42
“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 hal-
lowed standards
dictated by the
AES (Audio
Engineering
Society).
Use a male
“XLR”-type con-
nector, usually found on the nether end of
what is called a “mic cable,” to connect to a
female XLR jack.
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:
• 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.
APPENDIX B: CONNECTIONS
• 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).
1
⁄
4
" TS PHONE PLUGS AND JACKS
“TS” stands for Tip-Sleeve, the two connec-
tions available on a “mono”
1
⁄
4
" phone jack or
plug (Figure C). TS jacks and plugs are used in
many different applications, always unbalanced.
The tip is connected to the audio signal and the
sleeve to ground (earth). Some examples:
• Unbalanced microphones
• Electric guitars and electronic instruments
• Unbalanced line-level connections
SWITCHED
1
⁄
4
" PHONE JACKS
Switches can be incorporated into
1
⁄
4
"
phone jacks, which are activated by inserting
the plug. These switches may open an insert
loop in a circuit, change the input routing of
the signal or serve other functions. Mackie
uses switches in the channel insert and bus
insert jacks, input jacks and AUX returns. We
also use these switches to ground the line-level
inputs when nothing is plugged into them.
In most cases, the plug must be inserted fully
to activate the switch. Mackie takes advantage
of this in some circuits, specifying circum-
stances where you are to insert the plug only
partially. See
Special Mackie Connections
,
later in this section.
2
2
3
1
1
SHIELD
COLD
HOT
SHIELD
COLD
HOT
3
SHIELD
COLD
HOT
3
2
1
Figure A: XLR Connectors
SLEEVE
TIP
SLEEVE
TIP
RING
RING
TIP
SLEEVE
RING
Figure B:
1
⁄
4
" TRS Plugs
SLEEVE
TIP
TIP
SLEEVE
TIP
SLEEVE
Figure C: TS Plug
