Available as an assembled Module and as a DIY project.
No info about availability.
Stereo Output Mixer
Synthrotek is pleased to offer a complete line of eurorack synthesizer modules, power, cases and accessories in both complete units and kits. We now offer a very complete analog modular monophonic voice with many accompanying utility modules. This new complete voice is the product of a collaboration with synth guru George Mattson, who now joins us in releasing our new MST (Mattson – Synthrotek) line of premium modules.
The MST Stereo Mixer is intended for pannable stereo output, but it is also suitable for both AC & DC voltage signals (Gates, Triggers and Control Voltage).
Features:
2 channels, 2 inputs per channel
Jumper select ~unity gain or gain ~x2 (6db boost) amplification
Mixes both AC signals (audio) and DC signals (gates, triggers, CV)
Stereo output with panning per channel
Attenuator and amplifier per channel
1/4” and 3.5mm (1/8”) matching stereo output jacks
Black & White Panel Option!
http://www.synthrotek.com/products/mst-eurorack-modules/mst-stereo-output-mixer/
These merchants probably sell this module. Huh?