The vintage Ross Compressor is an iconic, highly sought-after effects pedal from the 1970s. It is an OTA (Operational Transconductance Amplifier)-based compressor known for its smooth, musical squash and long, singing sustain. The pedal features a simple two-knob control layout for Level and Sustain and is a foundational circuit that has been imitated by many other boutique builders. Its solid metal enclosure and distinct gray color have made it a "holy grail" pedal for collectors and players seeking its classic tone.