True to the Music
Radial Engineering Ltd.
SW8 Owner’s Manual
Internal Chassis Ground Lift
All connectors are 100% isolated, allowing chassis and signal grounds to be kept separate. However, an internal switch for each
channel is provided to connect the pin-1 cable shields to the chassis without modifying the SW8. By default, this switch is factory set to
open or “lifted” allowing the chassis to “fl oat” ungrounded. Should a specifi c grounding scheme require the cable shields to be bonded
to the chassis, simply set this switch to closed (pushed in position). The switch may be accessed by removing the top cover.
Internal Tone Filter
The SW8 is equipped with a low pass fi lter that may be inserted into the Tone Track signal path to prevent cross-talk from loud Tone
Track signals from bleeding into the program audio. The fi lter is controlled by an internal three position switch that can be accessed
through a hole in the top using a small screwdriver or “tweaker”. The tone fi lter is factory set to OFF or bypass. In most cases it will not
be necessary to engage the fi lter when feeding a Tone Track to the SW8.
The internal switch has three positions:
• Off - the low pass fi lter is not in the signal path.
• Low - high frequencies are reduced by -3dB @ 1k Hz.
• High - high frequencies are reduced by -3dB @ 470 Hz.
+
-
6
Contact Closure Output
This jack accesses an internal relay that acts as an ON/OFF switch for an external circuit. The relay is linked to the front panel ALARM
LED. Normally, the CONTACT CLOSURE OUTPUT relay is in an “open” state preventing current from fl owing through the external
circuit. When the SW8 detects a loss of Tone Track signal the front panel ALARM LED illuminates and the CONTACT CLOSURE
OUTPUT relay closes allowing current to fl ow through the external circuit. An example of an external circuit would be a strobe light or
siren to notify the engineer that the Tone Track signal has disappeared. The CONTACT OUTPUT is designed to work with low voltage
systems between 5 and 24 volts DC.
Linking SW8 Units Together
Several SW8 units can be linked together to accommodate
multi-track systems larger than eight channels. The fi rst
SW8 is designated as the “master” and controls the linked
units as “slaves”. The THRESHOLD control on the master
SW8 adjusts the point at which all units toggle to input
group-B. The A/B SELECT switch on the master unit will
toggle all linked SW8 units. If a remote contact closure
is used, it should be connected to the master SW8 unit’s
CONTACT INPUT. If an external alarm circuit is used, it
should be connected to the CONTACT OUTPUT on the
master SW8.
Linking two or more SW8 units together is accomplished
by simply connecting the LINK OUT on the master SW8 to
the LINK IN on the slaves. Use a standard single conductor
¼” phone cable (¼” guitar cable) to link units. You can
continue the LINK OUT connection to expand the system
as needed.
DC Power Supply
5-12 volts
Master
Slave 1
Slave 2
Tone
Track
Alternate Tone
Track Input
External
Alarm
Remote Contact
Closure
1
-
+
G
-
+
G
2
3
-
+
G
-
+
G
4
5
-
+
G
-
+
G
6
7
-
+
G
-
+
G
8
8
13
Channel-1 ¼”
AUTO SWITCH
Threshold
Detection
Select Toggle
In-A / In-B
DB25 Input Group-A
Tone Filter
High
Low
Off
