User`s manual

Phase Switch

The Phase switch is provided to reverse the phase of a signal. This switch works on Pins 2 and 3 of the XLR Output jack

and also reverses the polarity of the 1/4” output jack. In the Normal (out) position, the signal is in-phase. In multiple

microphone applications, the placement of the microphones can affect the phase of a signal. If two microphones pick up the

same signal from different locations, the result can be a hollow or frequency “shifted” sound. In some cases it may sound as

if an instrument disappears if it happens to be 180 degrees out of phase. Depressing the Phase switch can remedy this

problem. Likewise, if a microphone cable is wired incorrectly, when used with a properly wired cable the signal will be out of

phase. Note: for single microphone applications, switching the phase switch in and out will produce little to no change in the

output signal.

Opto Comp Switch

An Opto Comp Bypass switch is included on the Tube MP/C to enable you to remove the compressor from your signal

chain. When set to its “out” (OFF) position, signal is allowed to pass from the preamp circuitry to the output level control

circuitry with no compression. The LED will glow green when the compressor is engaged. In its “out” position, the

compressor is bypassed. Use the Opto Comp switch when setting the Tube MP/C’s Output Level to achieve unity (no boost

or cut) gain. Unity gain is achieved when the "ON" level is the same as the "OFF" level.

Gain Reduction Display

The Gain Reduction display monitors the compressor gain. As an input signal exceeds the threshold level set by the user,

the compressor reduces its' gain. This Gain reduction is displayed by one of four LEDs.

For the most transparent results, adjust the threshold and slope to limit the average gain reduction to 9dB or less.

The Output Level Control

The Output Level control sets the output level of the Tube MP/C. When the control is fully counterclockwise, the output is

muted. Turning the control clockwise increases the level of the output to a maximum of +20dB of gain. If the Output Level

control is set very low (below the “-3” marking), you can set the Output switch to "Inst." level to better optimize the

TubeMP/C to your system's clip level. This is common when connecting to mic or guitar amp inputs.

Output Level Display

The Output Level LED display indicates the signal level present after the output control but before the Output switch. The

red CLIP LED lights a few dB before the internal circuitry actually clips. The yellow "0" LED lights when you have 12dB or

less of headroom before clipping. Note: The Level switch on the rear panel will shift the output level without changing the

level displayed on the Level display.