I'm currently using a Marshall JMP-1 & a MAKO MAK4 preamp with my live. Both direct into the live or through a loop return then back into the live. Coupling both with some Ownhammer IR's sounds really great as do the dedicated IR's of the live too. Even direct into my PA system without an actual tube power amp I can get a pretty decent tone. My band (hard rock/alternative rock) just tracked a majority of the rhythm guitar for our new EP with the JMP-1 and Mako by themselves with excellent results. They both sound massive together! I actually ended up preferring it a bit more to the tracking we did with my '78 JMP 2203 w/APC mod (my favorite amp).
Other preamps I've used with the live...
- Voodoo Labs preamp
- Mesa Boogie Rectifier preamp
- Bogner Fish Reissue
- Bogner Blue, Red, & Uberschall pedals
- Blackstar HT-DISTX
- Electrode SR-71 Blackbird
I only own a few if the above still, but it wasn't due to them sounding crappy. They all sounded great too. Just had to use my budget for tools that worked with my current project. I can't wait to try the Zerrer with my live!