In Reply to: On the issue of balanced amplifiers... posted by RGA on May 7, 2012 at 05:16:40:
and there seems like a lot of confusion as the Audio Note article points out. But they did not cover all the scenarios.
We offered the first balanced line product to high end audio in 1987, the MA-1, which is a fully-differential OTL, balanced inside and out. We followed that in 1989 with the first fully-differential preamp, which also happened to be all-tube. The BAT founders were some of our first customers.
The scenario that the article omits is zero feedback differential tube circuits, fed by regulated supplies and highly effective 2-stage vacuum-tube constant current sources. The CMRR is greater than the noise floor of the circuitry, well above 110db. But that is what is at the inputs of all of our amps and preamps. It really is symmetrical.
That takes care of the even ordered harmonics (no classic tube sound) and the zero feedback and outright linearity takes care of the odd ordered harmonics (so its not harsh either). When you get rid of distortion, smoothness and detail are suddenly hand in hand; a lot like the sound of an SET at very low volume.
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Follow Ups
- We started this whole thing - Ralph 14:09:29 05/11/12 (6)
- RE: We started this whole thing - Tre' 15:17:05 05/16/12 (2)
- troll warning nt - Ralph 07:43:52 05/17/12 (1)
- What do you mean by "troll"? - Tre' 10:30:45 05/17/12 (0)
- RE: We started this whole thing - RGA 11:15:00 05/12/12 (1)
- looking to the same goal - Ralph 11:25:57 05/13/12 (0)
- RE: We started this whole thing - vince saunders 07:32:52 05/12/12 (0)