I have had the Kenwood, Dyna and EV speakers. Your exact system. Your amp and preamp were just overhauled, so they should be good for another while. You might want to consider updating the crossovers ( more modern components ) of the EVs. If you are happy, I would stay with what you have, for now. If inclined to go more up to date with your amp / preamp, save up. It has been over a year that I eliminated my preamps, as I went passive ( both preamps were quite beyond the LO7C ), and my amp collection ( each and every one of them ) sound better than I can ever remember them sounding. I could not be happier. Granted, my passive is above your price range, but there are excellent units for much, much less. This is my own experience, but if you want to hear your source ( s ) like never before, I believe your ST70 and EVs would accommodate. Need more info, plenty of talk around here on the subject, and any questions, just shout them out. Enjoy ! MrD.