MDP-1 Condensed Operating Instructions

    
(Click on front panel for larger photo)

   
DI INPUT: The DI input selects between Instrument (with 10 M input impedance at the front 1/4" jack, or 1M at the rear jack) and Line (100K input impedance, with a -20dB pad at both inputs). The 1/4" front and rear panel jacks are wired so that the rear jack is disabled when the front jack is used.

MIC/DI: Selects between the MIC input (via the XLR input connectors on the rear panel) or DI input signals (via the front or rear 1/4" input jacks).

+48V: Supplies 48 volts to the XLR inputs for condenser microphones requiring phantom power. Do not use with dynamic, ribbon or tube mics.

0/-20: The -20 position inserts a 20 dB pad in front of the mic input transformer.

+/-: Mic phase reverse switch, where '+' is normal phase (input pin 2 hot), and '-' is inverted phase (input pin 3 hot).

MIC LO CUT: An 11 position rotary switch that provides a gentle (6dB/octave) low frequency rolloff with 10 user-selectable turnover frequencies (20 to 180Hz). The low cut filter does not affect the DI input signal.

GAIN: An 11 position rotary switch that controls the gain of the tube stage in 3dB steps. The range is: +33 to +63dB for the mic input, +20dB to + 50dB for the DI instrument input, and 0 to + 30dB for the DI line input.

OUTPUT: A passive attenuator that controls the output level to the XLR and 1/4" (parallel) output connectors. By increasing the Gain (driving the tubes harder) and lowering the Output level, subtle variations in the character of sound are possible. For the 'cleanest' sound, set the OUTPUT control to 10, and adjust the GAIN setting for the proper signal level.

METER

OUTPUT: In the Output position, the VU meter indicates the signal level at the XLR and 1/4" output connectors (post-Output control). The meter is electronically isolated from the signal path, and is calibrated to 0VU = +4dBu (1.23Vrms).

GAIN: In the Gain position, the VU meter indicates the signal level of the tube gain stage (pre-Output control). The meter is electronically isolated from the signal path, and is calibrated to 0VU = +20dBu (7.75 Vrms).