Preamp / Passive, for Biamp

[CR500]

Hi guys, a noobie calling.

Background:
I recently upgraded my speakers from my beloved ADS L1230 (will never sell them, except to make room for L1530) to some IRS Beta's. The Betas, of course, are biamped. I'm running a Crown PSA-1 on the woofers and NAD2200 on the panels. With the new speakers I've noticed that I never touch my bass / treble controls. Also, the NAD gear has TONS of unnecessary gain (amp and 1130 preamp). So I'm thinking about building a high quality preamp.

I know I'll need two sets of outputs, and one of them will need some gain to match the different amplifiers (I measured ~7dB difference between the two). Additional overall gain or passive is still in question (I like to crank up the quiet passages so I'm guessing I will need gain). Source is an old Rotel RCD-971.

The B1 immediately caught my eye (would have liked a B2 since I'm biamped), and am 150 pages through the thread. I was going to build with split rails to eliminate the in/out caps and add a second set of outputs w/gain (gain stage either discrete or OPA627/637). Hell, the CD player is probably loaded with opamps, so how bad could one more pair be?

Anyway, around page 150 the jfet BOZ is mentioned so now I'm starting to read through that thread.

Can anyone offer a suggested direction to save me a ton of more reading? modded B1, jfet BOZ, or is there something else I should be looking at?

Thanks for any help!

Oh, I'm a fairly experienced DIY'r.