Studio Technologies 220 2008 - Manual (Page 35)

Model 220 User Guide Issue 4, October 2008
Studio Technologies, Inc. Page 35
The heat-shrinkable tubing is provided so
that the connector solder cups can be in-
sulated from each other. It will also provide
some strain relief to the solder joints. Be
certain to slip the desired length of tubing
over the wire prior to soldering a connec-
tion! (If the writer had a dollar for every time
he forgot to put tubing on a wire (or slip on
a connector shell) before making a solder
connection…)
The Model 220’s enclosure must be
disassembled prior to installing connectors
in the spare locations. Four hex-head
machine screws, two on the bottom front
of the enclosure and two on the back panel,
must be removed. A 5/64-inch hex driver
is required. The cover can then be care-
fully separated from the chassis, remaining
attached by means of a flexible cable as-
sembly. This “flex-cable” assembly links the
main printed circuit board assembly with the
board assembly that contains the pushbut-
tons and LED indicators. Ensure that the
flex cable is not damaged while the Model
220 is being customized. For easier access,
the pushbutton/LED board assembly can
also be easily removed.
The 3-position headers on the Model 220’s
main circuit board assembly are located
close to their related input or output con-
nectors. The following list provides the
printed circuit board reference numbers
and associated functions:
P4: Headphone output, pin 1 common,
pin 2 tip (left), pin 3 ring (right).
P5: Microphone input, pin 1 shield, pin 2
high, pin 3 low. Follows back-panel 3-pin
female XLR pin assignment.
P6: Main output, pin 1 shield, pin 2 high,
pin 3 low. Careful! Back-panel 3-pin male
XLR has pin 1 floating, pin 2 high, pin 3 low.
P7: Talkback output 1, pin 1 shield, pin 2
high, pin 3 low. Careful! Back-panel 3-pin
male XLR has pin 1 floating, pin 2 high,
pin 3 low.
P8: Talkback output 2, pin 1 shield, pin 2
high, pin 3 low. Careful! Back-panel 3-pin
male XLR has pin 1 floating, pin 2 high,
pin 3 low.
P11: IFB input, pin 1 common, pin 2 DC
with channel 1 audio, pin 3 channel 2 audio.
Follows back-panel 3-pin female XLR pin
assignment.
P13: External 24 volt DC input, pin 1 com-
mon, pin 2 +24 volts, pin 3 not used. Back-
panel 2.1 x 5.5 mm jack has +24 volts on
center pin. Header P12 is used by the back-
panel 24VDC jack assembly and is electri-
cally in parallel with P13.
P14: Line input 1, pin 1 common, pin 2
high, pin 3 low.
P15: Line input 2, pin 1 common, pin 2
high, pin 3 low.
Additional functions can be accessed using
these 3-position headers:
P9: Auxiliary relay contact B, pin 1 normally
closed, pin 2 common, pin 3 normally open.
P10: Auxiliary relay contact A, pin 1
normally closed, pin 2 common, pin 3
normally open.
P17: Remote switch connections, pin 1
common, pin 2 talkback 1 button, pin 3
talkback 2 button.
P18: Remote switch connections, pin 1
common, pin 2 main out button, pin 3
auxiliary (currently not supported in
software).
P20: Pushbutton backlighting, pin 1
common, pin 2 button lamps, pin 3
current limited 24 volts from external
24 volt DC input.