MACKIE LM-3204 - Manual (Page 30)

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APPENDIX A: Connections
• Stereo Headphones, and rarely, stereo
microphones and stereo line connections.
When wired for stereo, a
1 ⁄ 4 " TRS jack or
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
1 ⁄
4
" TRS jack to two male
XLR plugs, one for the Right signal and one
for the Left.
• Balanced mono circuits. When wired as a
balanced connector, a 1 ⁄ 4 " TRS jack or plug
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 1 ⁄ 4 "
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).
“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
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.
1 ⁄
4
" TRS PHONE PLUGS AND JACKS
“TRS” stands for Tip-Ring-Sleeve, the
three connections available on a “stereo” 1 ⁄ 4 "
or “balanced” phone jack or plug. See Figure
B. TRS jacks and plugs are used in several
different applications:
2
3
1
HOT
COLD
COMMON
COMMON
COLD HOT
COMMON
COLD HOT
Figure A:
XLR Connectors
SLEEVE
TIP SLEEVE
TIP
RING
RING
TIP
SLEEVE RING
Figure B: 1/4” TRS plugs