Appendix A: Connections - Mackie LM-3204 Owner's Manual

APPENDIX A: Connections

"XLR" CONNECTORS
Mackie mixers use 3-pin female "XLR" con-
nectors on all microphone inputs, with pin 1
wired to the grounded (earthed) shield, pin 2
wired to the "high" ("hot" or positive polarity)
side of the audio signal and pin 3 wired to the
"low" ("cold" or negative polarity) side of the
signal (Figure A). All totally aboveboard and in
Figure A:
XLR Connectors
full accord with the hallowed standards dic-
tated by the AES (Audio Engineering Society).
Use a male "XLR"-type connector, usually
found on the nether end of what is called a
"mic cable," to connect to these inputs.
⁄ " TRS PHONE PLUGS AND JACKS
1
4
"TRS" stands for Tip-Ring-Sleeve, the
three connections available on a "stereo"
or "balanced" phone jack or plug. See Figure
B. TRS jacks and plugs are used in several
different applications:
Figure B: 1/4" TRS plugs
30
COMMON
COLD HOT
COMMON
COLD HOT
HOT
2
COLD
3
1
COMMON
RING SLEEVE SLEEVE RING TIP
TIP
RING
TIP
SLEEVE
• Stereo Headphones, and rarely, stereo
microphones and stereo line connections.
When wired for stereo, a
plug is connected tip to left, ring to right
and sleeve to ground (earth). Mackie
mixers do not directly accept 1-plug-type
stereo microphones. They must be separated
into a left cord and a right cord which are
plugged into the two mic preamps.
You can cook up your own adapter for a
stereo microphone adapter. "Y" two cables
out of a female
XLR plugs, one for the Right signal and one
for the Left.
• Balanced mono circuits. When wired as a
balanced connector, a
is connected tip to signal high (hot), ring
to signal low (cold), and sleeve to ground
(earth).
• Unbalanced Send/Return circuits. When
wired as send/return "Y" connector, a
TRS jack or plug is connected tip to signal
send (output from mixer), ring to signal
return (input back into mixer), and sleeve
to ground (earth).
1 ⁄ "
4
1 ⁄ " TRS jack or
4
1 ⁄ " TRS jack to two male
4
1 ⁄ " TRS jack or plug
4
1 ⁄ "
4