Crestron ST-VC User Manual

This document was prepared and written by the Technical Documentation department at:

Crestron Electronics, Inc.

15 Volvo Drive

Rockleigh, NJ 07647

1-888-CRESTRON

Crestron

ST-VC

Volume Control Module

Contents

Volume Control Module: ST-VC 1

Description.................................................................................................................................1

Leading Specifications...............................................................................................................4

Setup .......................................................................................................................................... 6

Programming ............................................................................................................................. 8

Problem Solving ...................................................................................................................... 11

Return and Warranty Policies..................................................................................................13

Functional Description ................................................................................................1

Models.........................................................................................................................2

Physical Description.................................................................................................... 2

Preparation for Use...................................................................................................... 6

Identity Code ............................................................................................................... 7

Programming with the Crestron AppBuilder...............................................................8

Programming with SIMPL Windows.......................................................................... 8

ST-VC Symbol............................................................................................................9

Example Program......................................................................................................11

Troubleshooting ........................................................................................................11

Further Inquiries........................................................................................................12

Future Updates ..........................................................................................................12

Merchandise Returns / Repair Service ...................................................................... 13

CRESTRON Limited Warranty ................................................................................13

Operations Guide - DOC. 5676A Contents • i

Crestron

ST-VC

Volume Control Module

Volume Control Module: ST-VC

Description

Functional Description

The Volume Control Module is a digitally controlled 3-channel audio attenuator.
Each channel has independent settings for volume, treble, bass, and mute.
Transitions between any attenuation settings are “pop” free. The module is ideally
suited to provide full audio control for systems without an IR-controlled integrated
receiver. Choose a mixer, preamp, and amplifier. Then add a Volume Control
Module to complete the system. In some applications the module's separate control
of treble and bass may even eliminate the need for a graphic equalizer.

Volume, bass, and treble ramp times, scaling, preset levels, and volume muting may
be specified on a per-channel basis (within the specified hardware range). Volume,
bass, and treble are fully independent of each other on each channel. All of these
various aspects are specified in software. Volume, bass, and treble control may be
sent to more than one channel via software so as to support stereo applications.

Input impedance and balance are determined by external connections. Refer to the
diagram below. Input and output are completely independent of each other.
Therefore, it is possible to have a balanced input paired with an unbalanced output
and vice-versa.

Examples of Balanced and Unbalanced External Connections

OPTIONAL 600 OHM

TERMINATOR

+

INX

­+

OUT

-

G

+

INX

­+

OUT

-

G

BALANCED INPUT

BALANCED OUTPUT EXAMPLE

UNBALANCED 10K INPUT

UNBALANCED OUTPUT EXAMPLE

The treble and bass controls are independent from volume and are individually
controlled for each channel. Each channel includes a muting relay with 104 dB
attenuation. When the signal driving MUTEA goes high, the muting circuit is
activated providing 104 dB drop from any preset volume level. Likewise channels

Operations Guide - DOC. 5676A Volume Control Module: ST-VC • 1

Volume Control Module Crestron

“B” and “C” are driving MUTEB and MUTEC, respectively. When the muting
signal goes low, the muting circuit is deactivated and the volume and tone returns to
its original preset level.

NOTE: MUTEALL is an override. All channels are muted when this signal is high.
When it is low, the channels follow the state of MUTEA, MUTEB, and MUTEC.

Each channel is equipped with protective relays that turn ON only after safe
conditions are sustained by the electronic circuitry. This feature protects the output
from “pops” caused by accidental power-down/power-up conditions to the ST-VC.

If the ST-VC is under program control and the power is cycled to the ST-VC, it
renews the volume, bass, and treble levels to the current program settings. The mute
status (per channel and the mute-all) are also restored.

Models

There are two Crestron Volume Control Module configurations available: ST-VC
and STI-VC. Configuration is based on the type of power availability. Use the ST­VC with a 120V power supply and the STI-VC with a 220V power supply. For
purposes of this Operations Guide, the term ST-VC is used for either configuration.

ST-VC

Physical Description

The ST-VC, shown below, is housed in a black enclosure with silk-screened labels
on the front and rear panels. On the front of the unit there are eight LEDs for
indicating the unit’s current status. All connections are made on the back of the unit.
There are four rubber feet on the base of the unit for stability and to prevent
slippage.

ST-VC Physical Views

1.500 in

(3.810 cm)

6.134 in

(15.580 cm)

6.322 in

(16.058 cm)

6.940 in

(17.628 cm)

7.066 in

(17.948 cm)

1.700 in

(4.318 cm)

2 • Volume Control Module: ST-VC Operations Guide - DOC. 5676A