I'm not too far off of this so I will respond. I had an LFD Zero III with Harbeth speakers. When I made a speaker change and switched over to Totem Mani's, I needed a lot more power. I went to Belles 350A Reference. I have used a Herron VTSP-1A preamp, and a Belles 21A preamp. For me, it was a step up, but keep in mind that my speakers are particularly power hungry. As you know the LFD is excellent. I prefer the detail AND the musicality combo of what I have, which is in the neighborhood of your combo. But with Harbeths, the LFD was just absolutely dialed in. When I went to another speaker, excellent, but not quite the perfect match. With the Belles and tube amp combo, I got improved soundstage and the things that tube does in the midrange. I'd be really suprised if you improved on things with making a change to LFD. I had an AI M 3A once, but didn't try it with the Belles. Nice preamp.