As Head of Design Engineering for Awesome Transistor Amplifier Company (AwTAC), Jens helped create the Panner/Mute/Summing module for AwTAC’s Table Top Mixing System. This product turns a Sweet Ten 500 Series enclosure into a stereo mixer, expandable up to 64 inputs.

As per AwTAC’s usual 1970 style manual, the circuitry employed had to be exclusively discrete transistor. Another requirement was 100% silent operation, to ensure that “on the fly” mixing would be free of clicks, pops, scratching, and any other audible noise. We satisfied both requirements in our opto-isolator mute block, coming up with a mosfet circuit that would convert the momentary switch pulses into a flip/flop ramping signal to drive the photo resistors, turning changeover between mute/unmute into a 10mS crossfade rather than an abrupt cut. A couple of timing capacitors enabled primitive logic, allowing end-users to “play the mutes” (quick touch on the beat) or “count out a bar” (hold and release). Meanwhile, thirteen varieties of high quality pan pot were evaluated so that we could use the one with least amount of track noise, and Jens’ cascoded JFET input buffer measures quieter than any IC op amp that we could’ve used instead.

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