Appendix B: Connections

“XLR” Connectors

Mackie mixers use 3-pin female “XLR” connectors 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. See Figure A. This is all totally above board and in full accord with the hallowed standards dictated 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 a female XLR jack.

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.

•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).

Manual Owner’s

SHIELD 2

HOT

COLD 3 1

SHIELD 1

COLD 3 2

HOT

1SHIELD

3COLD

2HOT

Figure A: XLR Connectors

1⁄4" TS Phone Plugs and Jacks

“TS” stands for Tip-Sleeve, the two connections available on a “mono” 1⁄4" phone jack or plug. See Figure C.

SLEEVE

SLEEVE

TIP

TIP

TIP

SLEEVE

Figure C: TS Plug

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.

RING SLEEVE

SLEEVE RING TIP

TIP

RING

TIP

SLEEVE

Figure B: 1⁄4" TRS Plugs

TRS jacks and plugs are used in several different ap- plications:

•Balanced mono circuits. When wired as a bal- anced connector, a 1⁄4" TRS jack or plug is con- nected tip to signal high (hot), ring to signal low (cold), and sleeve to ground (earth).

•Stereo Headphones, and rarely, stereo micro- phones 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.

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

•Speaker connections

Don’t use guitar cords for speaker cables! They’re not designed to handle speaker-level signals and could overheat.

RCA Plugs and Jacks

RCA-type plugs (also known as phono plugs) and jacks are often used in home stereo and video equipment and in many other applications (Figure D). They are unbalanced and electrically identical to a 1⁄4" TS phone plug or jack. Connect the signal to the center post and the ground (earth) or shield to the surrounding “basket.”

SLEEVE TIP SLEEVE TIP

Figure D: RCA Plug

 

Owner’s Manual

25