Milkman Sound F-Stop Reverb and TremoloThe F Stop brings two effects found in vintage American tube amplifiers into one pedal. The combination of a tube driven spring reverb with pulsating "bias" tremolo was first introduced in the early 1960s and has become a standard sound for guitar players and other instrumentalists ever since. The F Stop has been designed to bring classic tube amplifier effects into a small package that runs off of a 9VDC pedal power supply. Internally, the F Stop has