875Z - EIGHT CHANNEL POWER AMPLIFIER
875Z REAR PANEL CONNECTORS & SWITCHES
The following is a description of the rear panel switches for the 875 Zone Amplifier and their function. There are 8 x 75 watt amplifiers in the 875B Zone amp. The channels are split into 4 zones each with 2 channels. Each zone will operate in stereo or the channel outputs may be connected in series to achieve a mono channel of 250 watts. Both channels in each zone have 4 input options
1) ODD NUMBERED CHANNEL INPUT SELECTORS (Channels 1, 3, 5 or 7):
This four position slide switch selects input signals for this channel and, in SERIES (bridged) mode, it is the sole input used for the combined channel 1+2, 3+4, 5+6 or 7+8 amplifier channel.
P | 1st position (top): | left stereo bus |
P | 2nd position: | right stereo bus |
P | 3rd position: | sum of left and right stereo bus (mono of stereo bus) |
P4th position (bottom): direct input from RCA jack. (.875 v = 75watts/8ohms)
EVEN NUMBERED CHANNEL INPUT SELECTOR:
Similar to above INPUT SELECTOR SWITCH but only controls the input to channel 2, 4, 6 or 8 when the pair of adjacent channels is in STEREO mode. In SERIES mode this switch has no effect.
2)STEREO BUS INPUTS:
2
3)STEREO/SERIES SWITCH:
Controls the two channels in this zone.
P | STEREO (top position): | individual channels |
P | SERIES (bottom position): | bridged mode wherein channels 1+2 (using only Ch1 input), or channels 3+4 |
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| (using only Ch3 input) or channels 5+6 (using only Ch5 input) or channels 7+8 |
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| (using only Ch7 input) are combined into a single, higher power channels. |
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| Sensitivity in SERIES mode = 1.8v input at 250 watts output into 8ohms |
4)CHANNEL DIRECT INPUT CONNECTORS: Sensitivity: 875mV for an output of 75watts into 8ohms
5)CHANNEL LEVEL CONTROL:
Normal or maximum is fully clockwise. Minimum is fully counter clockwise which fully attenuates the input signal.
6)SPEAKER BINDING POST CONNECTORS:
P | STEREO mode: | Use the red terminal to feed the + red terminal on the loudspeaker. |
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| Use the black terminal to feed the - black terminal on the loudspeaker |
P | SERIES mode: | Use the Ch1 red terminal to feed the + red terminal on the loudspeaker and Use the |
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| Ch2 red terminal to feed the - black terminal on the loudspeaker |
7)MUTE OPTIONS SWITCH: P ON (Left position):
P SIG (Centre position): P EXT (Right position):
Each zone has individual muting options.
Zone will remain on as long as power is on in the amplifier.
Mutes the Zone when the signal is absent for more than 8 minutes.
Zone will mute when 12v is present at the External Zone Mute connector (9).
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