Which used preamp for Halo A21, under $1,000?


Right now, I have an Anthem TLP-1 pre mated to a new Parasound A21. The combo sounds good, but I suspect that the Anthem may be the limiting factor to achieving "great." Suggestions?

Preamp: Anthem TLP-1
Amp: Parasound Halo A21
Disc player: Oppo BDP-105
Turntable: Beogram 8002
Speakers: Alon II
dbxdx5
Czarivey: Forgive me if this is a stupid question, but are there any balanced tube preamps?
As mentioned above, YS audio has tube balanced preamps:

http://www.ys-audio.com
The YS audio gear looks interesting, but I'd be more comfortable buying from an established brand (even if it's also made in China). Any other balanced tube preamps in this price range, used or new?
There are plenty of balanced tube preamps, but do you actually need one? Tubes have larger distortions noise and higher output impedance. Balanced solid state preamplification is prefered IMHO.