What? Martin effect pedals? Yes, that's right. In 1989, Martin (as in C.F. Martin & Co. from Nazareth, PA) offered a line of effect pedals under the name "Stinger"—each with the Martin name proudly stamped on the underside.
These Martin-branded pedals were made in Japan by Aria, and although they actually sound pretty good, they were a tremendous flop. Martin's dealers were acoustic-oriented shops, and they simply didn't know how to sell them. After about 6 months, the project folded, and very few Martin Stingers actually made it out into the public.
The CH-70 covers the Chorus side of the Stinger line, and its sound is very similar to other 1980s MIJ two-knob chorus pedals. The chorus effect uses a small time delay that is varied to produce a slight pitch bend. When the delay signal is mixed with the dry input signal, the resulting sound moves with a rich, thick undulation as if multiple voices are played in unison. The CH-70 has two controls: "Speed" which sets the rate of the modulation, and "Depth" which essentially controls the intensity of the effect. Like other '80s chorus pedals, the CH-70 also has a stereo output, so you can isolate the dry signal from the wet, effected signal.
This 1989 Martin Stinger CH-70 shows some paint chips around the edges as well as general wear and tear (it gets stepped on, after all), but it functions 100% as it should. There is some adhesive residue on the bottom from velcro in the past, so it's obvious someone got some mileage out of this one. It is a cool piece of a Martin history, but it's also an authentic '80s chorus pedal that sounds fantastic!