I really cannot add much to the advantage/disadvantage of OTL amps, except to say that they certainly do possess a magic and realness that is hard to beat.
But, I would like to say something about the Zero autoformers. If they work for you, and you like them, then please just use them and be happy. However, I feel they are not a good solution whatsoever. They steal most of the OTL magic out of the sound, imparting a very white, bleached sound which makes me feel as if I am listening to solid state.
In my experience, the way to do it is to find speakers which present the amp an OTL friendly(that means high impedance) load.
Not to take anything away from Paul Speltz; the man is obviously a genius, when it comes to AtmaSphere amps, and his mods boggle the mind. Using the Zero autoformers will allow people with not the best matching speakers to be able to use OTL amplification. But again, it simply does not sound nearly as good as doing it the right way.
But, I would like to say something about the Zero autoformers. If they work for you, and you like them, then please just use them and be happy. However, I feel they are not a good solution whatsoever. They steal most of the OTL magic out of the sound, imparting a very white, bleached sound which makes me feel as if I am listening to solid state.
In my experience, the way to do it is to find speakers which present the amp an OTL friendly(that means high impedance) load.
Not to take anything away from Paul Speltz; the man is obviously a genius, when it comes to AtmaSphere amps, and his mods boggle the mind. Using the Zero autoformers will allow people with not the best matching speakers to be able to use OTL amplification. But again, it simply does not sound nearly as good as doing it the right way.