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Has the Bottlehead team put any thought into an orthodynamic headphone amp, or perhaps a modification to an existing design (like the Smack) to better suit these headphones?
Looking over this thread, it strikes me that nobody has answered the original question directly yet. We are an excitable bunch!
To address that original question, I can say that we have indeed put a lot of thought into these (and other) lower-sensitivity headphones. Seems like every time I went over the Bottleheadquarters in the past year or two, the subject has come up; in fact it was one of the considerations that went into the Smack design, which could otherwise have gotten away with a much lower output capability, and possibly used the much smaller PT-1 power transformer at a lower price point. I don't know if there will be any LCD-2 or -3 'phones at the meet today, but I am very interested in what people hear. The higher-power option would be the SEX, but it is less refined, having two stages and no shunt regulator. Still, it was apparently well recieved with LCD-2s at RMAF. When the OT-2 output transformer kit is finished (it has a 32 ohm option) the OT-3 could be used instead giving 16-32-64-128 ohm choices.
The other headphone idea that keeps coming up is an OTL design for electrostatic phones. So far there do not seem to be enough of them on the market to make it worthwhile, and of course the design and safety challenges are substantial. But the subject never goes away completely.
As for amps and preamps, of course you all know we are working on a new DHT OTL preamp. We do keep butting our heads against the wall searching for a reasonable way to get 15 watts. No success yet.