$4500 amp beat out the Tenor OTL in the latest TAS

Are the Atma-Spheres powerful enough to drive the 4 ohm Infinity RS 1B's? I was always under the impression that they needed the 100-200-300 wpc to really sing. I will have to check out the Atma's!!

I think that the big Atma-Sphere could drive them fine, but you'd have to have the impedance matching transformer in line with them. Once you do that, then it is no longer an OTL, because you had to put the transformer back into the line to handle the 4 ohm load. Then you have the complexity disadvantages of the OTL and the disadvantages of the output transformer too. Much of the OTL benefits are lost in this transition. I'd use a straight high power push-pull amp for this application.

......Like the Hurricane??? or ARC 200 or VTL 450???? Right?

Yes, those are all high-powered push-pull transformer-coupled amps. After I bought the VTLs in the story I related above, I believe the previous owner was ordering the outboard transformers for his Atma-Spheres (MA-1's, if I recall correctly, but I can't remember what his speakers were). I kind of wonder what his results were, and if the Atma-Sphere circuit retains any of its possible superiority even when used with an output transformer. Of course, being that he was still awaiting the trannys at the time the VTLs went to me, he wouldn't have been able to do any direct comparisions of his results with the old amps he said he missed somewhat. Even so, the amps I got cost about half what his new ones did (in retail terms), so I wouldn't be surprised if there was utlimately some improvement. Maybe I'll email him and ask him how everything came out in the end.

Zaikesman, the output transformer for the Atmas-pheres you are referring to in your last post is maybe the zeroformer(?) which acts as a passive transformer and increases the turns ratio of the amp so the load from the speaker to the amp is optimally realized at 16 ohms.

The zeroformer, designed by Paul Speltz (Atmas-phere also markets or did market one) has several wires connecting to the autoformer that act as a multiplier. The multipliers are 1.37X, 2X, 4X, and 8X. As an example, an 4 ohm speaker would be set at the 4X setting to realize an ideal 16 ohm load. The downside is that the sound does tend to get a bit drier and more solid stateish. It works but does tend to affect the sound of the amp especially at the higher multipliers.