I have an older Rotel amp mixed with an old Adcom preamp for my office. They sound very sweet together. The Energy's suck though, I will be getting M22's to replace them. Mixing MFG's doesn't affect the sound or a least it shouldn't. The only reason I can think of to have the same MFG is for aesthetic reasons.

Tom



M80's VP150 QS8's Earthquake SuperNova MKV-15
Integra DTR-7.4 Outlaw 755 Outlaw M200's Outlaw ICBM