What tube pre amp match up with a solid state amp

By the way, is there any simple way to test if XLR outputs are actually balanced without a boatload of test gear?

Wow thanks for all the info. Some of it went over my head but all very usefull
PETE

Wolfman; with the amp or preamp powered off, measure resistance between pins 1 and 3 with an Ohmmeter. If you see something less than 1 Ohm then the pins are tied together like Atmasphere says. If the meter reads open (infinity) then it must be a true balanced circuit.

My ML 433 and ARC LS27 are a great match. A used LS 27 should just fit within the top end of your price range.

Wolf, I bet your preamp is balanced. But like a lot of modern studio gear, the outputs are probably set up so that the non-inverting occurs between pin 2 and pin 1 (ground) while the inverting output occurs between pin 3 and pin 1.

How it *should* work to get cable immunity is that the signal occur between pin 2 and pin 3 while pin 1 is ignored and only used for shield. But today a large amount of studio gear ignores this grounding issue, thus you are hearing differences in cables in the studio. Trust me on this one- the reason the balanced line system came into existence was to solve that very problem. I can do into the history of it if you like; but in a nutshell what is happening is that if you hear differences in cables then the equipment does not support the standard.