Connections
Speakers
70V "Transformer-Coupled" Speakers
The Black Max series was designed to drive only 70V constant volt- age type speaker loads. The use of low-impedance speakers may cause the amplifier to engage its protection circuits and shut down or limit amplifier function. The speaker terminals can accept up to a #10 AWG wire or spade lug and have integral clamping plates which make wiring easier. The polarity of each set of speaker out- puts (A & B) is indicated with a "+" and "-" sign. Use these indica- tors to ensure that the phasing of the speakers are correct. Do not ground the "+" output of either set of outputs. Doing so will cause the amplifier to go into protect mode, shutting down operation of the effected channel.
Note: The "+" and "-" indicators are mirrored on "A" and "B" outputs.
Be sure to make the correct connections.
Earth Ground Terminal
The earth ground terminal is provided as a convenient means to connect to the amplifier’s chassis/AC ground, if necessary. DO NOT connect the earth ground terminal to the "+" terminals of either output. No damage will occur if this is done, but the amplifi- er will go into protect mode and shut down the effected channel.
Inputs
Balanced Input Connections
Balanced input connections are used when the source device provides a balanced output (sig- nal "+", signal "-", and ground "G"). This type of connection is desirable when operating in elec- trically noisy environments, where long input cable runs are needed, or to ensure the lowest noise operation. If compatible with the source device, this type of connection is recommend- ed.
Unbalanced Input Connections
When the source device provides only an unbalanced output (signal and ground), the input should be wired with "-" input shorted to ground (G). The unbalanced signal's shield wire is connected to ground and the signal hot wire is connected to the "+" terminal. Since unbal- anced connections do not provide the same amount of noise immunity that a balanced con- nection does, the connection distances should be made as short as possible.
