9
PRO MPA II OPERATING INSTRUCTIONS
Obtaining the best noise performance with the PRO MPA II
Start by turning down the Input Gain knob and centering the Analog Output knob. Use the analog
meter to view the operating level by depressing the switch under the center of the analog meter. The
meter will now indicate how much tube headroom there is. Set the +20dB switch to the out position.
Increase the Input Level knob until the meter reads above –10dB.
If you have turned the input knob fully clockwise and the indicated level is still below –10dB on the
meter, center the input knob and depress the Gain switch. Increase the Input Gain until there is
sufficient level.
This procedure optimizes the gain elements to provide the widest dynamic range possible.
Adjusting the Input Impedance
The same microphone can sound different on various pre-amps. One reason is that every pre-amp
presents a different load to on its’ input, some even change as gain is changed! Our third generation
discrete front end was designed to be absolutely transparent. Every nuance of the microphone is
maintained providing detail masked by inferior pre-amps. The Input Impedance control is one key
element in providing new versatility in voicing microphones.
NOTE: the Input impedance control only affects the cannon connector inputs. The ¼” instrument input
on the front panel is NOT affected by this control in any way. The instrument input impedance is
ALWAYS >
1M Ohm.
Dynamic microphones are affected as much as phantom powered units.
