I use the Xotic RC booster but I play primarily blues and hate fuzz boxes. There are too many other options to name–read on:

The keys are, in my estimation, great transparent tone with a smooth drive, bass and treble controls (almost essential unless you’re awfully lucky) and small size so both units–preamp and 44–can be mounted side-by-side on a 6″ X 6″ “pedal board”. After all, the point of the Magnum 44 is tiny size/light weight. So, my friend, any pedal will work as a preamp since they all have some sort of pre-amp built in.

Magic Frank

I’ve used the EHX tube pedals as pre-amps quite a bit when i gig with my Sunn Concert Slave. I particularly like the “Hot Tubes” and the LPB-2, and I just got the “TubeEQ” which sounded promising in the store.

The pedals are big, which may defeat the “portable rig” purpose fmalitz mentioned, but they sure sound good!

Well, if you’re ever in Eugene, OR…

I’ve heard really good things about the Jekyll and Hyde!

I use this. It works really well.
I might stick a distortion box in between so I don’t have to use amp models for that.
Very cool portable amp that can DI as well.

[img]http://mysite.verizon.net/vzezbpai/sitebuildercontent/sitebuilderpictures/PortSetup.JPG[/img]