SSA-424 USER MANUAL 5
1 Description andSpecifications

1.1 GENERAL DESCRIPTION

The SSA-424 Dual Digital Hybrid intervaces two, 2-
wire intercom lines to two, 4-wire intercom lines.
Unlike earlier analog hybrids, the SSA-424 features
advanced digital signal processing to achieve
automatic nulling of the 2-wire lines. Plus, each
hybrid features convenient peak-reading level
meters to quickly match the levels between the lines
that are being interfaced. The result is easy and
accurate setup. With the SSA-424, all need for test
tones, nulling adjustments and ducking adjustments
have been eliminated.
Compatible 2-wire intercom systems include RTS™
TW, Audiocom®, and Clear-Com®. Compatible 4-
wire intercom systems include Telex’s ADAM™,
ADAM™CS, and Zeus™ Digital Matrix Intercom
Systems.
The SSA-424 is also available with optional call
signal interfacing. This option provides bidirectional
call signal compatibility between the 2-wire and 4-
wire intercom systems.
With features like digital signal processing, peak-
reading level meters and optional call signal interfac-
ing, the SSA-424 Dual Digital Hybrid assures ease
of setup and maximum transparency between
intercom systems.

1.2 GENERAL FEATURES

Two Independent Hybrids: Interface two separate
2-wire lines to two separate 4-wire lines.
Automatic Nulling: Digital hybrids eliminate all
nulling and ducking adjustments. Quick, trouble-free
setup. Puts an end to concerns about echo and
feedback when interfacing 2-wire lines.
Peak Reading Level Meters: Quick and accurate
visual audio level adjustment. No extra setup equip-
ment or guesswork is required.
Direct ADAM/Zeus Audio Connection: Accepts
standard ADAM/Zeus DB9 or RJ11 keypanel cables.
Transformer Isolated: All audio inputs and outpus
are transformer isolated to prevent ground loops and
hum.
Call Signal Option: Detects call signals from any of
the compatible 2-wire intercom systems, and then
provides a +5VDC output to the 4-wire intercom
system. Accepts a contact closure input from the 4-
wire system and converts it to the call signal format
required by the 2-wire system. The SSA-424 can be
directly connected to an ADAM, ADAM CS, or Zeus
GPI (General Purpose Interface). GPI inputs can be
programmed to activate call signals and audio paths
to any of the available types of communication within
the 4-wire system, including intercom ports, camera
ISO circuits, IFB circuits, etc. GPI outputs can be set
up to place calls only from a specific keypanel within
the 4-wire system, or from any keypanel within the 4-
wire system that wishes to call the 2-wire system.
Half-rack Wide, 1RU High: Two SSA-424’s fit into a
single rack space. Compatible with RTS TW rack
mount hardware. Can be mixed with other TW
equipment.
Universal Power Pack: Ready for worldwide use.
Automatically accepts any mains voltage from 100-
250 VAC, 50/60 Hz. Power pack equipped with
locking DIN connector for attachment to the SSA-
424.
AUX
J4B
J3B J2B J1B J1A J2A J3A
J4A
AUX
4WIRE SYSTEM 4WIRE SYSTEM
2WIRE SYSTEM
Telex Communications, Inc., Made in U.S.A.
-15 -12 -9 -6 0 +3 +6 +9 +12
LEVEL
SET SYSTEM B
-15 -12 -9 -6 -3 0+3 +6 +9 +12 4W
2W
TO
TO
SSA-424
4W LEVEL
REF SEL
12
BAL
2W CHAN SEL
LEVEL
SET SYSTEM A
-3 4W
2W
TO
TO
POWER
4W LEVEL
REF SEL
12
BAL
2W CHAN SEL 12BAL
OFF
OFF
TM
RTN
+5V RTN
+15V -15V
-15V 0.3A
+15V 1.6A
+5V 3A
J5 POWER
0dB+4dB+8dB
+12dB
-10dB
0dB+4dB+8dB
+12dB
-10dB 12BAL
OFF
OFF
Figure 1. SSA-424 Reference View