Alesis 12R manual Phantom Power will not be Used

Connections

Balanced +4 dBu line level sources: Professional recording and processing equipment typically provides a balanced, 3-conductor signal output that is a higher voltage (1.24 volts nominal level) than most synthesizers and stereo equipment. The Multimix 12R’s [LINE IN] jacks are designed to handle these balanced inputs.

Balanced sources often feature XLR outputs. However, they should NOT be connected to the XLR [MIC] inputs of the Multimix 12R unless absolutely necessary, because the higher gain of the MIC jacks gives you less headroom than the LINE IN jacks do (also, the source could be damaged by phantom power if it's turned on). Connect them to the [LINE IN] jacks using an XLR-to-1/4 inch phone TRS (tip-ring- sleeve) cable, as shown below:

If the proper connector cable or adapter is not available, +4 dBu line level sources may be connected to the [MIC] jacks ONLY IF

PHANTOM POWER WILL NOT BE USED!!

Connecting a line-level output to a phantom-powered XLR input on the Alesis Multimix 12R may cause damage to the external unit. Alesis cannot be responsible for any damages caused by this kind of misuse.

The nominal trim setting for a +4 dBu signal plugged into a line input is approximately 11 o'clock (12 o'clock on the stereo channels). This will give you plenty of headroom to start with.

Maximum levels: The maximum level the [MIC] jack can receive with the [TRIM] control full counter-clockwise is +12 dBu before clipping, so there’s only 8 dB of headroom if you plug a +4 dBu line source into the mic jack. The [LINE IN] jack on channels 1-8 may receive levels up to +32 dBu without clipping, a headroom advantage of 20 dB. The stereo channels may receive a +22 dBu (balanced or unbalanced) maximum input.

Multimix 12R Reference Manual 11