grungy. Tubes are a 12AX7, 2 EL84s, a rectifier ... I think (I really can't remember -- we built this thing a year and half ago) and maybe something else. I'll have to open it up to see for sure.