Mackie M1200 Owner's Manual - Page 33

APPENDIX C: Connectors "XLR" CONNECTORS Mackie amplifiers use 3-pin female "XLR" connectors on each input, 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 above-board and in full SHIELD 2 HOT COLD 3 1 SHIELD 1 Figure A: XLR Connectors COLD 3 2 HOT 1 3 2 SHIELD COLD HOT 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. 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 (Figure B). TRS jacks and plugs are used in several different applications: RING SLEEVE SLEEVE RING TIP TIP Figure B: 1⁄4" TRS Plugs RING (COLD) TIP (HOT) SLEEVE (SHIELD) • Stereo Headphones, 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). • Unbalanced Send/Return circuits. When wired as a 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). • 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). This is the application used for the inputs to Mackie amplifiers. 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 (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 or speaker-level connections Figure C: TS Plug SLEEVE TIP SLEEVE TIP TIP (HOT) SLEEVE (SHIELD) UNBALANCING A LINE In most studio, stage, and sound reinforcement situations, there is a combination of balanced and unbalanced inputs and outputs on the various pieces of equipment. This usually will not be a problem in making connections. • When connecting a balanced output to an unbalanced input, be sure the signal high (hot) connections are wired to each other, and that the balanced signal low (cold) goes to the ground (earth) connection at the unbalanced input. In most cases, the balanced ground will also be connected to the ground at the unbalanced input. If there are ground-loop problems, this connection may be left disconnected at the balanced end. • When connecting an unbalanced output to a balanced input, be sure that the signal high (hot) connections are wired to each 33