Radial Engineering SW8-USB Users Manual

True to the Music

SW8-USB

Auto-Switcher and USB Playback Interface

Radial Engineering Ltd.
1588 Kebet Way, Port Coquitlam BC V3C 5M5
tel: [phone] • fax: [phone]

www.radialeng.com

email: [e-mail] • web: www.radialeng.com

Specications and appearance are subject to change without notice.
Copyright © 2019 Radial Engineering Ltd.

Owner’s Manual

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Radial SW8-USB Owner’s Manual

Table of Contents

Overview..................................................................................................2

Features ..................................................................................................3-4

Powering the SW8-USB ..........................................................................5

Connecting the primary and backup computers ...................................... 5

Setting the digital audio resolution and selecting outputs........................6

Connecting the analog audio outputs ...................................................... 6

Operating in manual switch mode ...........................................................7

Using the JR-2 remote footswitch............................................................7

Auto-Switch mode overview ....................................................................8

Sending Tone via SPDIF to the Auto-Switch inputs .................................8

Sending MTC to the Auto-Switch inputs ..................................................8

Operating in Auto-Switch mode ...............................................................9

Synchronizing playback computers overview ..........................................10

Using the Start/Stop footswitch remote ...................................................10

Using an external MIDI device.................................................................10

Using the Sync Lock feature....................................................................11

Using the Alarm output ............................................................................ 12

Synchronizing multiple SW8-USB units...................................................12

Troubleshooting guide ............................................................................. 13-14

Warranty .................................................................................................. Back Cover

INTRODUCTION

Thank you for purchasing the SW8-USB, a unique backing track switcher and USB playback interface
that allows you to connect two computers to a professional audio system for playback, with the ability
to switch to the backup computer in an instant should a fault occur on the primary playback machine.

We encourage you to read through this manual to familiarize yourself with the many features available
on the SW8-USB, allowing you to get the most out of this powerful interface and auto-switching device. If
you have any questions not answered in this user guide, please visit our website at www.radialeng.com
for additional resources and frequently asked questions.

PERFORMANCE DISCLAIMER

!

The Radial SW8-USB is an electronic device designed to provide the means to backup other electronic
devices. However, like all electronics, the SW8 itself is not totally immune to malfunction. Because the
SW8 is designed to integrate with other devices to form a complete system, a critical malfunction may
not be obvious until the system is asked to perform. This makes it very important to test your complete
playback system before each performance to ensure your system is working as expected.

Radial Engineering Ltd. will not be held liable for any consequential or inconsequential costs or
damages associated with the use of the SW8-USB. It is understood that connecting, testing and
operating the SW8-USB, along with the application or misapplication, is the sole responsibility of the
end user. For more details refer to the Radial limited warranty.

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True to the Music

OVERVIEW

The SW8-USB is an eight channel switching device designed primarily for live concerts where backing tracks are
used to reinforce the performance. Should your primary playback source suffer a failure or dropout, the SW8-USB
can switch to a backup source to prevent any negative effects on the performance. This switching can be done
automatically by the SW8-USB, or it can be performed manually using a switch on the front panel or by remote
control.

Typical playback systems require a computer as the digital audio source, along with an audio interface in order
to provide analog audio outputs to feed the PA system. For a redundant playback system, the list of equipment
required is doubled: two computers, and two audio interfaces to pair with them. One of the advantages that the
SW8-USB provides over this typical setup is that it allows you to connect directly to your playback computers
over USB, eliminating the need for additional audio interfaces which in turn reduces the weight and cost of your
redundant system.

The SW8-USB is equipped with Type-B USB connectors and 24bit/192kHz digital audio converters that provide
eight channels of high quality audio playback over balanced XLR outputs. Designed to feed the PA system, these
mic-level outputs are transformer isolated to eliminate noise from ground loops, and they can also be set to line­level operation. Additional line-level outputs are provided for local monitoring of your playback signals, with the
choice of DB25 or 1/4” TRS connections.

In addition to passing audio over USB, the SW8-USB is also able to function as a MIDI interface: providing you
with the ability to use the SW8-USB with show control systems to trigger lighting or video cues, or to control and
synchronize audio playback on your primary and backup computers. For larger shows that require more than eight
channels of audio playback, up to three SW8-USB units can be linked together for a total of 24 output channels.

Typical stage setup for playing backing tracks through the SW8-USB

Front of House (FOH)

Primary Computer (A)Backup Computer (B) JR-2 Remote

Radial Engineering Ltd. SW8-USB™ Owner’s Manual

Playback System

Control

(Optional)

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True to the Music

FRONT PANEL FEATURES

1 2 3 4 5 6 7 8 9 10 11

1. PSU A/B: Dual LEDs indicate that the SW8-USB is receiving power from each power supply. Only one connection is
required to power the SW8-USB, the other is provided for redundancy to eliminate loss of power.

2. MIC/LINE: Recessed switch determines whether the front panel XLRs are mic-level or line-level outputs. When set to mic (out
position), the XLR outputs are also transformer-isolated to reduce noise from ground loops. Red LED illuminates when set to line­ level operation.

3. AUTO: Recessed switch determines whether the SW8-USB switching is controlled manually by the user or set to Auto-Switch
mode where the SW8-USB will automatically select the B inputs should a fault be detected on the A side. Press in to engage Auto­ switch mode, the LED below will illuminate.

4. PLAYBACK ACTIVITY: Dual green LEDs illuminate to indicate that the SW8-USB is receiving MTC or tone via SPDIF - depending
on the Auto-Switch Input setting on the rear panel of the SW8-USB. Note that these LEDs will not light to signal audio playback.

5. MUTE: Latching switch with red LED indicator to mute the analog outputs of the SW8-USB. This will silence the XLR outputs, but
signal will still pass through the DB25 and TRS outputs on the rear panel, to allow for local signal monitoring.

6. STANDBY: Latching switch with ashing red LED indicator to direct the SW8-USB to hold on input A when in Auto-Switch mode,
regardless of whether MTC or tone via SPDIF is being received. This feature can also be activated remotely using the optional
JR-2 footswitch (by pressing MUTE on the JR-2).

7. INPUT SELECT: Latching switch allows you to select the active USB inputs. Green LED indicator for USB card A, amber LED
for USB card B. This switch is deactivated when the SW8-USB is in Auto-Switch mode, or when the optional JR-2 footswitch is
connected.

8. RESET: This momentary switch is used after a fault is detected, allowing the SW8-USB to switch back to the A inputs. Always
check that the Playback Activity A LED is illuminated (indicating good MTC or tone via SPDIF is being received) before pressing
this switch. (Used in Auto-Switch mode only)

9. ALARM: Flashing red LED indicator illuminates when a fault is detected on the primary playback computer (A), showing that the
SW8-USB is now playing back from the backup computer (B).

10. XLR OUTPUTS: Analog audio outputs playback from your primary or backup computer depending on the input select assignment.
These will output mic-level or line-level signals depending on the setting of the MIC/LINE switch.

11. GROUND LIFT: Lifts pin-1 on the XLR output to help eliminate hum and buzz from ground loops.

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Radial Engineering Ltd. SW8-USB™ Owner’s Manual

True to the Music

REAR PANEL FEATURES

12 13 14 15 16 17 18 19 20 21

12. PSU A & B INPUTS: Connections for locking 4-pin power supplies (included). The PSUs for the SW8-USB are switching
supplies to allow for easy international usage.

13. MIDI IN/OUT: Allow you to to pass MIDI signal to and from the computer on the active USB connection. When SYNC LOCK is
disengaged, signal sent to the MIDI IN feeds both the primary and backup computers at once, allowing you to use an external MIDI
controller to trigger playback on both computers simultaneously.

14. SYNC LOCK: When engaged, this switch makes it possible to pass MIDI information from the primary computer to the backup
computer to allow for syncronized playback. Disengaging this switch allows an external MIDI controller or a footswich connected to
the START/STOP input to trigger playback on both computers simultaneously.

15. USB A & B: Type-B USB connections to directly connect your primary and backup playback computers for up to eight channels of
analog audio playback per SW8-USB. Compatible with Mac OS only, featuring 192kHz/24bit converters.

16. AUTO-SWITCH INPUT: Selects whether Tone via SPDIF or MTC is used for the auto-switch inputs of the SW8-USB. Tone (SPDIF)
should be used for the lowest latency when switching over to the B inputs.

17. START/STOP: 1/4” TRS connection allows you to send stop/start MMC signals to your computers to control and synchronize
playback. Can be used with standard contact closure footswitches such as the JR1-M remote footswitch.

18. DB25 OUTPUTS: Line-level outputs 1-8 over a DB25 multipin connection. These outputs are always active regardless of the
setting of the front panel MUTE switch, and they will follow the primary or backup computer along with the main XLR outputs.

19. 1/4” TRS OUTPUTS: Balanced output jacks are wired in parallel with the DB25 monitor outputs. These outputs operate at
line-level and will always be active regardless of the MUTE switch setting on the front panel.

20. JR-2 FOOTSWITCH INPUTS: XLR and 1/4” TRS connections allow the optional JR-2 remote footswitch to control the switching
and Standby functions of the SW8-USB. Standard 1/4” TS contact-closure footswitches and MIDI controllers with switching outputs
can also be used to select between the primary and backup computers.

21. ALARM: 1/4” TS connection from an internal relay can be used to turn on an external beacon when a dropout is detected at the
auto-switch input for computer A. This output can also be used to link multiple SW8-USB units together simultaneously.

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