Four-channel matrix decoder that helped start the quadraphonic craze.
Solid-state American chassis from the 1960s-70s: the usual failures are dried electrolytics, dirty selector switches and, on receivers, the dial lamps and the tuner front end. Original wood cabinets and faceplates drive the price.
Marks that can be entered for this maker: Serial number, Model / catalogue number, British capacitor code (Hunts, Mullard), Japanese capacitor code (Nichicon, Chemi-Con, ELNA), EIA component code, Version & era marker.
Nothing predates 1969; components only push the date later.
Sold-price aggregates are not collected yet, so the archive gives no figure — condition, originality of the transformers and a documented recap move this model more than any list price.
Evidence: Wikipedia · Curcio Audio — Dynaco documentation · +1 more