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2. ~ac mains relay switch
The AC mains switch turns the amplifier completely off by disconnecting the supervisory power supply from the AC mains. Since this small supervisory supply controls the main power supply access to AC power, shutting down the supervi- sory power supply also disconnects the main supply from AC.
3. balanced input
Receives balanced audio input from the associated preamplifier. One XLR connector is available.
For best performance, use balanced connections whenever possible. Refer to the illustration below and to the associated preamplifier documentation to ensure that Nº33H XLR input pin assignments correspond to the associated preamplifier XLR output pin assignments. If not, wire the cable so that the appropriate input pin connects to the appropriate output pin.
Pin 1: Signal ground
Pin 2: Signal +
Pin 3: Signal – (inverting)
Connector ground lug: chassis ground
Note
Before making balanced connections, remove the
4. single-ended input
Receives unbalanced audio input from a preamplifier with sin-
If the associated preamplifier does not support balanced connections, connect the RCA output on the preamplifier to the RCA input on the Nº33H. To reduce the chance of noise at the (otherwise unterminated) inverting XLR input, insert the supplied