3.2 Battery Operation 24 V DC
The amplifier DPA 4411 can either be operated on the AC mains or connected to an external 24 V battery
power source. Switching to battery operation is accomplished via internal relay.
The battery has to be connected to the corresponding socket (23) on the rear panel of the appliance using
insulated AMP flat connectors 6.3x0.8 mm. The amplifier is protected against confusion of poles.
Additional internal protection is provided through two miniature fuses – F502 and F503 – one per each
conductor (+ and -), which are located on the printed board assembly 85272 (see paragraph 12, diagram
11). For the DPA 4411 the battery cable’s diameter should be at least 2.5 mm
2
and the cable length for
the single distance should not exceed 4.0 m (max. drop in voltage < 1V).
Caution
Operation of the DPA 4411 is solely allowable using batteries without grounding or
batteries with grounding of the negative pole. Operation with batteries with grounding of
the positive pole is not permissible.
4. Inputs INPUT 1 to INPUT 4
The inputs INPUT 1 to INPUT 4 (15) are electronically balanced. With a sensitivity of 775mV = 0dBu they
are meant for the connection of control amplifiers. For the case that floating inputs are needed, the inputs
are prepared for retrofitting input transformers.
Note
If a switch-contact is located between the control amplifier output and the power amplifier
input, switch clicks might become audible during switching. If this is the case, incorporating
input transformers (NRS 90208 - one per input) can solve the problem (see paragraph 9.3)
Parallel operation of INPUT 1 to INPUT 4 (15) is possible when using the ROUTING
switches (16). This allows to connect the input signal through to feed several power
amplifiers with the identical program. Use a permanent marker pen to mark the
needed setting of the ROUTING switches (16) next to the ROUTING switch
push-button symbol.
diagram 1
input socket connection
diagram 2 LF-cable for coupled operation of two DPA 4411
24
