RMosack wrote:
As I read it, the Plexi was the "slightly more gain" and the TMB was the "much more gain" offering.
Both the sIII and the Plexi have the boost switch option. I tend to run them boosted all the time, but that's just me.
RMosack wrote:
From how it reads, I'm guessing that you can probably mod between sIII and TMB, but the Plexi is an entirely different animal altogether.
Actually they're all based on the generic 18W TMB design from 18watt.com So any one of them can be pretty much modded into any other version, with not much more than a few resistor and cap value changes.
RMosack wrote:
One factor that plays into my decision is that I want to avoid redundancy if at all possible. I figure I'll probably never, ever have need to build an actual 50 or 100 watt Plexi clone, but there's a small chance I could someday build a JTM45 clone (maybe...). The sIII seems to step on the JTM tones a bit (based on the literature).
It is JTM-45 like, in that it has more clean range than the other members of Trinity's 18W family. However they don't sound the same. There's a lot of significant differences between those two amps in terms of the power tubes (KT66 vs EL84/6V6), bias method (fixed vs cathode) and negative feedback (present or not).