I have watched a few comparisons between the Fender 57' Tweed Champ and the new Vibro Champ Reverb. Honestly, without reverb or tremolo, I prefer the tweed clean tone. And that got me thinking. The tweed has no tone knob. I have owned both a Gries 5 and a Vox AC4HW. Both had the ability to bypass the tone stack. On the Gries, it was the middle control that once turned up all the way, somehow allowed the signal to bypass the tone stack. On the Vox, it was a "Hot/Cold" switch that did it. On both amps, I eventually played it that way 90% of the time because it sounded so good. On the Gries, all tone knobs maxed meant it was bypassed, so no way to compare. But on the Vox, the "hot" setting did not seem to me to be the same as turning both the bass and treble knobs all the way up. 1. Am I the only one who can hear the difference? In discussions about the VoxAC4 vs the AC4HW (or the AC15C1 vs AC15HW) I never hear this feature mentioned. 2. Why not more of these switches? Doesn't seem like an expensive addition. Allen amps offers this on most models. I'm wondering if the some of the Swart switches do the same. 3. Can one be added relatively easily to a PCB board amp (by a tech, not me)? 4. Do features like reverb or tremolo similarly reduce tone? 5. The AC15 normal channel seems to have no tone stack, is that essentially a channel that effectively does what I think it does? I know it is all complicated, but if anyone is willing to drop some knowledge, I'd appreciate it!