Atma-Sphere MA-1 amps

Biased as an owner could be, I'm very happy with these amps, and have lived with many others(check my system page: "Crisis Narrowly Averted". The Atmas have a clarity and ease of presentation that few amps do. The midrange purity is remarkable, highs are crystal clear w/o being bright. Complex orchestral and other pieces are easily untangled allowing 3D images surrounded by air if the rest of your rig is capable.

All this is IF & ONLY IF matched with an appropriate choice of speaker. OTLs and MA1s in particular need to be paired with speakers with an impedance of 8ohms or higher. If you have 4 ohm speakers, you'll need an autoformer such as Paul Speltz Zeros, which might be good, or might affect the sound(I haven't heard them myself).

From a reliability standpoint, they're built like tanks, mostly only ever needing tubes to be replaced. Ralph and his team are superior at support to make sure you get the most out of your gear. That point alone is worth focusing on. Ralph is a rare treasure, and worth reading about.

One caution, they run warm, and although not a problem for me, some worry about that. Cheers,
Spencer

Spencer has said it all. I wholeheartedly agree.

The most truthful-sounding amps I've heard, but not everyone prefers such a presentation. The better the recording, the more you will hear the amps' virtues - if you listen mainly to compressed pop/rock you can do as well for much less cache. A fully balanced (input through output with no ground reference to earth) is a must to get the best from Ralph's OTLs. That said, I'm a very satisfied MA-1 owner with a lifetime supply of tubes and will delight in great sound for many years to come.

Correction: "A fully balanced...PREAMP..." is what I meant to write.