Kramer VA-4 User manual

KRAMER ELECTRONICS LTD.
USER MANUAL
MODEL:
VA-4
Dual Channel Balanced Stereo
Audio Amplifier
P/N: 2900-000004 Rev 2A

VA-4 – Contents i
Contents
1Introduction 1
2Getting Started 2
2.1 Achieving the Best Performance 2
2.2 Safety Instructions 2
2.3 Recycling Kramer Products 3
3Overview 4
3.1 Defining the VA-4 Dual Channel Balanced Stereo Audio Amplifier 4
4Connecting the VA-4 7
4.1 Connecting to the VA-4 via RS-232 8
5Technical Specifications 10
6Protocol 2000 11
Figures
UFigure 1: VA-4 Dual Channel Balanced Stereo Audio Amplifier Front PanelU5
UFigure 2: VA-4 Dual Channel Balanced Stereo Audio Amplifier Rear PanelU6
UFigure 3: Connecting the VA-4 Dual Channel Balanced Stereo Audio AmplifierU8
UFigure 4: Crossed Cable RS-232 ConnectionU9
UFigure 5: Straight Cable RS-232 Connection with a Null Modem AdapterU9

VA-4 - Introduction 1
1 Introduction
Welcome to Kramer Electronics! Since 1981, Kramer Electronics has been
providing a world of unique, creative, and affordable solutions to the vast range of
problems that confront video, audio, presentation, and broadcasting professionals
on a daily basis. In recent years, we have redesigned and upgraded most of our
line, making the best even better!
Our 1,000-plus different models now appear in 11 groups that are clearly defined
by function: GROUP 1: Distribution Amplifiers; GROUP 2: Switchers and Routers;
GROUP 3: Control Systems; GROUP 4: Format/Standards Converters; GROUP 5:
Range Extenders and Repeaters; GROUP 6: Specialty AV Products; GROUP 7:
Scan Converters and Scalers; GROUP 8: Cables and Connectors; GROUP 9:
Room Connectivity; GROUP 10: Accessories and Rack Adapters and GROUP 11:
Sierra Products.
Congratulations on purchasing your Kramer VA-4 Dual Channel Balanced Stereo
Audio Amplifier, which is ideal for the following typical applications:
•Presentation audio level control
•Recording studios and broadcast studios for on-line signal distribution

2 VA-4 - Getting Started
2 Getting Started
We recommend that you:
•Unpack the equipment carefully and save the original box and packaging
materials for possible future shipment
•Review the contents of this user manual
•Use Kramer high performance high resolution cables
Go to http://www.kramerelectronics.com to check for up-to-date user
manuals, application programs, and to check if firmware upgrades are
available (where appropriate).
2.1 Achieving the Best Performance
To achieve the best performance:
•Use only good quality connection cables to avoid interference, deterioration
in signal quality due to poor matching, and elevated noise levels (often
associated with low quality cables)
•Do not secure the cables in tight bundles or roll the slack into tight coils
•Avoid interference from neighboring electrical appliances that may adversely
influence signal quality
•Position your Kramer VA-4 away from moisture, excessive sunlight and dust
This equipment is to be used only inside a building. It may only be
connected to other equipment that is installed inside a building.
2.2 Safety Instructions
Caution: No operator serviceable parts inside the unit
Warning: You use only the power cord that is supplied with the
unit. Do not open the unit. High voltages can cause
electrical shock! Servicing by qualified personnel only.
Warning: Disconnect the power and unplug the unit from the wall
before installing
i
!
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VA-4 - Getting Started 3
2.3 Recycling Kramer Products
The Waste Electrical and Electronic Equipment (WEEE) Directive 2002/96/EC
aims to reduce the amount of WEEE sent for disposal to landfill or incineration by
requiring it to be collected and recycled. To comply with the WEEE Directive,
Kramer Electronics has made arrangements with the European Advanced
Recycling Network (EARN) and will cover any costs of treatment, recycling and
recovery of waste Kramer Electronics branded equipment on arrival at the EARN
facility. For details of Kramer’s recycling arrangements in your particular country
go to our recycling pages at http://www.kramerelectronics.com/support/recycling/.

4 VA-4 - Overview
3 Overview
The VA−4 is a volume controller for two channels of balanced stereo audio signals
on XLR connectors. The volume of each stereo channel can be adjusted
independently of the other stereo channel.
The VA-4:
•Features a digitally controlled volume control function
•Uses high quality low distortion audio components, enabling transparent
processing of the audio signals
•Lets you control the audio gain of each channel via the front panel or via
RS-232
•Includes a bright 7-segment LED display on the front panel, showing the
current gain or attenuation setting
•Stores settings in the non-volatile memory upon shut down
3.1 Defining the VA-4 Dual Channel Balanced Stereo Audio
Amplifier
This section defines the VA-4.

VA-4 - Overview 5
VA-4 – Overview 5
Figure 1: VA-4 Dual Channel Balanced Stereo Audio Amplifier Front Panel
# Feature Function
1 POWER Switch Illuminated switch supplying power to the unit
2 - Button Press to decrease the level
3 + Button Press to increase the level
4 LEVEL 7-segment LED Display Shows the gain of the selected channel (in decibels)
5 SELECT Button Selects the stereo channel (1 or 2) being controlled using the + button and the - button
6 Channel 1 LED Illuminates when channel 1 is chosen via the SELECT button
7 Channel 2 LED Illuminates when channel 2 is chosen via the SELECT button

6 VA-4 - Overview
Figure 2: VA-4 Dual Channel Balanced Stereo Audio Amplifier Rear Panel
#
Feature
Function
8 CH.1 IN LEFT and RIGHT XLR Female Connectors Connects to the balanced stereo audio source 1
9 CH.2 IN LEFT and RIGHT XLR Female Connectors Connects to the balanced stereo audio source 2
10 CH.1 OUT LEFT and RIGHT XLR Male Connectors Connects to the balanced stereo audio acceptor 1
11 CH.2 OUT LEFT and RIGHT XLR Male Connectors Connects to the balanced stereo audio acceptor 2
12 RS-232 9-pin D-sub Port Connects to the PC or the Remote Controller
13 Power Connector with FUSE AC connector enabling power supply to the unit
6VA-4 – Overview

VA-4 - Connecting the VA-4 7
4 Connecting the VA-4
Always switch off the power to each device before connecting it to your
VA-4. After connecting your VA-4, connect its power and then switch
on the power to each device.
To connect the VA-4 as illustrated in the example in Figure 3:
1. Connect a balanced stereo audio source (for example, a set top box: source
1) to the left and right channel 1 IN XLR connectors.
2. Connect a balanced stereo audio source (Source 2) to the left and right
channel 2 IN XLR connectors.
3. Connect the left and right channel 1 OUT XLR connectors to a balanced
stereo audio acceptor (Acceptor 1).
4. Connect the left and right channel 2 OUT XLR connectors to a balanced
stereo audio acceptor (Acceptor 2).
5. Connect a PC (or other control device) to the RS-232 9-pn D-sub port, if
control via RS-232 is required (see Section 4.1
6. Connect the power cord to the mains electricity (not shown in
).
Figure 3).
7. Select the stereo channel (1 or 2) by pressing the SELECT button, and set
the level using the + and – buttons (as required).
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