Technical notes, Model 44 interface – Studio Technologies 212 2006 User Manual
Page 27

Model 212 User Guide
Issue 3, July 2006
Studio Technologies, Inc.
Page 27
fully mute. In addition, rotating the balance 
control to either its fully clockwise or fully 
counterclockwise position will cause the 
applicable channel to fully mute.
Each control has a mechanical step 
(detent) that is located at the halfway 
(50%) position of its rotation range. The 
balance control will typically be set to its 
center, detent position, making the level 
of the left and right channels equal. In an 
ideal installation, the level control can also 
be set to its detent position and provide a 
comfortable headphone output level. This 
will allow the user, in response to their 
preference or a changing environment, 
to adjust the level and balance controls 
as desired. The detent positions will al-
ways remain as a useful reference point. 
To achieve this condition the audio level 
on the connected sources must be ad-
justed as required. Spending a few extra 
minutes “trimming” the connected audio 
signals, rather than just providing what-
ever happens to come up, should prove 
worthwhile. The result will be talent that is 
more relaxed, and an overall production 
that works more smoothly.
Technical Notes
Model 44 Interface
Some applications may benefit from us-
ing the Model 44 Interface which is also 
available from Studio Technologies. The 
single-rack-space unit provides operat-
ing power and digital audio interconnec-
tion for up to six Model 212 Announcer’s 
Consoles. Each Model 212 interconnects 
with an RJ45 port on the Model 44 using a 
single 4-pair “CAT5” or “CAT6” Ethernet-
style cable. One pair of the twisted-pair 
cable supplies 24 volts DC to the Model 
212. Two additional pairs transport digital 
audio to and from the Model 212’s AES3 
interface. A fourth pair is available for 
installer-specified functions. Details about 
the Model 44 are available on the Studio 
Technologies website.
The EtherCon® Connector Card Kit 
(Studio Technologies, Inc. part number 
31207) offers a simple means of preparing 
a Model 212 for use with a Model 44 
Interface and Ethernet-style interface 
cables. This optional card kit is intended 
to be mounted in one of the two spare 
connector openings located on the Model 
212’s back panel. It’s recommended that, 
when viewed from the back, the EtherCon 
kit be mounted on the left side with the 
metal locking tab facing to the left.
Three jumper cable assemblies, provided 
with the EtherCon kit, are used to link the 
Model 212 with the appropriate pairs on 
the EtherCon connector. The Model 212’s 
AES3 output is accessible on 3-pin header 
P8 and should be connected to 3-pin 
header P14 on the EtherCon kit’s printed 
circuit board. The Model 212’s AES3 input 
is accessible on header P9 and should be 
connected to header P15 on the EtherCon 
kit’s printed circuit board. The Model 212’s 
power input is accessible using header 
P3 and should be connected to header 
P13 on the EtherCon kit’s printed circuit 
board.
Once this has been completed standard 
computer-style patch cables can be used 
to link the Model 212 with a port on the 
Model 44 Interface. These cables, often 
called “CAT5” patch cables, are “straight 
through” and organize their four twisted 
pairs as pins 1 and 2, pins 3 and 6, pins 4 
and 5, and pins 7 and 8. For reference the 
EtherCon Connector Card Kit implements 
this interconnection scheme: pins 1 and 2 
