QUICK TIPS TO REMEMBER:

1. Please read this owners manual before operating.

2. Always make sure your cables, batteries and connections are in good condition and properly installed.

3. Turn the MDB-1 on first to avoid turn-on transients, and turn off last to avoid turn-off transients.

4. Failing to turn off the unit after use will result in greatly reduced battery life. Store in a place where it won't get accidentally turned on.

5. When installing or changing your batteries, be sure to observe correct polarity. If, after installation, your product does not turn on, immediately turn off and check your batterys.

6. Before each use, check for any damage to the MDB-1. Make sure all screws and connections are tight.

Front Panel Features

INPUT JACKS
Inputs 1, 2, and 3 will accept any standard mono source. Connection should be made using shielded cable terminated with a 1/4" phone plug. All inputs can be used simultaneously or one at a time. The in/out switches and volumes correspond to the numbered inputs (i.e. volume 1 and the in/out switch above it control input #1, etc.).

STEREO INPUT JACK
The Stereo input can be used with a stereo instrument or source such as an CD Walkman, Alembic bass, or an acoustic instrument using a pickup and soundhole microphone.

When a stereo 1/4" plug is inserted into this input, the Tip is fed to channel 1, and the Ring is fed to channel 2. Therefore, the mono 1&2 inputs become inactive and cannot be used simultaneoulsy. However, #3 input is still active.

NOTE: Maximum input level is 2 volts RMS with fresh batteries. Input impedance is 10 Meg ohms.

VOLUME CONTROLS AND IN/OUT SWITCHES
To activate an individual input, push the appropriate in/out switch to the in position. To mute an input, click the in/out switch to the out position. The volume control (vol 1, etc.) directly below the in/out switch adjusts the level of that channel at the output jacks.

If you are using several instruments with different output levels, you can "equalize" each instruments level by adjusting its volume on the MDB-1 before a live performance. This will eliminate the need to adjust levels during the show as you change instruments.

In the studio, or other venues, a sound engineer may need to know what unity gain, or the x1 position is on the volume control (this means when the input and output levels are equal). Unity gain equals the 12 o'clock (pointer straight up) position on the volume
control. Maximum gain is 3X or 9.5 dB with the volume full.

AUXILIARY BLEND
This feature is activated when a plug is inserted into the Auxiliary In jack. The control will "blend" in the signal at the Aux In jack with the signal at one or all of the activated inputs. It can also be thought of as an "effects return" level. Turning the control clockwise mixes in more of the Auxiliary In (wet) signal with the inputs (dry).

MUTE SWITCH
Pushing the Mute button to the in position activates this feature. This is indicated by the red LED lighting and the green Power LED going off. This silences or "mutes" the signal at the Line Out and XLR Balanced out. It does NOT affect the Auxiliary Send. This is especially useful if you have a tuner hooked to the Aux Send jack as it allows you to "tune up" without sending a signal to the audience or sound engineer.

Pushing the Mute to the out position re-activates the Line and XLR outs, and the LED's will reverse. Since battery drain is the same in the Mute position, do not leave it in for extended periods.

POWER SWITCH
Pushing the Power Switch to the "in" position turns on your MDB-1 as indicated by the green LED lighting. Turn the MDB-1 on first, just prior to connecting it to your other equipment. This will avoid a turn on "thump" from being heard. Always turn off the unit when not in use to conserve battery life.

Rear Panel Features

BATTERY HOLDER
A battery holder is provided for easy installation of 2 nine volt batteries. Be SURE and install them correctly. The + side (smaller of the two terminals) goes to the left. Once the battery has been inserted, push the box in the holder until it clicks in place.

XLR BALANCED OUT and GROUND LIFT
A true balanced output you can use for recording direct to tape, or sending a signal to a mixing console, etc. The XLR out is extremely accurate and quiet and is a perfect match for DAT recording and DI applications. The Ground Lift switch, when moved to the "up" position, removes the ground at Pin 1 on the XLR jack. Pin 2 is +, and Pin 3 is -. Always start with the ground switch in the "GND" position.

AUXILIARY SEND
Present at this output is the signal from any or all of the activated inputs. It can also be thought of as an "effects send" jack. Via a "Y" cord, more than one piece of gear may be connected at a time, such as a Tuner and an Effects device. The Aux Send is not affected by the Mute feature. Always use shielded cables. Output impedance is 100 ohms.

AUXILIARY IN
Inserting a plug into this jack activates the Auxiliary Blend control on the front panel. Use only a mono 1/4" phone plug. Input impedance is >27K ohms. This feature may also be thought of as an "effects receive" jack. Together, the Aux Send and In make for a side chain effects loop, similar to that found on a mixing console.

Use the Aux In to mix (with the input signal) a mono tape source, another MDB-1, an effects device or any mono source. If you don't hear a signal from the Aux In present in the Line or XLR out, check the position of the Auxiliary Blend control on the front panel.

LINE OUT
Present at this jack is the mixed signal from the inputs and the Aux In, if in use. This output can be used to send your signal to an amplifier or any mono input desired. Output impedance is 100 ohms. Always use a shielded cable for connections.