Mystere pa21 (open stock) – Everything we mention about the pa11 above applies here and more. This is a larger full-size amp, and is awesome. I can use most any tube including EL34, KT88, KT90, and even KT120’s. It’s 55 watts per channel from four KT88’s. When you look at this amp and hear it, you will fall apart. It has the same design as the ia21 integrated which was the best sounding integrated amp Stereophile’s Eric Lichte had ever heard during his review series in that magazine. Like the ia11 above, this is the perfect solution for the guy that wants single ended 300B sound but also wants the power you need for most normal speakers.
This amp sells for $2995. You lucky dude or dudes can have one with box, manual, warranty, and tubes that test new for $2099
Mystere pa21 Stereo Power Amplifier
The pa21 maximizes all our efforts with more power, more dynamics and greater flexibility. The full-sized chassis allows us to use larger transformers and bigger caps and resistors, delivering greater control and detail.
The result is 55 watts of pure pentode output per channel, and improved stability throughout the amplifier. We do implement a very modest amount of global negative feedback to make the amp rock solid.
With more room at their disposal, our engineers continued to search for improvements, such optimal efficiency, the lowest signal degradation and the greatest immunity from noise and hum. They accomplished just that, with carefully separated and laid-out signal ground, power supply ground and chassis ground schematics.
We’ve also advanced our proprietary Adaptive AutoBias board with a special circuit that re-calibrates it for EL34s or KT88s. One flick of a switch allows you to run either tube at its optimal level. And as always, the board continuously monitors each tube, tweaking it to its sweet spot. There’s no biasing, no need for matched tubes, no worries.
Power: 55Watts x 2 @ 8Ohm 1%thd
Freq. Response: 9hz-52khz +/- 1db @ 40w
Noise: < -90db A-weighted
Gain: 26dB (20x) at max volume
Distortion: 0.2% @ 1W, 1% @ full power
Inputs: 1 pair RCA
Outputs: 4 & 8 Ohm 5-way speaker terminals
Tube Compliment: 4 - 6SN7 & 4 - KT88
Power Consumption: 230w max
Weight: 60 lb (27 kg)
Dimensions: 16.9" x 7.9" x 16.4" (wxhxd)