I play in a cover band that plays a lot of Grateful Dead. Generally speaking it's a modified Fender Twin preamp into a McIntosh solid state power amp and JBL E120 speakers. I use a Sarno Music Solutions Classic Twin Preamp (Brand Sarno makes awesome stuff, his Earth Drive overdrive is my all-time favorite effect pedal and plays well with the Kemper), a McIntosh MC2100, and Beyma Liberty 8 speakers (JBL E120 clones). My friend Ben made a profile of a similar rig that sounds better than my initial attempts at profiling my own rig (it's on the exchange - search JGarcia rig). I'm also a sucker for 60s and 70s Marshalls and it's been great having easy access to them on stage as weil as a buhzillion other killer amps. Here's a few clips using the Kemper:
Peggy-O
Here's my old rig to compare:
http://come%20together
Here's a 74 JTM
http://mr%20charlie
Even if you're not a Dead fan this is a great clean rig, cuts through in a mix and great with a bigger band, and a great clean pallet for effects.