Videoquip Phase 3 SD-2 User Manual

SD-2

Silence Detector

Videoquip Research Limited

595 Middlefield Road, Unit #4

Scarborough, Ontario, Canada

M1V 3S2

www.videoquip.com

Introduction

The Phase 3 SD-2 silence detector is a professional audio level monitoring device,
specifically designed to detect silence, or the absence of audio.

Two completely independent channels of detection monitor the two balanced audio
inputs. Each channel has an indicator for the presence of active audio, an adjustable
silence level, and an adjustable delay before silence notification occurs. Gold relay
contacts for each channel allow external devices to be controlled, or may be used to
route active audio for emergency backup audio switching.

The balanced audio connectors are of the XLR type, and the relay connectors are
screw clamp terminal blocks. The SD-2/R rackmount version contains either 1 or 2
SD-2 modules. These modules are identical to the SD-2 version, which is described
throughout this manual.

Installation

The SD-2 consists of 2 completely independent monitoring networks.
Each of the 2 channels provides a female XLR connector for balanced audio input, and
screw clamp terminal blocks for the relay outputs.

Audio Inputs

The audio sources to be monitored are connected to the SD-2 input channels (A,B).
Connect balanced signals as shown in Table 1.

Pin # Function

1 Ground
2 +
3 -

Table 1. XLR Input Connector Pinout

For unbalanced signals, connect the signal to pin 2 (+), and the shield to ground. It is
not necessary to ground pin 3 (-) when using unbalanced signals.

Relay Outputs

Any external devices or audio signals to be controlled by the relays are connected to
the terminal blocks. Two full form-C gold relay contacts are available for each channel,
allowing balanced stereo signals to be controlled. The connections for each relay (from
left to right) are Common, Normally Open (N.O.), and Normally Closed (N.C.). These
are clearly silkscreened on the rear panel.
The normally closed (N.C.) and normally open (N.O.) relay conditions for each channel
exist when audio is present at the channel input (the green signal LED is lit), and
during the adjustable transition delay before a silence alarm occurs (no LEDs lit). The
contacts switch when silence is indicated by the red silence LED for corresponding
channel.