Deriving the mono channel is accomplished by using the left channel posi- tive wire as the positive speaker wire and the right channel negative wire as the negative speaker wire. It is important that a minimum 4 Ohm imped- ance be observed.
INPUTS
M Series Amplifiers feature RCA inputs only. Run RCA cables from your sound source to the inputs of the amplifier. We suggest the use of high qual- ity shielded RCA patch cords to help reduce or eliminate unwanted noise in your installation. Be sure to run the RCA cables on the opposite side of the vehicle that you used to carry the power leads to the amplifier.
The input stage of the M Series amplifiers incorporates Xtant’s Balanced Line circuitry. This circuitry may be “enabled” or “disabled” via the Balanced Input Mode Jumper located above the RCA input jacks. With the Balanced Line circuitry “enabled”, the input sensitivity ranges from 100mV to 17 Volts. When in the “disabled” mode, input sensitivity ranges from 100mV to 8 Volts. Input sensitivity is adjustable in 10 dB steps via the Input Gain Select Jumper located above the Balanced Input Mode Jumper. Each of the five jumper positions correlate to a specific range of input signal levels. The chart below details the relationship between the jumper position and input signal level.
ADJUSTING INPUT SENSITIVITY
INPUT JUMPER |
| SIGNAL LEVEL |
= | 10 to 17 Volts | |
= | 3 to 8 Volts | |
0 dB | = | 1 to 3 Volts |
+10 dB | = | 300 mV to 1 Volt |
+20 dB | = | 100 to 300 mV |
The amplifier is shipped with the input gain set at the +10 dB position. If you do not know the output signal level of your head unit and you want to change the factory setting, simply move the jumper to the +20 dB position to increase the gain. Move the jumper to the 0,
The input circuitry operates similar to a line driver by increasing the signal level when placed in the +10 and +20 dB positions. The following chart illus- trates this function:
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