Consider that Kadlecik is getting a fair amount of clipping in his signal before it ever reaches the power amp, so that kind of changes the scenario when it comes to doing the Jerry thing with the mostly clean signal into a gently clipped McIntosh. It's a different approach. Vic uses an extremely powerful amp, but also achieves some modeled clipping so that he doesn't depend on the power amp itself to help limit and smooth things. Jerry worked with around 250 to 300 watts, and took advantage of the fact that the power amp itself would put a limit on the peak power because of its inherent power limitations.
Basically, you really have to consider how you're going to put a cap on the pick attack spikes so you don't completely destroy your ears and also so you don't deliver an overly loud, overly clean signal that just sounds sterile, cold and boring. Whether you approach it like Kadlecik, which works very well for him and provides a nice smoothing and sustain, or if you want to go the Vic approach where the digital modeling device helps control this, or if you want the real Jerry thing where the power amp itself provides some of the rounding or smoothing, this will help you find the right amp. Maximum power of the amp is critical. You DON'T want an amp that's TOO powerful if you aren't going to find some means of smoothing things out before the signal reaches the amp.
For Mattson in DSO, he's using a VERY loud Bryston power amp, and it was simply brutal if pushed. Cold, ice-picky, harsh, sterile, and lifeless. TOO clean, too linear, just like any overly powerful amp with a clean guitar signal. So we designed a couple of clipping devices for him. One is a pedal that is a very clean and UN-EQ'd voicing with the ability to just barely clip or dial it up to get fairly dirty like the old '72 and earlier tube overdrive sound Jerry got when he pushed his tube amps. We also made Jeff a rack mounted clipping device that roughly (very roughly) emulates the type of clipping a McIntosh would do when it's power transistors reached their limits. That rack mounted clipping device is WAY in the prototype phase at the moment, but it works and it helps. It's just not there yet for my tastes. The combo of these two clippers is what's enabling Jeff to dig in and shave off the ice-picky top end and get a bit of sustain while using an overly powerful power amp. By the way, the pedal clipper is something I'll be making more of in the next few months. I'm kind of designing it for us here who need to find ways of achieving that mild natural clipping but without the tone and EQ changes that overdrive pedals often do. Stay posted for that.
I've been hearing positive reports about the newer Rocktron Velocity 300, but I can't personally vouch for it yet. I've heard that you can kind of bang on that amp and dig in nicely with it. You can't go wrong with a tube power amp, because they'll naturally do the musical limiting, clipping, and smoothing. A real mac, like an MC250 is ideal in my mind. They're generally fairly affordable, easily serviced by a decent amp tech, and provide 75 watts per channel (peak power), which should be plenty for most mortal eardrums when using JBL's.
... and it's just like any other day that's ever been...