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
So as I continue to hunt for the pres recommended in this thread, I've been thinking (always dangerous) about going with a tubed unit. Any thoughts on the Parasound Halo A21 with either an Audible Illusions Modulus 3A (used) or a PrimaLuna Prologue Three (new)? In both cases, I'd be sacrificing a remote, but I might be willing to do it if the sonic rewards are there.
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