Could anybody recommend a good preamp (tube or solid state) that would give me the capability to get nice saturation/distortion. I've got the bluetube, but the tube seems to have died. Turning up the tube drive doesn't affect the signal. I'm into a lot of 50s, 60s, 70s stuff. Want something that would give me some nice, warm distortion, if I want it. At this point, my budget is in the $500 - $1000 range.