The Big Max is a killer amp. I've been low key looking for another one now that I am working again
The best way to think of it is: "...if Peter Diezel made his version of a Marshall 2204." It's the most Marshall-y sounding Diezel I've played, but it does its own thing, too. It's far thicker, bigger, chunkier, gainier, and darker than a 2204. That said, the bright switch is a nice touch and can give you some of the "kerrang" back. There is a surprising amount of gain on tap (especially with higher output pickups), far more than a stock 2204 and at lower volume levels. Speaking of which, the master is excellent and this amp can easily be used at home. The real feature here, though, is how well this amp takes pedals, and I'm not talking about into the low-gain input. If you throw a Plumes or modded 808 into the high-gain channel, watch out. It gets very gainy and aggressive very quickly, especially if you turn the bright switch on and keep the amp's gain a little lower (adjust Presence and Depth to taste). Another fun thing to do is throw a fuzz in front of it for those Pumpkins tones.
It's just an all-around awesome amp that more should people should check out. In fact, Mike from Omega Ampworks told me that he thinks it's the best circuit Peter Diezel has made since the VH4.
You can check out the video below. It's one of my older videos so it's just an iPhone in a room with no post-production of any kind, but it's representative of the sound and the stuff I talk about is on point.