Speakers, Transformer-CoupledSpeaker Connections

Connections

Speakers

Transformer-Coupled Speaker Connections

Transformer-coupled, constant voltage speaker loads are connected to their respective load type (i.e., 70V speakers to the 70V terminal, 25V speaker systems to the 25V terminals) and the COM terminal. Make sure the selector switch is in the TRANS OUT position. A separate 8-ohm ter- minal is provided to drive 8-ohm (low-impedance) speakers through an output transformer tap.

The speaker terminals can accept up to a #10 spade lug and have integral clamping plates that make wiring easier.

4-Ohm Low-Impedance Speaker Connections

A low-impedance (4Ω) speaker load can be driven directly without trans- former coupling by connecting the load to the 4Ω terminal and the GND terminal. Make sure the selector switch is in the DIRECT OUT position.

Bypassing the output transformer and driving the speaker load directly provides the advantage of better bass response. To maximize the power delivered to the speakers, their combined load impedance should be 4 ohms. Connecting higher load impedances is electrically acceptable, but the mismatch in load impedance will cause the speaker load to only receive a portion of the power that the amplifier is capable of delivering. It is not acceptable to connect low-impedance speakers to the 70V and 25V outputs.

Typical connections to a 70V transformer-coupled speaker

Typical connections to a low-impedance (non-transformer-coupled) speaker load

Note jumper link shorting the

GND to the COM terminal.

Note switch is set to TRANS OUT

Note switch is set to DIRECT OUT