I have taken many amps to Jens. He is, by far, the BEST amp technician I have come across in my 33 years of playing guitar. How do I know Jens knows his stuff?
I work for the US Gov with real rocket scientists, engineers (of all types) and people who are just plain genius. I can tell you, very few (read only 1 engineer that I have met) knows anything about tube technology and even that one engineer only knows basic tube theory. For comparison, tube amps are like a dead language that only few people know. Find a guy that knows GUITAR TUBE AMPS, can PLAY, and has an EAR, and you get Jens Kruse! BTW, I have opened up my amps and inspected the work… Jens' attention to detail and quality of work would qualify as MILSEC.