Upgrade from Adcom GFP-750?


Having recently added a Bryston 9BSST, I'm thinking about upgrading from my Stan Warren modified Adcom GFP-750. I've been pleased with my Adcom's sound, flexibility and reliability, and I think I'll be even more pleased when the modified unit arrives. But I'm wondering if and how much better I could do within my budget (~$1500, used). I'd prefer to stay with SS. The main contenders are the BAT VK-20, Bryston BP25, and Conrad-Johnson PFR. Would any of these, or others not on my short list, represent a significant upgrade in sound quality? I appreciate your comments and suggestions.

System:
Adcom GFP-750
Bryston 9BSST
Linn Ikemi
Thiel CS2.3
Kimber KCAG ics
Acoustic Zen Satori cables
lmack
I moved from the Adcom GFP-750 to the Sim Audio Moon P-5. I've been delighted with the build quality and the sound. It offers all the transparency (and then some) of the Adcom in passive mode, yet has wonderful dynamics as well. It certainly is a remarkable unit.

Good Luck!
I agree with Marakanetz on the Pass Aleph P. Very nice pre with the same low gain as the gfp, but much nicer sounding.
yet you should stay away from bryston bp25. to my ears that's probably the worst gear they ever produced so far. it will certainly be a downgrade from adcom.
I used the Adcom both active and passive: active for rock, electronic, ambient; passive for jazz, classical, acoustic. I might be willing to increase my budget to retain the flexibility of both options.
You definitely like your Adcom. I think you'll like an Aleph P even more-the Adcom has a circuit design by Nelson Pass, the Aleph P is an all Pass Labs design.
I'm selling my GFP-750 & tomorrow I'll install my Pass Aleph P. It will stay in my system until I try a Pass X1 & come up with the money for one.....