Grounding/Earthing Procedures (Curing Hums) - BSS Audio FDS 310 User Manual

21.0 Grounding/Earthing Procedures
(Curing hums)
The FDS-310 is supplied with the signal ground (0V) tied to chassis, which is
connected in turn to:
• Mains ground (earth).
• Other equipment chassis' in the rack.
If the FDS-310 outputs are connected to amplifiers with unbalanced inputs, it
will normally be necessary to disconnect the internal ground link, to prevent
ground-loop hums. Refer to section 22.4 for information on this procedure:
Since the FDS-310 has balanced inputs and outputs, and because there is no
input ground connection, it is very unlikely that any connection problem will
be experienced, provided the wiring instruction in sections 9 & 10 have been
correctly followed. If the system has a very loud hum and buzzing, we
recommend that you check the input signal leads have their cable shields
properly grounded at the source end (that is at the output socket of the unit
that is connected to the FDS-310s input). If the hum is moderate and slightly
'raspy', we recommend that you check the incoming AC supply is greater
than 90V RMS. Hum can also be induced by radiation from large power
transformers (See section 8).
Grounding/Earthing
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