Studio Technologies 220 2013 User Manual
Page 35

Model 220 User Guide
Issue 5, February 2013
Studio Technologies, Inc.
Page 35
part number 0850-0114 specifies crimp
terminals that are appropriate for wires of
22 to 30 gauge. These parts are available
worldwide from sources such as Digi-Key,
website www.digikey.com.
To make the process of connecting to the
Model 220’s headers a simple task an
interface cable kit, part number 31087,
is available from Studio Technologies.
Each kit includes five cable assemblies
and a length of heat-shrinkable tubing.
Each cable assembly consists of a mating
connector with three color-coded wires
attached. These wires, approximately 12
inches in length, allow convenient solder-
ing to a connector slated to be installed in
a spare location on the Model 220’s back
panel. For reference, the wire color for pin
1 is gray, pin 2 is yellow, and pin 3 is blue.
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 disas-
sembled prior to installing connectors in
the spare locations. Four hex-head ma-
chine 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, remain-
ing attached by means of a flexible cable
assembly. This “flexible” assembly links
the main printed circuit board assembly
with the board assembly that contains the
pushbuttons 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 lo-
cated close to their related input or output
connectors. 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
common, 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 electrically 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.