Crown Audio MA-3600VZ operation manual Advanced Features and Options, Input Ground Lift Switch

Macro-Tech MA-3600VZ Power Amplifier

5 Advanced Features and Options

5.3 Options

5.3.1IQ-PIP-USP2 Adapter and PIP-Lite Module

Available in limited quantity through Crown’s Parts Department, the IQ-PIP-USP2 Adapter allows the ampli- fier to accept the Crown PIP-Lite module (but not the PIP-USP3 or PIP-USP3/CN.) Load monitoring and out- put voltage limiting are not available with the IQ-PIP- USP2 Adapter.

The PIP-Liteconnects the amplifier to a 100 Mb Ether- net network allowing it to be remotely controlled and monitored via IQwic or System Architect.

The PIP-Lite is a TCP/IQ series component. This means it connects to Harman Pro System Architect software or an IQ System® via 100 Mb Ethernet. This provides faster IQ communications than the previous current loop, IQ bus, connectivity method. With this control network option, a large (or small) system can be interconnected using standard off-the-shelf 100 Mb Ethernet compo- nents (Switches, NICs, and cables). The PIP-Lite can also be connected to the same network used to pass CobraNet™ audio1.

The audio path in the PIP-Lite is processed totally in the analog domain. While DSP-type functions cannot be supported with this type of architecture, the standard SmartAmp features are. These features include input compressors, multimode output limiters, and error reporting.

5.3.2 Input Sensitivity Switch

The Input Sensitivity Switch is located inside the back of the amplifier (Figure 5.1). It is set at the factory to 0.775 volt for rated output into 8 ohms. It can also be switched to a sensitivity of 1.4 volts, or a fixed voltage gain of 26 dB (4.8 volts for rated output).

How to change the input sensitivity:

1.Turn off the amplifier and disconnect its power cord from the AC mains power receptacle.

2.Remove the PIP module (two screws).

3.Locate the sensitivity switch access hole inside the chassis opening as shown in Figure 5.1. It is located just above the phone jack inputs.

4.Set the switch to the desired position noted on the access hole label. The position toward the front panel sets the sensitivity to 1.4 volts for rated output, the middle position provides a voltage gain of 26 dB, and the position toward the back panel sets the sensitivity to 0.775 volt for rated output.

5.Replace the PIP module and restore the power.

5.3.3 Input Ground Lift Switch

The Input Ground Lift switch is located on the rear panel (Figure 5.1) and can provide isolation between the input signal ground and the AC ground. It affects only the phone jack inputs and has no effect on the input connec- tors on the PIP module. Sliding the switch to the left iso- lates or “lifts” the grounds by placing an impedance between the sleeve of each phone jack and the circuit ground.

When a PIP module is plugged into the amplifier, only the noninverted and inverted signal lines are connected in parallel with the corresponding lines of the input phone jacks. The signal grounds are not paralleled. For exam- ple, XLR pins 2 and 3 are connected in parallel with the tip and ring of the corresponding phone jack. However pin 1 of the XLR is not connected in parallel with the sleeve of the phone jack.

Figure 5.1 Input Sensitivity and Ground Lift Switches

1Note that the IQ-PIP-Lite cannot receive or transmit CobraNet audio.

Operation Manual page 15