Phantom Power LED, Connectors and Cables

Operating Manual -1662A Mic/Line Mixer

Power

clipping, detecting excessive signal level on any critical audio path within the master section. If all outputs are turned down and there is still clipping, then one or more inputs needs to be turned down.

4.8 Phantom Power LED

The phantom power switch is on the back panel. When the switch is pressed in, the LED is lit and +48VDC is applied to all six mic inputs for use with condenser microphones. If there is a mix of both condenser and dynamic microphones, the phantom power will not affect the operation of the most dynamic mics. The phantom power voltage ramps up gradually to minimize any turn-on "pops".

5. CONNECTORS AND CABLES

The 1662A mixer is fitted with three types of audio connectors: 3-pin Euroblock assemblies are used for mic/line inputs and main outputs, 1/ 4" tip-ring-sleeve (TRS) phone jacks are used for individual channel insert points, and RCA jacks are used for sum inputs.

Two-conductor (twisted pair) shielded cable is best for all audio connections that use Euroblock assemblies. Belden No. 8412 or its equivalent is an excellent cable due to its heavy

construction. This type of cable should be used for all portable applications. Snake cables containing multiple shielded pairs can be used for a permanent installation, but must be handled very carefully because the leads tend to be fragile, and a broken conductor is difficult to repair.

If low level and high level lines are run parallel for long distances, crosstalk may occur. In fact, the crosstalk (signal leakage between cables) can cause an electronic feedback loop, oscillation, and possibly damage to the equipment. To minimize crosstalk, physically separate low level (microphone) cables from speaker cables by the greatest feasible distance. At any point where cables meet, run low level cables perpendicular to high level or speaker cables. If low and high level or speaker cables must be run parallel and in close proximity to one another, they should be bundled separately. In a permanent installation, avoid running speaker cables and mic cable through the same conduit pipe.