Damn that's a steal. I went and checked one out somewhat locally (about an hour away). It was one of the best sounding amps I've ever heard, clean. But unfortunately the compression/drive or whatever did not seem to function properly so I passed on getting it. An hour later I get home and the guy texts me back saying he fixed the issue. I was too lazy to drive back there and get it. So for me, it's one of those "one that got away" amps.
Frequency knob is like a manual wah. Pretty interesting feature. The more you use the EQ (bass/midrange/treble), the more effect it has on the frequency knob. If all EQ is at noon, the frequency knob provides no perceptible change.
Just like a tube amp, when volume is cranked it really saturates the tone. I'd have to get the amp outside to crank the master. I think all the fauna in a few km around would run for their lives, not counting neighbors. Inside at 2, you can't hear a human voice.
If master is cranked and volume controlled, it is unbelievably clean AND loud, hence the Twin or Super Reverb comparisons I guess (I never played either).
I think you could dial ANY tone you'd want on this amp. I'll try to replicate the ones I like on my other amps, then I might start to feel how to work it out. It is so ... complete as an amp, I feel like it's the ultimate modeler.