Thanks for the kind thoughts, whitestix. For those who are curious, this amplifier is a more advanced, second-generation Karna amplifier, first designed around 2005, and the result of a years-long collaboration with Don Sachs. More practical, two chassis instead of four, and benefitting from Don’s decades of experience in what works and what doesn’t, especially in a production environment.
My projects are usually proof-of-concept and kind of out there. Don’s experience makes all the difference for this collaboration, getting it off the ground and into the real world. He has a lot of great ideas, taking it even further, and these will be in the pre-production amplifiers at the Seattle show.
Whitestix, don’t feel left out. The amps you are listening to now are essentially identical to the show amps, just a little earlier in the production cycle.
It’s a fully balanced circuit, with 6SN7 input, 6V6 driver, and 300B output. It’s a high current, high speed design. I tested an early 2003 prototype at 500 kHz at full power, with clean-looking sine waves on the scope, with no visible flat-topping or triangle shapes. No, I won’t repeat that test again, and I don't encourage anyone else to do it, either.