Aphex 188 Eight Channel Mic Preamp User Manual

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188

Ground loops hardly ever cause problems within the 188 since it was designed with high

immunity. However, other equipment connected to the 188 may experience hum and noise from

a ground loop. Ground loops can occur when various interconnected equipment is powered from

separate AC circuits that are fed from opposite phases of the power feeder. Most service panels

assign odd numbered breakers to one phase and even to the other. Rooms that are powered from

more than one circuit can have outlets that are out of phase. Adjacent rooms may be powered

with opposite phase.

NOTE: If your system is plagued with ground loop troubles, you should try to get all the

equipment onto the same phase or use a local power isolation transformer.

3.5 MICROPHONE INPUT

The eight transformer coupled microphone INPUT CONNECTORS are locking female 3-pin

XLR’s wired with pin 2 positive.

3.6 OUTPUT CONNECTOR

DB-25 using the TASCAM standard for the eight transformerless impedance balanced

outputs .

DB-25 PIN CONFIGURATION (Analog OUTPUT)

The following chart is a pin configuration for the analog DB-25 connector

This connector pinout matches the Tascam Analog DB-25 connector that has also been adopted

by many other manufacturers such as Mackie and Yamaha. Ready made cables can be purchased

to connect with other products, or to obtain a break-out to XLR plugs.

2 Positive (+)
3 Negative (-)
1 Shield (Ground)

CH1

CH2

CH3

CH4

CH5

CH6

CH7

CH8

(+)

(-)

GND

Female

Male

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Aphex Model 188