With respect to the 2-Channel "H," it is a solid amp that was stepping stone from the single-channel designs with which Doug Sewell had a made a name. It is definitely "Tweed" in design.
I posted a mod that I created for the amp after Experience 2012. People wanted a footswitch that had LEDs. Doug's LED footswitch was a first-order design, that is, it contained a battery that powered the LEDs. The problem is that the amp uses relays for switching. It is a very pure approach to switching, but the way that the jack is wired lacks the ability to power LEDs because all of the switches do is connect the negative terminal of each relay to V- on the relay supply (the 2-Channel Custom sends V+ and V- out the pedal using a DIN connector). My mod involved using two logic-level power MOSFETs to connect the V- terminal on the relays to V- on the relay power supply electronically, which freed the footswitch TRS jack up for rewiring. I tapped V+ on the relay power supply and connected it to the shield terminal on the TRS jack. V+ was sent out to the pedal. The switches then controlled LEDs that were wired in series between the switches on the footswitch and the gates on the MOSFETS. The beauty of the design is that the relay power supply supplies enough voltage to handle an LED forward drop and still have enough voltage to turn each logic-level MOSFET completely on. The LEDs operate in parallel with respect to the V+ voltage supply, so there is never more than one forward voltage drop between V+ and the gates of the MOSFETs.
