Atma-Sphere MP-1MKII (used) or the MP-3MKII new, blows all others away. No I am not a dealer or friend, just alot of expierience with "tube" pre-amps. ARC, CJ, Melos,Joule, CAT,Audible. The Atma-Sphere rules. Make sure you hear a unit that is fully broken in to really evaluate it, I think that is why we don't hear more about the pre-amps. They take forever to break in but it is well worth the wait.