Mackie 24.8Bus Owner's Manual - Page 46

APPENDIX A: Connections "XLR" CONNECTORS Mackie mixers use 3-pin female "XLR" connectors on all microphone inputs, with pin 1 wired to the grounded shield, pin 2 wired to the "hot" (positive polarity) side of the audio signal and pin 3 wired to the "cold" (negative polarity) side of the signal (Figure 7). Use a male "XLR"-type connector, usually found on the nether end of what is called a "mic cable," to connect to these inputs. Mackie occasionally uses 3-pin male "XLRs" for balanced line outputs. The Main L/R Outs on the 8•Bus, for example, are available on XLRs. These are also wired pin 1 ground, pin 2 high and pin 3 low. 1/4" TRS PHONE PLUGS AND JACKS "TRS" stands for Tip-Ring-Sleeve, the three connections available on a "stereo" 1/4" phone jack or plug (Figure 8). TRS jacks and plugs are used in several different applications: • Stereo headphones, and rarely, stereo microphones and stereo line connections. When ADD-ONS SPECS ETC. wired for stereo, a 1/4" TRS jack or plug is connected tip to left, ring to right and sleeve to ground. Mackie mixers do not directly accept 1-plug-type stereo microphones. They must be separated into a left cord and a right cord that are plugged into two channels. • Balanced mono circuits. When wired as a balanced connector, a 1/4" TRS jack or plug is connected tip to signal high, ring to signal low, and sleeve to ground. • Unbalanced Send/Return circuits. When wired as send/ return connector, MONO PLUG Channel Insert jack a 1/4" TRS jack or plug is connected tip to signal send Direct out with no signal interruption to master. Insert only to first "click" (output from mixer), ring to signal return (input back into MONO PLUG mixer), and Channel Insert jack sleeve to ground. Direct out with signal interruption to master. Insert all the way in to the second "click" 1/4" TS PHONE PLUGS AND JACKS STEREO PLUG Channel Insert jack For use as an effects loop. (TIP = SEND to effect, RING = RETURN from effects) "TS" stands for Tip-Sleeve, the two connections available on a "mono" 1/4" phone jack or plug (Figure 9). 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. Some examples: • Unbalanced microphones • Electric guitars and electronic instruments • Unbalanced line-level connections SWITCHED 1/4" PHONE JACKS 1/4" phone jacks can incorporate switches that 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. The Mackie 8•Bus Series uses switches in the channel and bus Insert Jacks, and in the mono/stereo AUX Return Jacks. See Special Mackie Connections on page 45. We also use these switches to ground the inputs of most line level ins/outs when nothing is plugged into them. SLEEVE SLEEVE TIP TIP TIP SLEEVE Figure 9: TS connectors (Plugis Biconnectorus) RING SLEEVE SLEEVE RING TIP TIP RING TIP SLEEVE Figure 8: TRS connectors (Plugis Triconnectorus) Male XLR Female XLR COMMON 2 HOT COLD 3 1 COMMON 1 COLD 3 2 HOT 1 3 2 COMMON COLD HOT Figure 7 (above): XLR connectors (Exelaris Triptipus) Figure 10 (below): RCA connector (Plugis Amateuris) SLEEVE TIP SLEEVE TIP 44