IVIE MPS 2300, Руководство пользователя

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Operational
Troubleshooting
lvie Technologies
MPS 2300
Hiss.
Defined as a smooth "shh"t noise. Always a problem with
sensitive, high-gain electronic inputs, and usually starts at
the point of weakest signal (usually the initial mic, phono, or
tape source). Proper gain staging minimizes hiss by
keeping signal below distortion but above the noise floor.
To isolate the source of unwanted hiss, start at the Master
Gain control and work backwards, reducing and then
restoring Gains. You should hear a reduction of hiss
and
audio together at each point, showing the hiss is coming in
earlier. When you find a control which lowers the audio
volume, but not the hiss level, you know the hiss is coming
in after that stage. Assuming that the hiss has not always
been there, this indicates defective electronics.
Crackles.
Defined as a “popcorn” noise. If the crackle persists during
pauses, this indicates defective electronics. Trace using the
procedure shown under Hiss. Crackles which occur during
audio peaks or when the electronics are vibrated usually
indicate bad connections.
Radio Interference.
Defined as unwanted pickup of broadcast or CB radio. The
mic input is more sensitive to RF pickup than the other
inputs. However, if the installer has taken advantage of the
Zone Keys, interference from mic channel will only be
present during actual paging. If Zone Keys are wired “On”
and mic element is turned on/off for paging, mic input is
always active and RF pickup can occur at any time. The
source of RF pickup can be traced by removing each input
in turn until the interference stops. If interference continues
with no inputs, RF is entering through speaker or AC wiring.
Consult factory for assistance.