While it would be cool if Randall made modules to the specs that the Modders do, it would be somewhat difficult as many things affect tone... Guitar, wood used in the guitar, pickups, Preamp circuit (& the tubes used, poweramp circuit & the tubes used, speaker cabinet & the speakers used in that cabinet. Not to mention most of the tones we have to go by are mixed & likely multiple amps on recording.
I am not an amp snob & don't mean to imply others here are, but I can honestly tell you I have never heard an old 60s or 70s vintage Marshall in person and a strait signal Guitar to Amp to Cabinet. So for me the Plexi probably nails the tone I think of/hear for that particular amp/era. I have heard a JCM 800 stock, modded, & with a overdrive/boost pedal in front. I like the modded & boost pedal tones over the stock 800. SL+ comes really close if not dead on. Now if a module just doesn't quite do it, then have it modded to what you want/need. If you feel the SL+ is lacking some bass then have it modded to your liking.
Holy crap that seems like a rant. At any rate Randall has made my dream amps (modules)
Mr Scary (I love GL's tone on that instrumental)
SL+ - JCM800
Plexi - 70's Marshall tone
Tweed - '59 Bassman for clean
Eventually what I will enjoy with the MTS is being able to A/B various modules to see the differences. This is something that would be very difficult in both space & money. Obviously I need to get more modules to fix my Gear ***** Complex. :twisted: