OTL Asylum

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RE: From what I understand the Zero's...

Posted by Lew on May 15, 2017 at 13:05:16:
(1) The impedance conversion afforded by the Zero autoformer is much lower than that of any conventional tube output coupling transformer, because the impedance matching can be as low as 2:1 and almost never more than 4:1. (The output Z of the OTL is nearly the same as that of the speaker, usually at least a bit less.) Whereas in a conventional transformer coupled (OTC) tube amplifier, you are facilitating an interaction with power tubes that have output Z in the thousands of ohms to a typical speaker with a Z of 4-16 ohms. This makes for wider bandwidth and lower distortion for the Zero vs the conventional output transformer. The job of the output transformer is much harder.
(2) Because it's an auto former and because of the reduced workload, you would not have hysteresis distortion, or at least much less of it.
I don't say the Zero is perfect, but I do say that to my ears the combo of the Zero with an Atma OTL is still superior to every OTC tube amp I have tried on the same set of speakers. Audio is full of trade-offs. If you want to stamp your feet and walk away in protest, that is your privilege. Or find a pair of speakers that don't need the Zeros.