Electro-Voice Q44, Q66 Groundlift, LPN-Filter, Professional Power Amplifier, Owner‘s Manual, Dual

PROFESSIONAL POWER AMPLIFIER

2.6 Groundlift

The ground lift switch allows for eliminating noise loops. When operating the power amplifier together with other equipment in a rack case, setting the switch to the GROUNDED position is recommended. Set the switch to UNGROUNDED, when the power amplifier is operated together with appliances with differing ground potentials.

2.7 LPN-Filter

The patented LPN (Low-pass notch) filter corrects the frequency and phase response of the connected loudspeakers. This effect can not be reached using equalizers or „Bass-Boosters”, because the LPN filter mainly optimizes the rise time of the audio signal. Switch the filter ON or OFF for evaluation of the actual effect that the filter has on the sound. The sound is getting more powerful, especially when using fullrange speakers (e.g. 12/2, 15/2) or subwoofers. For large systems (e.g. controlled via EV‘s DC-One) using the LPN filter is not recommended.

2.8 Selecting the Mode Of Operation and Audio Output Cabeling

The MODE switch on the power amp‘s rear panel defines how the audio inputs handle the input signals. Possible settings are DUAL, PARALLEL or BRIDGED.

DUAL

In DUAL mode, the two channels of the power amplifier work independent from each other. This mode of operation is being used for all 2-channel applications, like stereo operation. Using the input level controls on the power amp’s front panel allows independently adjusting the channels’ amplification.

PARALLEL

In PARALLEL mode, the inputs of channel A and channel B are directly electrically linked. The audio signal has to be applied to the input connectors of channel A. Using the input level controls to independently control the amplification of the two channels is still possible because only the channels’ inputs are linked. PARALLEL operation is the mode of choice, whenever the same input signal drives multiple power amp channels of a large system installation.

CAUTION:

In PARALLEL mode, the input signal has to be fed to input channel A only.

Typical Speaker System Cabling

The first possibility in DUAL or PARALLEL mode is to use the two Speakon-type connectors, whereas speakers have to be connected to pins 1+ and 1– of the sockets. The correct connection is also indicated at the amplifiers rear panel.

Bi-Amp Cabling

The second possibility for connecting the speakers when the power amplifier is operated in DUAL or PARALLEL mode is to

only use the Speakon-type connector CHANNEL A and to connect one speaker cabinet to pins 1+ and 1–, as described above and the second cabinet to pins 2+ and 2– as shown in illustration. Only pins 2+ and 2– of the Speakon CHANNEL A connector are assigned. Proceeding like this facilitates the cabling of speaker systems that are used in active 2-way operation (Bi-

Amp). The correct connection is also indicated at the amplifiers rear panel.

Owner‘s Manual 9