I had an original rev 1, I think 2003. Was an awesome head. Had a look around the internals. Was a modified sovtek mig-100h which was a jcm800 nodded for gain and 6l6.
The amp was capable of.many awesome tones however the choice for the tonestsck sweep potentiometers was not great. The amp would get SPIKEY when turning that thing up. Down at three o'clock though the amp had a low mid focus and could sound great. Swapped for s mercury transformer and like even more.
Krank got a bad name when the artist yep was posting fake reviews. Their credibility never recovered. The krankenstein sounded awful and that sealed the deal. The rest was limping along with new owners etc.
When I see the rev 1 go for $500 around whre I often.think about grabbing one. The build quality was excellent with component selection closely mirroring the SLO-100.
if it is an old one I say go.for it.