For anyone looking for a low-cost way to make a sterile or hifi amp (or bass) sound warm and tubey, check this thing out. At low gain settings with the tone control turned off, the EHX Hot Tubes (nano) does a very convincing tube sound, rolling off the highs and adding a bit of compression without any real noticeable low end loss. Instant old-school "warmth" to any rig. I've seen just a little bit of talk of it here and there, particularly from Gregmon over in the Pedal Breeders thread, but I figured I'd dedicate a post to it for those interested. I read Greg compare it favorably to his Blue Tube, and would agree with that very much. You even get some nice harmonic content that often only comes with a real tube pedal. As he points out, the EQ control is nice on the Blue Tube, but the compact form factor and 9v of the Hot Tubes is a win. As on overdrive, it's just kind of okay. I would never recommend it as a "tube growl" pedal. With the drive dialed up it is very similar to what I've heard from the EQD Speaker Cranker. I'm not a huge fan of that farty way-overdriven tube thing, but if you like it, this one has it. Mostly I think it's a great, inexpensive way to add the old school tube sound to your arsenal.