Studio Technologies 41 2007 - Manual (Page 16)

Issue 2, February 2007 Model 41 User Guide
Page 16 Studio Technologies, Inc.
state will be stored in non-volatile memory.
Specifically, the channel selected for audio
monitoring and the status of the auto scan
function will be recorded. This ensures
that upon subsequent “power up” the unit
will return to how it was left. If, for ex-
ample, the auto scan function was active
when the Model 41 was powered down,
auto scan will begin once mains power is
again connected.
Troubleshooting
If you’re having trouble getting the Model
41 up and running, this section may help.
If you haven’t read the previous sections
of this guide, you should do so before
proceeding.
If the Model 41 Doesn’t Work
At All
A source of AC mains power must be
connected to the Model 41. The unit
is a “universal input” type so that ap-
plying anything between 100 and 230
volts, 50/60 Hz is acceptable. Whenever
mains power is connected the four moni-
tor status LEDs should go through their
power-up routine, lighting one at a time in
sequence. If this does not occur confirm
that AC mains power is active (“hot”) and
that the cord is securely mated with the
inlet connector on the Model 41’s back
panel.
In all foreseeable situations, both normal
and abnormal, the status LEDs should
go through the normal power-up routine.
However, it’s possible that if all four IFB
circuits are being presented with a short-
circuit condition, the internal 36 volt power
supply may enter its protection mode and
shut down. In this case no LED will light.
If this scenario occurs, even after confirm-
ing that mains power is correctly being
applied, try removing the loads from the
IFB circuits. The easiest way to do this is
to remove the 3-pin female XLR-type con-
nectors that are plugged into the Model
41’s back panel. If normal operation then
begins, carefully check the IFB circuit wir-
ing for fault conditions.
If the status LEDs still don’t go through
their power-up routine, even after con-
firming that mains power is present and
that the IFB circuits are not shorted, it’s
likely that the unit requires factory service.
For safety in the event of a major internal
failure, the internal 36 volt power supply
contains a fuse in series with the incoming
mains power. This fuse will open (“blow”)
only if a serious failure occurs inside the
unit. The fuse is not field-replaceable.
The Model 41 must be returned to the
factory, or an authorized service location,
for review and repair.
Maintaining Correct Input
Signal Levels
The Model 41’s four 2-channel audio
inputs are designed for nominal signal
levels of +4 dBu. Applying signal levels
significantly lower than +4 dBu will re-
duce the signal-to-noise ratio (raising the
perceived noise floor) and can prevent
the connected user devices from oper-
ating optimally. Applying signal levels
significantly higher than +4 dBu will re-
duce the headroom and greatly increase
the chance of reaching audio “clipping.”
Obviously, these cautions are not unique
to the Model 41, but apply to most audio
equipment. The front-panel level meters
provide an easy means of confirming that
the Model 41 is being presented with the
correct audio levels.