I have, in fact, done some listening. Eighteen of the boards are under construction; not pictured are the two boards that are completed and hooked up to temporary heatsinks, a σ22, and my source.
It is, to put it mildly, pretty damn good.
For the uninitiated: the above is a whole batch of DynaFET boards. These are a custom board layout that I'm in the process of building for a few people. Besides the actual amplifier, each has onboard monitoring of voltage, current, output transistor temperature, case temperature, and output offset servo position, and a relay for selecting between the two options for feedback point from the original design.
Each board has 24 BJTs, four input FETs, eight output FETs, seventeen caps (a few in the monitoring circuit and servo, one compensation, the rest power decoupling), about 60 surface mount resistors, fourteen through hole resistors, a pot, four LEDs, three ICs (microcontroller, sense opamp, servo opamp), four connectors, and... a partridge in a pear tree. The feedback loop resistors are 0.5% low-tempco thin film. The input JFETs are a matched quad, and the input stage BJTs are in matched pairs, thermally bonded into custom dual-TO-92 heatsinks.
Multiply all that by four boards per (balanced!) amp, and five amplifiers that I'm building.
And that's not even getting into the master control system...
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