It's a terrific amp indeed. The best tubes I've used so far on the Glass are Mullard ECC32, which are expensive tubes. The gain on the ECC32 is higher, which also helps with the HE-6. Other tubes that work very well with the HE-6 are the 6SN7W Short Bottle. If you want cheaper nice quality tubes which have a good sound stage but sound a bit more solid state, try the Hytron (Pre-CBS) 6SN7. They're terrific tubes for the price. For the settings, use this: http://www.head-fi.org/t/621189/new-cavalli-audio-liquid-glass-amplifier-fall-release/660#post_11372925 If you were closer to SF, you couldve come over and tried a lot of my tubes.