The Back Panel
1 AC POWER INPUT Plug the 7-pin DIN connector from the included power supply in here. Do NOT use a supply which is not expressly intended for the ATR-1a (even if you could find one with the that weird plug on it). Bad things could happen.
2 MIDI IN Connect the MIDI Out from a MIDI keyboard, sequencer, or other MIDI source in here.
3FOOT SWITCH Plug in a foot switch here. A 1/4-inch TS (tip-sleeve) plug is required. There are two varieties of foot switch: those that are shorted by default and those that are open by default. You should plug in your foot switch and then power on the ATR-1a. The ATR-1a will detect which kind of foot switch you have and behave accordingly.
4BALANCED LINE INPUTS Inputs can be 1/4-inch TRS (tip-ring-sleeve) Phone, 1/4-inch TS (tip-sleeve) Phone or female XLR.
Note: The XLR input is NOT a microphone input. A line level signal is required. Also Note: If you use a 1/4-inch TS plug, the input will of course not be balanced.
Yet Another Note: The two inputs will not mix two signals. Plugging in a phone plug will disconnect the XLR input.
5LINE OUTPUTs Outputs can be 1/4-inch TS (tip-sleeve) Phone Unbal- anced or male XLR Balanced.