The Facts about Personal Mic Mixer

Problem: You need to add 3 mics to a mixer, which only has one available channel.

Solution: Insert a ProMIX between the mics and the mixer. Each mic channel on the ProMIX has both phantom power and low-frequency cut selectable via DIP switches plus a level control. The balanced XLR line output can be connected to a mic input on the mixer and headphones or a powered monitor can be connected to the Phone/Aux output. If AC power is not available, the ProMIX runs on batteries as well.

Specifications:

• 3 low-impedance XLR mic channels
• 3 level controls
• 3 phantom power on/off DIP switches
• 3 low-frequency cut on/off DIP switches
• A low-impedance balanced XLR line output
• Mono 1/4" Phones/Aux. output
• Clip LED (indicates signal at 3dB below clipping)
• On/off Power switch, with LED
• Power: 12V DC (Adapter included)
• Output Phantom Power: 12V (Using the 12V DC supply)
• Optional 2 x 9V Battery Power (Yields 18V Phantom Power)
• Low Cut Filter: -3dB @ 100Hz
• Input and Output Impedance: 600 ohms
• Total Harmonic Distortion (THD): 0.02%
• Maximum Output Level: +14dB
• Maximum Input Level: -14dB
• Clip Headroom: 3dB
• Maximum Gain: +60dB
• Dimensions (HWD): 1.75 x 5.75 x 4.5 inches (44mm x 146mm x 114mm)
• Weight: 2lb (0.9kg)

Usage:

1. If you are using the 12V AC adapter, connect the cable end to the ProMIX's 12V DC input and plug the other end into a 120V AC outlet. Otherwise, make sure there are two 9V batteries connected inside the battery compartment.
2. Connect low-impedance mics to the 3 XLR inputs with mic cables.
3. If any mics require phantom power, set the appropriate PHNT PWR DIP switches to the on position (down).
4. To avoid picking up unwanted low-frequency noise (rumble, thumps, etc.), it is advisable to roll off the low frequency response of mics other than those specifically for bass drum, bass guitar amp, upright bass or keyboard amp. For all other mics, set the Low Cut switches to the on position (up).
5. Connect the balanced XLR (male) Output to the mic input on the mixer with a low-impedance mic cable.
6. Connect headphones to the Phone/Aux jack. Alternatively, this jack can be connected to the unbalanced input of an amplifier, another mixer, etc.
7. Flip the Power switch to the on position. The PWR (power) LED will illuminate.
8. Adjust the Level controls for the desired mix and check the Clip LED to make sure one or more of them are not turned up too far. A small amount of Clip LED activity on occasional peaks is acceptable as it fires 3dB below the onset of actual clipping distortion.
9. Adjust the input gain of the other mixer for best signal strength without distortion.

Diagram Description:

The ProMIX features three input channels, each equipped with selectable phantom power and low-frequency cut (Low Cut) via DIP switches, followed by a level control. These three channels converge into a summing stage, which then outputs to a balanced XLR line output. The diagram also indicates a separate 1/4" Phones/Aux output. Front panel indicators like the Power LED and Clip LED are also implied.