Studio Technologies 55 1996 - Manual (Page 27)

Model 55/56 User Guide Issue 3, December 1996
Studio Technologies, Inc. Page 27
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 prob-
lem. 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 re-
pair.
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.
Intermittent Audio Connections
Should you experience audio connections
that seem to be “flaky” or intermittent, refer
to the Technical Notes section of this
guide. The ¼-inch 3-conductor phone
jacks used on the StudioComm products
are of very high quality, conforming to the
industry standard EIA RS-453. Some
plugs do not meet this standard, specifi-
cally in the shape of the tip conductor. In
rare cases you may have to replace plugs
on interconnecting cables or headphones
to remedy an interconnection problem.
Switchcraft No. 297 or Neutrik NP3C
phone plugs will function correctly.
Clicks in the Audio
As covered in the Configuration section of