Thanks!
Crunch: Sort of works similar to Harmonics in a sense. The lesser values to me give me more tube type tones where the higher values sort of give me less. In other firmwares, the Crunch really made pinch harms jump out using higher values. But if you went too high, your sound would choke out...almost like using too much noise gate. It behaves differently now to my ears. For example, the 800 mod I like defaults to 16%. I notice some of the dynamics, pinch harms and overall sound, seems more transistor using higher numbers. So I set all my crunch knobs on every amp to 0 because to me, they feel and sound more tubey.
Sag: the best way I can explain it is....the lower the number, the more your amp breathes and opens up. The higher the number, the tighter and more refined it gets. Almost like it is compressed in a good way. Like the harmonics knob, lower numbers give you a bit more mids and open-ness, higher numbers tighten and give you a little less warmth and you're a bit more restricted. There we go...that's a good way to explain it. The lower the sag number, the less restriction on the amp. The higher, the more it tightens up...almost like a governor on your car.
X-former knobs....though many, including Cliff, have spoke highly of this gem of an option, as much as I mess with it, I find myself always reverting back to the default values for any amp I mess with. I've tried all different configurations with all the X knobs. You can come up with some cool sounds, but nothing ever blows my doors off in my personal applications.
Yeah, that Zakk Wylde does the pinch type thing. I use them less and less these days. But they sound so much better when you have a tube amp or in our case, a properly modeled tube amp with a strong 12AX7 front end. Transistor sounds when you do that technique, don't have that "choke" sound that almost appears to hit you in the back of your throat. LOL!
It's an irritating effect...but it sure is fun when you can nail it at will. I kinda stole it from Eddie...as he is the only one I know that makes them "choke/scream" while they remain musical.