Your system is just like mine, 3 years ago I started with Sonatina II and SLI 80 then a year later I added 1 Rel sub (I believed it is series 1) then last year I switched from SLI 80 to 300 SEI LX20, using KR 300 bxls tube, 20 watt/channel, it sounded really great, quiet, powerful and has many details of sound coming out from the speakers, I strongly recommend this changes. Now, I am in the process of adding a tube pre-amp and use my integ. amp as an amplifier and hopefully later on moving to monoblocks and also I've heard adding a s.s. amp to drive the lower freq. will be a big plus, what do you think?
Ron.
Ron.