Unfortunately I don’t know much. What I can tell you is he only did about 50 or so like mine that had an extra transformer that was custom made, including the original transformer that came in the amp. I texted mike a few times over the last year, very strange guy to talk to haha. Nice guy though, but didn’t get much info. He does remember doing my specific amp though he said. Said he did this one specifically in about 1995. It’s a purple JMP so it sticks out alittle Atleast, this was known as his “head from hell” mod. From what he said, he basically changed what he was doing over time and went with the flow of what he was doing during a certain era. He said he did about 10 head from hell mods like mine, and he described it as “just what I was doing at the time, somewhat more compressed sounding, totally redone eq section” etc, I know, not much to say haha. It has 2 additional preamp tubes and all tube effects loop as well.