Studio Technologies 58 2000 - Manual (Page 23)

Issue 4, December 2000 Model 58/59 User Guide
Page 24 Studio Technologies, Inc.
for Surround
The following procedure would be appro-
priate when an insert section is configured
to place another device in the audio path,
replacing the original. A device commonly
used in this type of application would be a
surround sound encode/decode unit. This
procedure assumes that main input cali-
bration has already been performed. It is
also assumed that calibrated metering
devices are not connected to the meter
outputs.
1. On the first Model 58, connect the
audio level meter to meter output 1.
2. Using the Model 59 Control console,
select input 1 as the audio source.
Confirm that inserts 1 and 2 are dis-
abled. Enable the mute all function,
ensuring that you won’t have to hear
a steady tone during the entire
procedure!
3. Confirm that the audio source con-
nected to main inputs 1 and 2 is gen-
erating a steady signal at precisely its
reference level.
4. Observing the level meter, confirm that
the output level is exactly +4dBu. (If
this is not the case, the main input trim
pot must be re-calibrated.)
5. Using the Model 59 Control Console,
enable insert 1.
6. Observing the level meter, adjust
the trim pot associated with insert 1,
return 1 to give a +4dBu level at
meter output 1.
7. Disconnect the level meter from meter
output 1 and reconnect it to meter
output 2.
8. Repeat steps 4, 5, and 6 for insert 1,
return 2.
9. If insert 2 is being utilized, repeat the
procedure for its two return trim pots.
Once the insert returns on the first Model
58 have been calibrated, repeat the entire
procedure for the additional Model 58
units.
Monitor Output Trim Pots
A trim potentiometer is associated with
each of the two monitor output circuits.
Note that while there are two 2-channel
monitor output connections—A and B—
there are only two output circuits. Relay
contacts are used to switch the output
circuits between the A and B connections.
Installation-specific requirements will
dictate how the monitor output trim pots
need to be adjusted. In most cases the
trim pots will be adjusted to give exactly
the same output level on all the monitor
output channels. Other installations may
require the trim pots to be adjusted in
reference to the outputs of the audio
power amplifiers. For this discussion, we’ll
describe how to match the output levels of
the monitor outputs. Note that this proce-
dure assumes that input calibration has
already been performed.
1. Start by turning off the AC mains
power on all audio power amplifiers.
If loudspeakers with integrated amplifi-
ers are being used, turn them off too.
This “power down” is critical, ensuring
that high-level test signals do not get
sent to the loudspeakers. Don’t mess
around—turn off the amps now!
2. Confirm that all channels associated
with the source connected to input 1
are generating a steady signal at
precisely its reference level.