Front Panel Controls Overview
Input Control: The input control determines the amount of signal hitting the line
amp after the transformer stage and is very simple to use. The user simply needs to
rotate the control until the desired input level is reached.
Phase Switch: This switch, when engaged, flips the polarity of the input pre input
transformer and essentially switches pins 2 and 3 for 180 degrees of phase
correction. This is particularly nice on drums and other instrument where this type
of phase correction is necessary.
Pad Switch: This switch engages a 20db pad pre input transformer for those
instruments with a high dynamic range. Your converters and ears will thank you to
have the pad engaged when miking drums!
48V (Phantom switch): This switch simply engages the 48V on board phantom
for condenser microphones requiring a phantom power supply.
Output control: The output control is set up to control the amount of level sent to
the last stage of the amplifier and output transformer. This allows the user to
effectively drive the preamp harder without clipping the input of your converter,
Tape machine etc.
Impedance switch: This switch in its normal (low) position sets the input
impedance that the microphone sees at 300ohms. When engaged to the high
position, the impedance is switched to 1.2K, which also increases the amount of
gain capable of the preamp on higher impedance microphones.
Hi-Z input: HI-Z direct inputs on the M72 for instruments and line signal.
