I have a Jeff Rowland Model 10 amplifier and used a Synergy 11i for awhile but found it too analytical(read dry and not musical) in my system. I also had an older passive preamp from Placette Audio and while the sound was more transparent than the the Synergy I needed an active preamplifier with gain for my reel to reel recorder. I tried a number of tube preamps and ended with a Conrad Johnson 16LS 11 Linestage. It is a great match, the best of solid state amplification and a tube preamp.
