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