Mackie lm3204 User Manual

• 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).

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.

“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: