Whirlwind PA-1 Personal Headphone Monitor

The PA-1 is a portable headphone monitor with high output and low distortion. It gets used to add monitoring to a piece of equipment that has none, to boost a weak headphone output in a loud room, as a position in a headphone distribution system, and for sign language or translation work where somebody is listening for hours and the sound quality decides how tired they get.

It accepts balanced or unbalanced stereo line level through parallel XLR and 1/4 inch TRS inputs. A switch changes the input configuration from separate balanced inputs to a combination unbalanced mode, with tip and pin 2 as left and ring and pin 3 as right, for taking a signal from a headphone output. Power is two 9 V batteries in easy access drawers or the included external PS24 supply.