Ken Fischer was a character, and great amp builder. Bob and Ken communicated a lot regarding their amp designs. Bob shares some correspondence and pictures Kenny drew.
Bob plays a bit of bottleneck slide guitar, and discusses his early musical influences, Robert Johnson, Muddy Waters, Johnny Winters, Hendrix, etc... guitar amp building, shares his experiences regarding his 23 year friendship with Ken Fischer (and his Trainwreck amplifiers), personal insights into Ken and his philosophy on guitar tone, ends abruptly, (sorry, the cell phone cut off...)
Bob Gjika was friends with Ken Fischer (Trainwreck Circuits) for 23 years, up until the time of his death, and knew him about as well as anyone did, as they discussed their guitar amp designs and shared notes on how to solve different issues they encountered.
One of those things was the voltages necessary to run the amps properly. This video discusses this topic in detail.