Tireguy - Very interesting. I do not own the Berning. What I gathered from the user and the website is that the Berning was an OTL.
Closer reading of the Berning website shows me this:
The ZH270 takes advantage of new technology in order to eliminate the audio-output transformer. The application of this technology is the subject of a pending patent. The ZH270 uses radio-frequency to change the voltage-current transfer characteristics of the output tubes from their normal impedance-plane to one suitable for driving a speaker. The radio frequency impedance conversion is implemented using special high-frequency power-conversion techniques. The high-voltage, low-current tube impedance-plane is changed to the high-current, low-voltage speaker impedance-plane through special transformers at a constant carrier frequency. Because the audio signal is riding on a carrier, it is not subject to the parasitic elements of the transformer that would otherwise distort the audio signal. There is no low-frequency limit for this impedance conversion, and the ZH270 is dc-coupled, with the exception of a small, high-quality, dc-blocking capacitor at the input of the amplifier.
So you may be right. Maybe there are transformers but certainly not used in the way most non-otl amps use output transformers.
Nothing can beat the magic of an OTL in the right system huh? I cannot comment - maybe Kondo would have something to say about that? :)
Hey.. if the Tenor is OTL (and I know it is) then what are those boxes on the back of the amps? Help me here, are those input transformers?
