My rodec sm300 converted to a rotary mixer. Did this conversion myself in summer 2015 after realizing that this would be the perfect mixer for something I had in mind for a few years, a rotary mixer project. Guess I was the first guy to come up with this idea on this specific mixer, never saw one before and neither did Rodec engineers that were awesome with me, flattering the job. A year or so later I decided to sell it to a buddy of mine when i was thinking about doing the isolator on it.
A one-off black prototype Allen & Heath Xone complete with valve stages on each of the 6 inputs (usually only available on the phono inputs, but was an available modification to both, the inputs & the external power supply)