Studio Technologies IFB Plus 2007 - Manual (Page 17)

Model 2 User Guide Issue 9, January 2006
Studio Technologies, Inc. Page 17
9-pin plugs. For reference, the following
chart displays the signals associated with
the access station connector:
Pin # Function
1 Common/Shield
2 Interrupt Audio, CH1 (Model 2 #1)
or CH3 (Model 2 #2)
3 Interrupt Audio, CH2 (Model 2 #1)
or CH4 (Model 2 #2)
4 +18 Vdc (Model 2 #1 and #2)
5 Interrupt Control, CH1 (Model 2 #1)
or CH3 (Model 2 #2)
6 Interrupt Control, CH2 (Model 2 #1)
or CH4 (Model 2 #2)
7 Lamp Voltage, CH1 (Model 2 #1)
or CH3 (Model 2 #2)
8 Lamp Voltage, CH2 (Model 2 #1)
or CH4 (Model 2 #2)
9 Monitor Speaker Mute Control
(Model 2 #1 and #2)
For best performance, a maximum total
cable length of 500 feet should be used to
link Model 24s to the Model 2s. Minimizing
the cable length reduces the total exposure
the unbalanced audio buses have to noise
pickup, etc. Cable runs longer than 500
feet are possible but should be carefully
checked for correct operation.
If more than one Model 24 is going to be
installed some method of “multing” or “split-
ting” the 9-pin D-subminiature connectors
will have to be provided. The simplest meth-
od is to use a short section of ribbon cable
and multiple 9-pin insulations-displacement
(IDC) connectors. Depending on the specific
installation, the “break out” assemblies can
be connected directly to the access station
connectors on the Model 2 units, or can be
“downstream” at one of the Model 24s.
The Model 24 Access Station contains
several configuration switches that must be
set. The input select switch allows the unit to
be set for a mic or a line-level input. In many
cases the Model 11A Gooseneck Micro-
phone, available from Studio Technologies,
will be used with a Model 24. Setting the
switch to the mic position activates the mic
input terminals. The mic input is configured
only for use with unbalanced electret-type
microphones. The + terminal on the mic in-
put provides current limited 5 Vdc to power
the electret microphone. Don’t use a dynam-
ic microphone as damage may occur. The
– terminal is connected to the microphone’s
low signal lead. The connection marked
SHLD is intended for the shield wire of the
microphone cable; it doesn’t carry signal.
The Model 11A Gooseneck Microphone
is an unbalanced electret type, requiring
an external source of DC power. The micro-
phone utilizes a ¼-inch 3-conductor plug
for interconnection. The tip lead brings
DC power to the microphone, as well as
having microphone audio superimposed
on it. The ring lead is microphone com-
mon. The sleeve lead is a shield connection.
Included with the Model 11A is a mounting
hardware kit. Included with the kit is a
¼-inch 3-conductor jack used to mate with
the microphone’s plug. At the factory a
3-conductor wiring harness assembly is
attached to the jack. The wiring harness
has a red-colored wire, a black-colored wire,
and a shield wire. One end of the red wire
is attached to the tip connection on the jack.
The other end should be connected to the
+ terminal on the Model 24’s microphone
input. One end of the black-colored wire
is attached to the ring lead of the jack.
The other end should be connected to the
– terminal on the Model 24’s microphone
input. One end of the shield connection is