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Installation Considerations

 
 

SHIELDS AND SIGNAL GROUNDING

In the best of all possible worlds, you plug in the input, output and power and Everything sounds GREAT, no problems, and everything is right with the world. Such is not usually the case when interfacing large quantities of equipment in a cogent mess such as a recording studio

control room.

 

The microphone must be shielded.

If it is not, the phantom power

won't work and it will probably hum badly. In fixed installations, please ensure that the only connection to the shield of the microphone is though the signal line that connects it to the unit, and not touching the building steel through the mic box!

The line input should have the shield Source’d at the origination point and the shield should drop at the BA-660. There are internal provisions for supplying a shield source from the BA-660, but this is not recommended.

 

The Insert send sources the shield. The return shield is dropped internally. If this is a problem, correct it by tying the shield to the chassis at the returning signal source.

 

The side chain insert return shield is also floating and should be referenced at the driving source.

REAR PANEL GROUND CONECTIONS

Rear Panel Ground connections There are two 5 way binding posts on the rear of the unit. The green one is attached directly to the chassis, and the Black one is tied directly to Tech Earth internally. The link that is provided external to the chassis is the only point that the chassis and Tech Earth, (Audio Common) are brought together. This connection must be maintained either through the link or via the studio wiring. Your technical consultant will be your best guide to determining the correct installation method for your room.

 

Shields and the output. The shield at the Line Output is carried from pin 1. This is the source of the shield for the output wire, but should not be carried through the input of the driven load.

INPUT AND OUTPUT BALANACE

Both the Mic, Line, insert return, side chain insert and the Line Output circuits are

balanced and floating. The Insert send is balance

 

When taking a single ended input, always bring the grounded line to ground at the signal source. This will treat the line as a balanced line and reduce the hum induction.

 

The output of this device must be brought to ground at pin 1 of the  output connector if it is to be unbalanced. The output mode switch must be switched to the correct position. In un-balanced operation, if the switch is in the wrong position the unit will either have no output or it will oscillate.

 

When taking the insert send to an unbalanced input it is imperative that the low side be disconnected from the ring and tied to the sleeve at the BA-660. The output drive is not ground current sensing, and should not drive ground. This WILL oscillate when driving ground.

!DANGER!

Fuse location and Input power voltage selection. The fuse is located directly behind the IEC Power input connector. There are two internal switches with which the input voltage range can be set to accommodate anything between 90 and 250 VAC. Please leave this adjustment to qualified personnel.

 

When in doubt, call the factory!