I kinda had a breakthrough lately figuring out what exactly is going on with these tones. It isn't so much about preamp vs. power amp distortion like I previously thought.
It has very much to do with setting EQ curve before and after the preamp and/or distortion pedal. One thing that was tricking me was that the tone sounded so incredibly trebly to me that I wasn't realizing just how strong it is in the low-mids and bass. There really is a lot of percussive "thump" which comes somewhat from compression, and a lot from having strong, clean bass present. However, if you run too much bass and low mids before the preamp or distortion pedal, you get too much really hard-clipped "heavy" distortion. You don't have to cut a LOT, but just a little scoop out of the low mid frequencies before the preamp. I leave 100hz flat and scoop between 100 and 500 hz. Then you jack the sh*t out of everything above 1khz. Max it out, +15 db or whatever your EQ pedal goes to. When this hits the preamp and/or distortion pedals, super high frequency harmonics are produced and that is what creates the jangly awesomeness characteristic of his tones. Now the sound will be a bit unbalanced coming out of the preamp, so after this so you have to even it out with the amp's EQ and "add back it" enough bass to give the tone the punch and authority. Run the bass on the amp as high as possible without causing the amp to start distorting the bass frequencies. Mids probably somewhere around 5, too much and it will get too "thick" and lose clarity. With the treble, you'll want to dial it back. If you run it maxed (as I was doing in the past to try to get this tone), its going to be far too harsh since so much was added in before the preamp. So dial it back down to 6 or so.
The rest just comes down to some compression at the front end of the signal path, a phaser/flanger of some sort to wierd things up a bit, a distortion pedal placed just after the intial EQ (before the preamp) for dirtier sounds, and some balance of slap delay and reverb.
Try it out!