When I got my 1st Spectral preamp (a DMC-10), I used it with a Levinson No. 23 and was very happy with that combination. My biggest complaints were with the Camac input jacks on the amps. Levinson claimed they were superior to RCA's. They might have been, but all the high-end interconnects I had access to at the time only came with RCA's, so I ended up using RCA-Camac adapters, which negated any theoretical benefit the Camacs might have offered. A year or two later, Spectral introduced the DMC-20. I was blown away and upgraded my preamp soon after. I knew that Spectral very strongly recommended the use of MIT cables, so I tried a pair briefly but didn't hear anything that compelled me to buy the MIT's (I was still using the Levinson 23). I did eventually upgrade to Transparent Audio interconnects (Karen Sumner had left MIT to start Transparent Audio; supposedly using similar technology to what MIT was using but different enough to avoid legal issues). I take all this marketing stuff with a large grain of salt, but to my ears, they sounded better than the MITs and were a little easier on my pocketbook. Anyway, I eventually decided to try tube amps and switched to a pair of Audio Research V-140s. The problem was: the V-140s use balanced inputs, and all my interconnects were terminated with RCA's. But, the DMC-20 has balanced AND RCA outputs. I ran down to a local music store and bought a pair of balanced interconnects, telling myself I just needed something temporarily until I could get some "real interconnects". My system sounded fantastic! My audio dealer loaned me several different high-end balanced interconnects, but honestly, I never heard much difference in balanced cables, at least not to the same degree that I had observed in un-balanced cables. The DMC-20 preserved the integrity of the full range of whatever signal source I fed it, and passed it along to the ARC monoblocks, where the 140 watt triodes worked their magic. I intentionally left out a lot of details about the rest of my system because the original post was inquiring about whether Spectral amps had to be matched with Spectral preamps OR VICE VERSA. I've never owned a Spectral amp, but I can say I never had a problem driving another brand amp from a Spectral preamp. Would an all-Spectral system sound better? Maybe.. I heard George Merril's system at Underground Sound (in Memphis) that really sounded great. Maybe not. There are too many variables to make a definitive statement. But, in my systems, which have continually evolved over the years, I've always been very satisfied with Spectral preamps. I've never heard a DMC-30, but I'll bet it sounds terrific. Even if they sounded exactly like my DMC-20, I'd love to get one just so I wouldn't have to jump up and run over to the system every time I wanted to change the volume. That sure would be an expensive remote!