Boulder Amplifiers 865 manual Connecting AN Unbalanced Source

CONNECTING AN UNBALANCED SOURCE

Although the inputs are all of the 3-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 3-pin connector (for an input) at the 865 Integrated 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 865 to the unbalanced source ground, thus reducing ground loops.

Another option for accommodating unbalanced sources is that of the Boulder ABL2 input adapter. It converts a balanced XLR input into a RCA connector input right at the rear of the 865. Please contact your dealer for information regarding the ABL2 Input Adapter.

Like the above cable, the negative input of the 865 is connected to the ground of the RCA connector. However, this negative side will then share the shield wire with the chassis ground and will not have the best hum rejection.

UNBALANCED INPUT CABLE

2-POS INPUT

3-NEG INPUT

1-GROUND

1-5

GETTING

STARTED