Niles Audio MVC100R, MVC100 User Manual

I N S T A L L A T I O N G U I D E

HIGH-POWER MUTING STEREO VOLUME CONTROL

MVC100 MVC100R

CONGRATULATIONS!

Thank you for choosing MVC 100 High-Power Muting Stereo Volume Control from Niles. With proper installation and
operation, you should enjoy years of trouble-free use. Niles manufactures the industry’s most complete line of custom
installation components and accessories for audio/video systems. To see the complete Niles product assortment, visit us
on the Internet at: www.nilesaudio.com

TABLE OF CONTENTS

Introduction 1

Features and Benefits

Installation Considerations

Installation

11

Operation 16

Specifications

18

Contents 19

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INTRODUCTION

The MVC 100 is a high power, muting stereo speaker volume control that connects between the speaker-level output of an
amplifier, speaker selector, or a Niles VCS HUB4 distribution hub and a pair of speakers.

A perfect application for the MVC 100 is adjusting the volume of, or muting and unmuting remotely located speakers.
The MVC 100 adjusts the volume of speakers connected to it by attenuating the amplifier signal. To assure minimal
dissipation of internal power with

virtually no power wasted as heat, Niles volume controls use autoformers instead of L-pads as the volume­controlling element.

The MVC 100 is an impedance-magnifying (IM) volume control. Unlike other brands, it has additional autoformer windings
that magnify the impedance of connected speakers, while allowing all 12 steps to adjust the volume of the sound. Switches
on the PC board select these windings.

With the volume control providing impedance protection for your amplifier, you can create systems with no additional
impedance-matching devices between the volume control and the amplifier.

In a typical application of IM controls, a system has eight pairs of 8-ohm speakers throughout the house and in outdoor loca
tions. Connect each pair of speakers to an MVC 100/R volume control with its switch in the 8x position, eliminating the need
for an external impedance-matching device to protect the amplifier. Even when playing all eight speaker pairs at once, the
amplifier runs at normal operating temperatures.

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FEATURES AND BENEFITS

The MVC 100 offers a number of improvements over other volume controls:

• Interchangeable Decora-style inserts for fast, easy color change. Inserts and knobs (sold separately) are available
in a variety of colors.

• A universal impedance-magnifying design enables the MVC 100 to act as both a stereo and an impedance mag­nifying volume control. You can magnify the speakers’ impedance by a factor of two, four, or eight.

• Unlike other impedance-matching volume-control products, Niles IM volume controls maintain a 12-position
adjustment regardless of how much impedance magnification you use, with total attenuation >48dB.

• Pop-free switching between all steps.

• Precision autoformers provide superior sonic performance, exceeding the audio quality of non-impedance magni­fying volume controls.

• Isolated left and right-channel grounds ensure safety with any amplifier.

• May be used with 4-, 6-, or 8-ohm speaker systems.

• Automuting fuction enabled by 12VDC.

• Programmable to turn on with muting engaged or disabled.

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FEATURES AND BENEFITS (CONTINUED)

• Ideal for home and commercial sound installations.

• UL rated to comply with all local building codes.

• Available colors: almond, black, bone, brown, and white.

• Installation requires only a screwdriver and wire stripper.

• Mounting depth of only 2-9/16". Fits into standard 18-cubic-inch one-gang junction boxes.

• Power handling: 100W/channel RMS.

• Frequency response: 20Hz to 20kHz ±2dB.

• Ten years parts and labor warranty.

NOTE: SOME SPEAKERS HAVE SELECTABLE IMPEDANCE. BEFORE YOU PROCEED, PLEASE CONFIRM THAT ANY

SELECTABLE-IMPEDANCE SPEAKERS IN YOUR SYSTEM ARE PROPERLY SET FOR THE SYSTEM YOU ARE INSTALLING.

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INSTALLATION CONSIDERATIONS

CALCULATING THE IMPEDANCE MAGNIFICATION SETTING

Use the following instructions and the accompanying charts to select the correct switch setting for the number and type of
speakers in your system.

CAUTION! EVERY SPEAKER PAIR IN THE SYSTEM MUST BE CONNECTED TO AN IMPEDANCE-MAGNIFYING VOLUME
CONTROL AND SET TO THE SAME MAGNIFICATION.

1. Count the number of pairs of 4-ohm speakers and the number of pairs of 8-ohm speakers you are connectin Count
pairs of 6-ohm speakers as 4-ohm pairs.

2. Determine whether the amplifier should see a 4-ohm load or an 8-ohm load. This information is typically found in
the owner’s manual of the amplifier.

3. Read the correct switch position from the charts on page 7. See
See Figure 5 if your amplifier must have an 8-ohm speaker load.

4. Set the switches on all of the controls to the same position (1x, 2x, 4x, or 8x). See Figure 7.INSTALLATION

Figure 4 if your amplifier can drive a 4-ohm load.

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INSTALLATION CONSIDERATIONS (CONTINUED)

LIMITATIONS IN VOLUME WITH HIGH MAGNIFICATION SETTINGS

Using an 8x setting limits the power to each speaker pair to one-eighth of the amplifier’s output.

In a typical application of IM volume controls, a system has eight pairs of 8-ohm speakers throughout the house and in
adjacent outdoor locations. Each pair of speakers is connected to an IM volume control with its switches set for 8x.

With eight pairs of speakers, one-eighth of the amplifier’s power is available to any pair. Therefore, an amplifier rated at
100W per channel RMS into 8 ohms will deliver up to 12.5W to each of the eight pairs – whether you play all eight pairs or
just one pair. This translates into a drop in the maximum volume capability of about 9dB at the 8x setting.

TOOLS REQUIRED

• 1/8" Standard Slotted Screwdriver

• 1/4" Standard Slotted Screwdriver

• Wire Stripper

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INSTALLATION CONSIDERATIONS (CONTINUED)

USING SPEAKER SELECTORS WITH IM VOLUME CONTROLS

Although IM controls provide volume and on/off at the volume-control location, they do not give you central control of speak­ers playing throughout the house.

Speaker-selection systems give you central control, but some speaker selectors have non-defeatable impedance-protection
circuits. Combining IM controls with such a selector will reduce your maximum volume substantially. To solve this problem,
specify a speaker selector with a defeatable protection circuit (Niles models HPS4, HPS6, SS-4, or SS-6). Keep the protection
circuit off at all times.

JUNCTION BOXES

The mounting depth of the MVC 100 is 2-9/16". When installed, the unit extends 2-1/16" behind the sheetrock wall
(assuming 1/2" sheetrock). For installation, use a standard 18-cubic-inch (or larger) junction box. Suitable junction boxes
are available from your Niles dealer or local electrical-supply company.

TYPE OF SPEAKER WIRE

We recommend 16-gauge stranded copper speaker wire for most connections, and 14-gauge wire for runs longer than 80
feet. Don’t use speaker wire larger than 14 gauge, because larger wire may not fit into the connectors. Never use solid-core,

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