Thanks Bill, I am using J15. I think The dimming outputs are actually on different plugs ?
This is what the manual says:
"Three stereo, balanced, high level (lv RMS typical) are provided. Each output will drive loads of 2K ohms or greater.
The outputs are Dimmed
Monitor (controlled by Mute 1), Muted Monitor (controlled by Mute 2), and Unmuted Monitor. All outputs follow the monitor
selection switches but only the Dimmed Monitor is affected by the front panel monitor level control.
Connectors are located on the Output Board as follows.
Output Board Header Monitor Output
J12 Dimmed Monitor (Mute 1)
J15 Muted Monitor (Mute 2)
J16 Unmuted Monitor"
All monitor outputs are intended to drive external monitor amplifiers. The Dimmed Output, controlled by Mute 1, (which
also mutes the Cue speaker) is intended to feed the control room monitor amplifier where the console is located. When
the Mute 1 bus is enabled, the output from the Dimmed Output will be reduced to a level set by VR13 located on the
Output Board. This level may be set to maximize (for full muting) or, alternatively, to a level just below the feedback
threshold of the speakers.
The Muted Output is intended to feed any other room which that contains microphones connected to the console.
If it is desirable to feed all studios from a common amplifier, this amplifier should be fed from the Unmuted Monitor Output.
External relays driven by the muting contacts on header J7 could then be used to provide the necessary muting of
the signal.