Boulder Amplifiers 860 manual Connecting An Unbalanced Source, Ground

CONNECTING AN UNBALANCED SOURCE

Although the input connectors are of the three-pin XLR type, an unbalanced source is easily accommodated by using a special cable. This cable has an RCA phono type connector on the source end and a three- pin XLR connector to go to the input of the 860 Stereo Power Amplifier.

The negative input (Pin 3) should be wired to ground only at the RCA phono connector. This brings the negative input reference of the 860 to the unbalanced source ground, thus reducing ground loops.

Another option for accommodating unbalanced sources is to use Boulder ABL2 Input Adapters. They convert a balanced input into an unbalanced RCA phono input right at the rear of the 860.

Like the above cable, the negative input of the 860 is connected to the ground of the RCA connector. However, the negative side will then share the shield wire with the chassis ground and will not have very good hum rejection.

UNBALANCED INPUT CABLE

2-POS INPUT

3-NEG INPUT

1-GROUND

1-4

GETTING

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