Precision Power A100 manual System Tuning, Bridging, Inputs, Gain Control, Low Impedance Indicator

polarity before securing each wire. If inserting larger gauge wire presents a problem, tinning the wire with solder may help. Be sure the connection is tight. The connector may be plugged into the amplifier. (Refer to Figure C)

Bridging

All Art Series amplifiers are capable of being bridged into a mono output due to the internal design of the amplifier. This feature permits the creation of a mono channel for a subwoofer or center channel. Also, bridging adds flexibility of operation. Any of the Art Series two-channel amplifiers can be used in a one channel (mono), two channels stereo, or 3 channels - 2 channels stereo and one channel mono configuration.

Deriving the mono channel is accomplished by using the left channel positive 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 impedance is observed. If the impedance drops below 4 Ohms while the amplifier is wired in the mono configuration, the AM H protection circuit will engage.

Speaker Connector

Speaker Negative

Speaker Positive

Remote Turn-On

Speaker Positive

Speaker Negative

Figure C: Speaker / Remote Turn-On Connector

The ability to run stereo satellites while simultaneously running a mono output from the same output stage is accomplished simply by running the stereo speakers normally and tapping into the appropriate wires for the "Mixed Mono" channel (left channel positive wire as the positive speaker wire and the right channel negative wire as the negative speaker wire). Again, speaker impedance should be 2 Ohms on the stereo channels and 4 Ohms on the mono channel.

Inputs

On the left side panel of the two channel Art Series amplifiers are a set of RCA jacks. A DIN jack is paralleled to the RCA input and can be used to Phantom Power other PPI accessories, such as our crossovers and equalizers. The paralleling of these inputs allow the 'daisy-chaining' of input source to other amplifiers or accessories. Connect your source unit to these inputs.

Gain Control

On the left end panel, next to the inputs, is the gain control. This control adjusts the level of the input signal of your source unit. This control requires a small flat blade screwdriver for adjustment. Upon installation of the amplifier, the gain control must be adjusted. This can be done by first turning the gain all the way down (counter clockwise). Turn the volume on the source unit up two thirds. Then adjust the gain control until the desired volume is obtained without audible distortion.

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.

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