Kramer Electronics Ltd.
Congratulations on your purchase of this Kramer Switcher. Since 1981 Kramer has been dedicated to the
development and manufacture of high quality video/audio equipment. The Kramer line has become an
integral part of many of the best production and presentation facilities around the world. In recent years,
Kramer has redesigned and upgraded most of the line, making the best even better. Kramer’s line of
professional video/audio electronics is one of the most versatile and complete available, and is a true
leader in terms of quality, workmanship, price/performance ratio and innovation. In addition to the Kramer
line of high quality switchers, such as the one you have just purchased, Kramer also offers a full line of
high quality distribution amplifiers, processors, interfaces, controllers and computer-related products.
This manual includes configuration, operation and option information for the following Kramer switchers.
They are grouped here as they are similar in operation and features.
VS-55 – 5x1 Dual Wideband Switcher
VS-55A – 5x1 Stereo Audio Switcher
VS-55V – 5x1 Video Switcher
VS-55YC – 5x1 s-Video Switcher
A Word on Video Switchers
Switchers route one or more sources signals to one or more users. They vary in the number of inputs,
programming capability, number of outputs, operating format (audio, composite video, component, etc.)
and switching method (i.e., whether they switch during the vertical interval or not, whether they are
electronic, RS-232 or mechanically controlled). A switcher usually switches between several sources
(inputs) and one or more acceptors (outputs). A switcher that allows several inputs to be connected to
several outputs simultaneously is called a matrix switcher. Switchers may be of the electronic or
mechanical type. Most matrices are of the active electronic type, with many crosspoints. Vertical Interval
Switching, frequently used in video, ensures that the transition from one video source to another is smooth
and without interference. The switchers described in this manual are electronic switchers, have full
specifications, various control options and expandability and can be rack-mounted using special adapters.
Most of them offer a simple and economic solution for every video, audio or wideband-signal application.
Factors Affecting Quality of Results
There are many factors affecting the quality of results when signals are transmitted from a source to an
Connection cables - Low quality cables are susceptible to interference; they degrade signal quality
due to poor matching and cause elevated noise levels. They should therefore be of the best quality.
Sockets and connectors of the sources and acceptors - So often ignored, they should be of
highest quality, since "Zero Ohm" connection resistance is the objective. Sockets and connectors
also must match the required impedance (75ohm in video). Cheap, low quality connectors tend to
rust, thus causing breaks in the signal path.
Amplifying circuitry - Must have quality performance when high linearity, low distortion and low
noise operation are the desired end result.
Distance between sources and acceptors - Plays a major role in the result. For long distances
(over 15 meters) between sources and acceptors, special measures should be taken in order to avoid
cable losses. These include using higher quality cables or adding line amplifiers.
Interference from neighboring electrical appliances - These can have an adverse effect on signal
quality. Balanced audio lines are less prone to interference, but unbalanced audio should be
installed far from any mains power cables, electric motors, transmitters, etc. even when the cables