Which balanced tube preamp matches simaudio w-5?

Just discovered how good my system sounds with a tube preamp. I bought a temporary fix to test the waters and I am very pleased. Only thing the resolution is not great, therefore am looking for something better. Anyone discover a good match for the w-5 amp.
Doesn't have to be tubes though it could be ss. But I prefer tubes.
I have the ARC Ref3 with my Simaudio W-6s.
Hevac1, you beat me to it.

I recommend the ARC Ref. 3 also. (The Ref. 5 is out now, and supposedly even better than the Ref. 3, but the price of a used Ref. 3 is around $5K, which I think is a real bargain.) The Ref. 3 is much better than either of the previous Ref. preamps put out by ARC, IMHO. (My friend has had all three in his system, and the 3 is the best by far.)
Calypso, just got one. Very nice combo.