I rewired My mk1 to have +/- Midi switchable just couple weeks ago, input sensitivity is great. but I like white panel rather than black, I think Herbert with white panel is the nicest looking of all diezel amps.
I just received a Mk1 herbert and I would love midi switching on the +/-, I also would like more sensitivity on the input, I find that it doesn't clean up very well with the guitar volume.
Can you give any more info on how you modded yours for both the +/- and input sensitivity?