The McGary Audio ‘Monoblock Amp One’ (MA1) uses an output pair of either KT88, KT90, or KT120 tubes, are rated 80WRMS into 8ohms (…with strong KT90s used at the show these measured 90WRMS), unbalanced (RCA) inputs only, Class AB push-pull ultra-linear output stage and something different-very large storage capacitance in power supply only using polypropylene capacitors (no electrolytic).
Of course low feedback design (less than 10dB) and point-to-point wiring with Cardas silver solder and Solen Teflon capacitors in the circuitry.
For the vacuum tube ‘Stereo Preamplifier One (SPA1)… a very simple purist design using only unbalanced (4) inputs/(2) outputs, a modified mu-follower tube stage, sensitivity control for sources that output either a hi or low voltage, and an ELMA precision (0.1%) resistor attenuator volume control (remotely controlled). The modified mu-follower design and placing the volume control after the tube stage (output side) rather than before (input side) allows for much more robust performance, precise balance with left and right centered exactly across all 47 positions of volume control, and reduced noise. The stepped attenuator is a precision ELMA-made device and the Source and Sensitivity switches are also manufactured by ELMA. These are very premium components. The front panel knobs are lit with LEDs so one can see their selection (sensitivity and source selection, and volume level). The tube cover panel on top of the preamp removes easily (4 screws) to access/change the 2 tubes.
The 6BQ7A (or 6N1P equivalent) tubes (one for each channel) are biased class A, low voltage, and coupled to the outputs with V-Cap ODAM capacitors. The power supply uses a capacitor multiplier circuit and single star grounding, accomplishing low noise, low distortion, and over 20dB gain (yes 20). The color of production units will be the same Midnight Blue Metallic and Satin Blacktop (powder coat).
The sound was very musical and precise. The midrange was warm and beautiful. Only sharp edges were on Jim’s fine cabinets not in the sound anywhere.