Von Schweikert VR4/Amp combos that work?

I'm interested to hear from VR4 Gen III or VR4 SE owners who are satisfied with their present amplifiers and why. I am using a Bryston 14B SST with a First Sound Presence Deluxe II preamp, and EMC 1-UP CDP. While the system sounds very good, I feel the sweet spot is small. This small sweet spot is contary to what I have read regarding the VR4 SE's and I'd like to know if you other Von Schweikert speaker owners have amps in your systems that give you a larger sweet spot. I spent considerable time setting and positioning the speakers until I found the location that afforded the best soundstaging and sweet spot without definite "Left/Right" channel distinction and I'm wondering what might be done differently. Thanks in advance for your input.