Precision Power A100.2 owner manual System Tuning, Low Impedance Indicator

Low Impedance Indicator

AM II circuitry will lower output power to maintain uninterrupted operation whenever the amplifier senses an impedance load of less than 2 Ohms. The Low Impedance Indicator (left-side end panel) is provided to let you know when the amplifier is operating in this mode. It is important to note that there is no increase in output power below the 2 Ohm threshold. Maximum power is achieved at 2 Ohms.

In the case of a short circuit, AM II will engage to protect the shorted channel but will continue to play the unaffected channel. When this occurs, audible distortion will be heard. Turn-off the system and repair the short. Once the problem has been repaired, the amplifier will return to normal operation.

System Tuning

In order to achieve maximum signal-to-noise performance from a high quality mobile sound system, it is desirable to use high signal levels wherever possible in the interconnection cables. High signal levels will reduce the effect of induced noise. The peak level of an audio signal is usually determined by the clipping level of electronic components. The following procedure should be used as a guide when the system installation is complete.

Adjusting Equalizer Input Gains:

1.Turn the equalizer's volume control to minimum.

2.Turn the source unit volume 1/2 to 3/4 of maximum. If available on your unit, set the output level to maximum. Some units may have a switch.

3.If available, set selector switch to either input 1 or input 2.

4.Adjust all equalizer input gains to minimum.

5.For the chosen input play the respective music source. A loud music passage is desired.

6.For the chosen input, increase the left input gain control until the onset of audible distortion. Then decrease the gain prior to the immediate point of audible distortion. This setting will minimize system background noise and prevents overloading of the equalizer. Adjust, for the same input, the right input gain control for proper left / right balance.

7.Set selector switch to the alternative source unit, if used, and repeat steps 5 and 6.

8.Adjust crossover next.

Adjusting Crossover Input Gains:

1.Adjust all crossover gain controls to 0 dB, 1/2 of maximum sensitivity.

2.Adjust all amplifier gains to 1/2 of maximum sensitivity.

3.Turn the volume knob on the equalizer to a maximum of 3 o'clock.

4. Increase the gain of the crossover until the onset of audible distortion. Then decrease the gain prior to the immediate point of audible distortion. This setting will minimize system background noise and prevents overloading of the crossover.

5. Repeat step 4 for any remaining crossovers in the system.

6. Adjust the input gains next.

NOTE: In manu multi-crossover / accessory systems, the gain of some crossover and accessories may need to be further decreased to achieve proper balance.

Adjusting the Amplifier's input Gain:

1.Adjust the amplifier's input gain to 1/2 maximum sensitivity

2.Turn the volume knob on the equalizer to a maximum of 3 o'clock

3.Increase the gain (clockwise) until the onset of audible distortion. Then decrease the gain counterclockwise prior to the immediate point of audible distortion. This setting will minimize system background noise and prevents overloading of the amplifier.

4.Repeat step 3 for any remaining amplifiers in the system.

NOTE: Depending on the sensitivity of the system's preamp(s), the gain of the amplifier(s) may not need adjustments. Also, in many multi-amplifier systems, the gain of some amplifiers may need to be further decreased to achieve proper balance.