Yes, I recently added the REL sub, and it's a jaw dropping combination : - ) I thought the 300 SEI LX20 was an amp, not an integrated, no? Anyway, great to hear that this change was worthwhile.
As to maximizing sound of SLI-80, I have been playing around with SED KT-88's vs Svetlana EL-34s (love both, actually). I experimented quite a bit with triode vs ultralinear - now I use exclusively triode - and also tried both Ohm setting on the back. I also experimented with various settings on the bias. I now keep it between 75 and 79 ususually. It's amazing how even a small bias drift can affect the sound. I thought sounded soft last week, turned out the bias had drifted to 71. Fixing it tightened up everything. Then there are cables.... I ended up with a mix of Quattrofil and Audience AU24. My old Cardas Golden Ref, which were fantastic with everything I threw at it, seemed a bit too laid back for this already laid back gear.
Art
As to maximizing sound of SLI-80, I have been playing around with SED KT-88's vs Svetlana EL-34s (love both, actually). I experimented quite a bit with triode vs ultralinear - now I use exclusively triode - and also tried both Ohm setting on the back. I also experimented with various settings on the bias. I now keep it between 75 and 79 ususually. It's amazing how even a small bias drift can affect the sound. I thought sounded soft last week, turned out the bias had drifted to 71. Fixing it tightened up everything. Then there are cables.... I ended up with a mix of Quattrofil and Audience AU24. My old Cardas Golden Ref, which were fantastic with everything I threw at it, seemed a bit too laid back for this already laid back gear.
Art