| |
Meter Bridge Connector Pinouts
The 8-bus series of mixers provide connectors for connecting the Mackie
8-bus meter bridge. The connectors are 0.100" DIP header pinouts and are
normally hidden under rubber removable plugs across the top of the mixer,
just below the insert jacks. These pinouts were determined experimentally,
using an oscilloscope, a multimeter, a 1KHz test tone source, and a small
DIP20 to DIP20 header cable to make probing for signals easier.
![[20 pin DIP header]](header20.jpg)
Channels (1-8, 9-16, 17-24, 25-32)
The channel strip audio signals appear to be 1.30V peak 0.92V RMS
at 0dB reading on the meters with the channel soloed. This was determined
with a 1KHz sine wave input to a channel strip line-level input. The
channel was soloed, the fader set to unity gain, and the input trim adjusted
to read 0dB on the VU meter.
| Pin |
Function |
| 1 | Tape Return 1, 9, 17, 25 |
| 2 | Tape Return 2, 10, 18, 26 |
| 3 | Tape Return 3, 11, 19, 27 |
| 4 | Tape Return 4, 12, 20, 28 |
| 5 | Channel Strip Post-Fader 4, 12, 20, 28 |
| 6 | Channel Strip Post-Fader 3, 11, 19, 27 |
| 7 | Channel Strip Post-Fader 2, 10, 18, 26 |
| 8 | Channel Strip Post-Fader 1, 9, 17, 25 |
| 9 | +18VDC |
| 10 | -18VDC |
| 11 | +5VDC |
| 12 | GND |
| 13 | Channel Strip Post-Fader 8, 16, 24, 32 |
| 14 | Channel Strip Post-Fader 7, 15, 23, 31 |
| 15 | Channel Strip Post-Fader 6, 14, 22, 30 |
| 16 | Channel Strip Post-Fader 5, 13, 21, 29 |
| 17 | Tape Return 5, 13, 21, 29 |
| 18 | Tape Return 6, 14, 22, 30 |
| 19 | Tape Return 7, 15, 23, 31 |
| 20 | Tape Return 8, 16, 24, 32 |
Output Section
The main Left and Right output signals appear to be +4dBu (1.23V RMS,
1.76V peak w/1KHz sine wave).
| Pin |
Function |
| 1 | Right Main Output |
| 2 | Left Main Output |
| 3 | NC |
| 4 | NC |
| 5 | +5VDC |
| 6 | GND |
| 7 | NC |
| 8 | NC |
| 9 | +18VDC |
| 10 | -18VDC |
| 11 | NC |
| 12 | NC |
| 13 | NC |
| 14 | NC |
| 15 | NC |
| 16 | NC |
| 17 | NC |
| 18 | NC |
| 19 | NC |
| 20 | NC |
|
|
