Mackie 32.8Bus Owner's Manual - Page 47

TIP (RETURN) "Y" insert cable RING (IN) TIP (OUT) RING TIP (RETURN) (SEND) TIP (SEND) FROM PROCESSOR OUTPUT TO MIXER CHANNEL INSERT TO PROCESSOR INPUT Figure 11 : Hybrid connector with Send & Return combined on a TRS plug with the separate Send & Return on the TS plug ends (Plugis Insertis Hybridus) In most cases, the plug must be inserted fully to activate the switch. Mackie takes advantage of this in some circuits, specifying circumstances where you are only to partially insert the plug. Once again, see Special Mackie Connections, on the next page. RCA PLUGS AND JACKS RCA "phono" plugs and jacks are often used in home stereo and video equipment and in many other applications (Figure 10). 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 or shield to the surrounding "basket." There are no RCA jacks on the Mackie 8•Bus Series Mixing Consoles. Adapters to convert an RCA male plug to male 1/4" TS plug are available at any electronic shop, like Radio Shack. UNBALANCING A LINE In most studios, there is a mix 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 connections at each end are wired together, and the balanced signal low goes to the ground 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 hum or radio frequency ground-loop problems, this connection may be left disconnected at the unbalanced end. • When connecting an unbalanced output to a balanced input, be sure that the signal high connections at each end are wired together. The unbalanced ground connection should be wired to the low and the ground connections of the balanced input. If there are ground-loop problems, try connecting the unbalanced ground connection only to the input low connection, and leaving the input ground connection disconnected. In some cases, you will have to make up special adapters to interconnect your equipment. For example, you may need a balanced XLR female connected to an unbalanced 1/4" TS phone plug. SPECIAL MACKIE CONNECTIONS The balanced-to-unbalanced connection has been anticipated in the wiring of the Mackie 8•Bus Series jacks. A 1/4" TS plug inserted into a 1/4" TRS balanced input, for example, will automatically unbalance the input and make all the right connections. Conversely, a 1/4" TRS plug inserted into a 1/4" unbalanced input will automatically tie the ring (low) to ground. TRS Send/Return Insert Jacks The Insert Jacks on both the 8•Bus input channels and on the Submaster and Main Mix buses are the three-conductor, TRS type 1/4" phone. They are unbalanced, but have both the mixer output (send) and the mixer input (return) signals in one connector (Figure 11 above). The sleeve is the common ground for both signals. The send from the mixer to the external unit is carried on the tip, and the return from the external unit to the mixer is on the ring. Using the Send Only on an Insert Jack If you insert a TS (mono) 1/4" plug only partially (to the first "click") into an 8•Bus Series Insert Jack, the plug will not activate the jack switch and will not open the insert loop in the circuit. This allows you to borrow the channel or bus signal at that point in the circuit, without interrupting normal operation. Note: Do not overload or short-circuit the signal you are tapping from the mixer. That will affect the internal signal in the 8•Bus Series. 45 ADD-ONS SPECS ETC.