How is the OTL sound like?

I use Atma-Sphere, the M-60 Mk II.2. These are a revelation. Their reproduction of dynamics, high frequencies, timbre, timing, bass, control is amazing. These are easily the most fluid, grain-free tube amps I ever heard. Super fast, clean and clear, natural and balanced for the whole spectrum, they are superb. I believe, I had a mesmerized look in my face, when I first listened to them. There is everything I hear from my Pass amps AND MORE. They give me every detail with lots of air, combined with brutal power in the bottom without being euphonic linked with stunning speed and transparency. In any case, the sound these amps produce is almost frighteningly real - clean, open, "air", wide soundstage, unbelievable detail - it's all there and then some. And : there is NO "warmth" or other tube-related anomalies - just clean, accurate musical amplification.

Thomasheisig is spot on. OTL's are simply more pure and natural but need to be matched with the right speakers to get the best out of them, and extend their tube life. Sensitivity is less critical than the ohm load they produce over the frequency spectrum. Look for speakers of at least 6-8 ohms with minimal phase angles. The higher the Ohms, the more dynamic and powerful will your amps sound.

Ditto to what's been posted above. When I first heard my Atma-Sphere M-60's (I bought them used, without an audition) I literally had that same warm/fuzzy feeling I had when I was courting my wife.

Thomas, did you first hear the M-60's paired with the Köchel's? If so, I can imagine how intensely profound your experience was. It is profound even when listening to this combination on a daily basis.

I have owned the Atma-Sphere MA1 and M60. I have also had the MA2 in my system and OTL is the way to go IMHO. Now I haven't heard other OTL designs so this might just be an Atma-Sphere thing but these are the best amps I have heard or had in my system. The only drawback is they run hot. Now I don't know too many Class A amps that don't run hot. You do need to listen to OTL designs.

I've owned 2 OTL amps and I liked the sound of both of them very much. I still have one of them, and expect to keep it for a long time. It is very hard to go back to traditional output transformer amps after hearing a good OTL amp.

I agree with most of the above comments, especially the one about using speakers that have 8 ohm loads or more. The output impedance of OTL amps is usually higher than transformer coupled amps, and the higher speaker load gives them a better match.

Thanks everyone to educate me. I am thinking about one to match with my Merlin vsm-se.

Thanks again

Vxphan for the Merlins I recommend you listen to, if you can, both the Berning zh270 and the Joule. You can't go wrong with either although each give a different presentation. but offer that speed, clarity and presence that is the hallmark of this design. The Transcendent is also very good, less expensive but also less power. It may not be enough but for a small space. The Atma-spheres I haven't heard with the VSM.

dear folks,

what are these speakers have more than 8 ohm? i have Virgo II, can these match with atma sphere??
thanks

Tim

Hey Tim

I believe the Virgo's go down to 4 ohms? This would be marginal with the Atma-sphere but this is where the zero autoformer comes into play with such a load. Your other options are the Berning which by ears I trust work quite well with the Virgos.

Dynamic Speakers with greater than 8 ohms are few. Coincident is probably the best example. 8 ohms will work quite well with most OTL amps. The big Atma-sphere's and Joules supposedly work into 4 ohm loads but not anything less.

Hi, Tubegroover,

OTL is the amp i have been thinking for awhile, but always worries about the matching problem. you are right that virgos are 4 ohm, it concerns me a bit.
thanks

Tim