Turn back! That way lies madness! A move to tubes may result in a wholesale rebalancing of your system. By the time you finish you may not have much of the original system left...
OK, now I've got that off my chest, the problem with making a "small change" like a preamp is that the most crucial pairing in a tube system is the amp and the speakers. To my ears, that's where the real mojo lives. That being said, the easiest way to get a taste of tubes in your system is to bring in a tube pre. I've owned two - the Audion Premier and the Canary Audio 801 line stages. Both are excellent, but with different strengths. I really like what Canary does, and it may be possible to pick up one of their products used. Definitely buy used, because you may decide to move past whatever you get at this point.
If you decide that low-powered tubes are for you, allow me to recommend a line of speakers many haven't heard of - Fab Audio out of Toronto. Their Stonehenge is a remarkable buy for the money, and the big Model 1 (which I've been using for the last week and a half) is just plain remarkable. Feed either of them half a dozen good watts and you'll wonder where the music has been all your life :-)
OK, now I've got that off my chest, the problem with making a "small change" like a preamp is that the most crucial pairing in a tube system is the amp and the speakers. To my ears, that's where the real mojo lives. That being said, the easiest way to get a taste of tubes in your system is to bring in a tube pre. I've owned two - the Audion Premier and the Canary Audio 801 line stages. Both are excellent, but with different strengths. I really like what Canary does, and it may be possible to pick up one of their products used. Definitely buy used, because you may decide to move past whatever you get at this point.
If you decide that low-powered tubes are for you, allow me to recommend a line of speakers many haven't heard of - Fab Audio out of Toronto. Their Stonehenge is a remarkable buy for the money, and the big Model 1 (which I've been using for the last week and a half) is just plain remarkable. Feed either of them half a dozen good watts and you'll wonder where the music has been all your life :-)