Studio Technologies 55 2002 - Manual (Page 27)

Model 55/56 User Guide Issue 4, June 2002
Studio Technologies, Inc. Page 27
The Over Current LED will light if the
power source that supplies the Model 56
Control Console is loaded to exceed its
maximum output current. The most com-
mon reason for an over current condition
would be a shorted 5-conductor MIDI-style
interconnecting cable. A major fault in the
Model 56 would also cause the LED to
light.
The Over Current LED will also light if the
talent amplifier output is loaded to exceed
its maximum output current. The most
common reason for an over current condi-
tion would be a shorted interconnecting
cable. Also, connecting more than the
specified maximum of four Model 35 or
Model 38 Talent Amplifiers can also cause
the LED to light. Possible, but not likely,
would be a fault condition in a Model 35
or Model 38.
If the Over Current LED does light, trouble-
shooting should prove quite simple. Begin
by disconnecting the cables that are
plugged into the Control Console/MIDI In
and the talent amplifier output connectors.
Perform the disconnection directly on the
Model 55’s back panel. The LED should
stop lighting. Now reconnect to Control
Console/MIDI In. If the LED again lights,
follow this paragraph. If the LED does not
light, skip to the next paragraph. Check the
interconnecting cable that links the Model
55 with the Model 56 Control Console.
You need to determine where the short
circuit condition is located. The Model 55
will not be damaged if the Over Current
LED is lighting so you should use it to help
you locate the fault. In just a few minutes
you should be able to isolate exactly if the
cable or the Model 56 is causing the
problem. Replace the cable if it proves
to be bad—remember you’ll need a
MIDI-style cable with all five conductors
connected. If the Model 56 appears to be
at fault, it will need to be returned to the
factory for repair.
If the LED did not light when you recon-
nected to Control Console/MIDI In, recon-
nect to the talent amplifier output. The LED
should now light, identifying that the prob-
lem is with the talent amplifiers or associ-
ated cabling. In most cases you will find
that a cable is at fault. If a talent amplifier
is found to be at fault, it will need to be
returned to the factory for repair.
Input Data LED
The Input Data LED lights only when data
is received that is valid for the Model 55.
The Model 55 uses MIDI system-exclusive
messages to perform all operations. When
the Model 56 Control Console is con-
nected to the Model 55, the LED will light
any time the Model 56 generates data.
This is because the Model 56 will only
generate data that is compatible with the
Model 55.
If you are not using the Model 56, and
instead are supplying MIDI data using
another device, the LED should prove
extremely useful when troubleshooting.
Only when the MIDI data conforms to the
Model 55’s MIDI system-exclusive format
will the LED light. Refer to Appendix A,
located at the end of this guide, for details
on how data must be sent to the Model 55.
Clicks in the Audio
As covered in the Configuration section of
the manual, the four stereo line inputs can
be configured for –10dBV or +4dBu op-
eration. Setting an input for –10dBV, while
connecting an audio source with a +4dBu