Inter-m R-150 User manual

R-150/R-300/R-500
Reference Series Amplifier
Copyright 2004 Inter-M Corporation

R-150/R-300/R-500 Reference Series Amplifier
Contents
Welcome ..................................................................................................................................... 3
Unpacking ............................................................................................................................... 3
Warnings .................................................................................................................................. 3
Operation................................................................................................................................. 5
Features ....................................................................................................................................... 6
Front Panel Controls.................................................................................................................... 7
Operational Modes .................................................................................................................. 11
Speaker Impedance and Connections .............................................................................. 11
Speaker Connection Procedures............................................................................................ 12
Speaker Cable ...................................................................................................................... 13
Maintaining Proper Polarity .................................................................................................. 13
Rack Mounting Your Amplifier ............................................................................................. 13
Block Diagram .......................................................................................................................... 14
Specifications............................................................................................................................ 15
2

R-150/R-300/R-500 Reference Series Amplifier
Welcome
A personal welcome to you from the management and employees of Inter-M
Thank you for purchasing this fine Inter-M product. All of us here at Inter-M are dedicated
to providing you with the highest quality products and the best value.
We sincerely trust this product will provide you with years of satisfactory service, but if
anything is not to your complete satisfaction, we will endeavor to make things right.
Welcome to Inter-M, and thank you for becoming a part of our worldwide extended
family!
Unpacking
Although your R-150/R-300/R-500 Reference Series Amplifier is neither complicated nor
difficult to operate, we recommend you take a few minutes to read this brief manual
and familiarize yourself with the important information regarding product features, setup
and operation.
As with most electronic devices, we strongly recommend you retain the original
packaging. In the unlikely event the product must be returned for servicing, the original
packaging (or reasonable equivalent) is required.
Warnings
Environment
Never place this product in an environment that could alter its performance or reduce its
service life. Such environments are usually characterized by high levels of heat, dust,
moisture, or vibration.
Safety
1. Read these instructions carefully.
2. Follow all instructions.
3. Keep all warnings.
4. Do not operate this apparatus near water.
5. Clean only with a damp cloth.
6. Do not block any of the ventilation openings.
7. Install only in accordance with the instructions in this manual.
3

R-150/R-300/R-500 Reference Series Amplifier
8. Do not install near any heat sources such as radiators, heat registers, stoves, or other
devices (including amplifiers) that produce heat.
9. Do not defeat the safety purpose of the polarized or grounding type plug. A polarized
plug has two blades, with one wider than the other. A grounding type plug has two
blades and a third grounding prong. The wide blade or the third prong is provided for
your safety. If the provided plug does not fit into your outlet, consult an electrician for
replacement of the obsolete outlet.
10. Protect the power cord from being walked on or pinched, particularly at plugs,
convenience receptacles, and the point where it is attached to the apparatus.
11. Use only the attachments/accessories specified.
12. Use only with a cart, stand, tripod, bracket, or table specified, or sold with the
apparatus. When a cart is used, use caution when moving the cart/apparatus
combination to avoid overturning.
13. Unplug this apparatus during lightning storms or when unused for long periods of time.
14. Refer all servicing to qualified service personnel. Servicing is required when the
apparatus has been damaged in any way, such as power supply cord or plug is
damaged, liquid has been spilled or objects have fallen into the apparatus, the
apparatus has been exposed to rain or moisture, does not operate normally, or has been
dropped.
4

R-150/R-300/R-500 Reference Series Amplifier
Operation
Make certain that speakers and input sources are properly connected before switching
AC Mains power on.
Keep volume levels at minimum gain before switching on.
NOTE: The system’s operation is delayed by approximately three seconds after pressing
the AC Mains power switch. This is due to the built-in protection circuitry, designed to
protect speakers and other system components.
5

R-150/R-300/R-500 Reference Series Amplifier
R-150/R-300/R-500
Power Amplifier
Features
High Performance Monitor Amp
• Studio quality monitor amp provides clean sound for the studio, conference room,
concert hall and commercial installations.
Advanced Protection Circuitry
• Thermal and current overload protection, short and open circuit protection, power-
on delay, for component and loudspeaker protection.
Ultra-Efficient Cooling System
• Convection cooling uses no fan, providing ultra-quiet performance in critical
applications.
Bridged Mono and Input Parallel Operation
• Bridged mono and input parallel modes for increased power and versatility.
Versatile Connectivity
• Balanced and unbalanced inputs on XLR and 1/4” phone connectors, as well as
speaker connect and five-way binding post output connectors to accommodate a
wide array of system options.
LED Indicators
• Front panel LED indicators show power, clip, protection and level status.
6

R-150/R-300/R-500 Reference Series Amplifier
Front Panel Controls
1. Power Switch
Pushing this switch up swiches the unit on. Pushing it down swiches the unit off.
2. Power Indicator LED
When the unit is switched on, the Power LED will glow steadily.
3. Protection Indicators
There are two protection indicator LEDs – one LED for Channel 1 of the amplifier
and one LED for Channel 2. These LEDs indicate the state of the amplifier’s
protection circuitry. When the Protection LED is on (illuminated), the protection
circuitry is active, indicating that the unit is not operating normally. This is typically
due to overheating or power limiting. Please check the Input and Output
condition of the amplifier.
(Note that the Protection Indicators light for approximately six seconds when the
amplifier is first switched on.)
The amplifier offers the following modes of protection:
Thermal Protection: Activates when internal operating temperature exceeds 100˚
Celsius.
Compressor/Limiting: When maximum output power is reached, output level will
be reduced to avoid distortion.
DC Fault Protection: DC detection circuitry shuts the speaker output when a DC
fault voltage of ±3dB or greater is detected.
Power On/Off Muting: Audio to speakers is delayed for several seconds on
powering on and off to reduce potential speaker damage from transients.
7

R-150/R-300/R-500 Reference Series Amplifier
4. Input Attenuators
These are detented controls for regulating each channel’s input level. Clockwise
rotation increases gain.
5. Handles
Use these handles to easily move the amplifier.
6. Clip Indicators
The red CLIP LED indicates an excessive output level, lighting when distortion
reaches approximately 1%. Do not operate the unit with the CLIP LED steadily
illuminated.
7. Output Level Indicators
The LEVEL LED indicates the amplifier’s output status, lighting when audio signal
reaches –15dB.
8

R-150/R-300/R-500 Reference Series Amplifier
Rear Panel Controls
1. Speaker Output Terminals
These five-way binding posts and speaker connect jacks are used to connect
speakers to the unit.
Speakers may be connected in Stereo or Bridged Mono mode. Please refer to the
illustrations below. When connecting speakers in Bridged Mono mode, use the
Channel 1 “+“ output for the positive lead, and the Channel 2 “+“ for the
negative lead.
2. AC Connector
Connect the supplied standard AC input cable here.
3. Mono/Stereo Mode Selector
Use this slide switch to select either Stereo or Bridged Mono operation. When
Bridged Mono mode is selected, only Channel 1 is active. Use the Channel 1
Input Attenuator to set input level, and refer to the corresponding indicator LEDs
for operating status.
9

R-150/R-300/R-500 Reference Series Amplifier
4. Input Connectors
Balanced input connectors are provided on XLR jacks, while unbalanced
connections can be made using the 1/4” phone jacks. (When operating in
Bridged Mono mode, only Channel 1 input is active.)
5. Heat Sink
Heat is emitted via the external HEAT SINK when the amplifier is switched on.
When the amplifier is rack mounted, we recommend that you keep the rear of
the rack open in order to release heat.
10

R-150/R-300/R-500 Reference Series Amplifier
Operational Modes
Stereo Mode
In Stereo mode, channels A and B operate independently, with each channel feeding its
own amplifier circuit. In this mode, minimum speaker impedance per channel is 4.
Bridged Mono Mode
In Bridged Mono mode, both amplifier channels are bridged together and function as a
single-channel amplifier. Only the Channel 1 input is active, and only the Channel 1 Input
Attenuator controls the amp’s output. In this mode, minimum speaker impedance per
channel is 8.
Speaker Impedance and Connections
The minimum speaker impedance is wholly dependent on the operational mode of the
amplifier. It is critical that the minimum impedance not equal less than the
recommended impedance.
11

R-150/R-300/R-500 Reference Series Amplifier
Speaker Connection Procedures
Always switch the power off before connecting speakers.
After removing approximately 10mm (1/4 inch) of insulation from the ends of the speaker
cables, twist the strands tightly and pass the bare ends through the holes in the terminals,
tightening the terminals to secure the wires.
Make certain the wires do not protrude from the terminals and touch the amplifier’s
chassis, or an adjacent terminal.
The R-150/R-300/R-500 is capable of very high output levels. Be certain to use a speaker
system that can accept high input levels. If the input capacity of your speaker system is
less than the amplifier’s rated output, you may protect your speakers by connecting a
fuse between amplifier and speaker, as shown below:
Use the following formula to determine the needed fuse rating:
Po (W) = Speaker’s continuous input capacity (RMS)
R () = Speaker’s nominal impedance
I = Required fuse rating.
For example: if the speaker’s input capacity is 100W, with 8impedance,
The required fuse rating is 3.5A.
12

R-150/R-300/R-500 Reference Series Amplifier
Speaker Cable
Always use the heaviest-duty (lowest gauge) speaker cable available. The terminals can
accommodate very thick speaker cable.
Maintaining Proper Polarity
It is very important to wire your speaker connectors consistently at each end of each
cable, in order to maintain proper polarity. All quality cables are manufactured with
clear markings to identify the different conductors – normally by color-coding,
printed markings, or textured ribbing on the cable’s jacket material. Always make
certain to correctly wire your connections so that tip is connected to tip, and sleeve
to sleeve. Failing to do so will cause your speakers to operate out of phase, resulting
in significantly reduced low-frequency output from your system.
Rack Mounting Your Amplifier
The amplifier expels heat through the rear panel heat sink. When mounting in a portable
equipment rack, maintain adequate ventilation by making certain the front and rear
panels are not obstructed.
13

R-150/R-300/R-500 Reference Series Amplifier
Block Diagram
14

R-150/R-300/R-500 Reference Series Amplifier
Specifications
Rated Output (RMS)
R-150 R-300 R-500
Stereo 8Ω, 1kHz (per channel) 50W 100W 170W
Stereo 4Ω, 1kHz (per channel) 75W 100W 250W
Bridged Mono 8Ω, 1kHz 150W 300W 500W
Frequency Response (± 0.5dB) 20Hz-50kHz
Input Sensitivity 0.775V
Input Impedance 10k (balanced)
T.H.D <0.03%
S/N -105dB
Damping Factor > 100
SlewRate ± 30V/µ sec.
Protection Switch On Delay, Thermal,
DC Fault, PC Limiter
GENERAL
PowerSource AC 110V-240V, 50/60Hz,
Power Consumption
R-150 140W
R-300 210W
R-500 330W
Weight
R-150 7.5kg/16.5lb
R-300 8.2kg/18lb
R-500 13.6kg/29.9lb
Dimensions
R-150/R-300 482(W) x 88(H) x 210(D) mm
19(W) x 3.5(H) x 8.3(D) inches
R-500 482(W) x 132(H) x 280(D) mm
19(W) x 5.2(H) x 11(D) inches
Specifications and design subject to change without notice for improvements.
15

R-150/R-300/R-500 Reference Series Amplifier
Inter-M, Ltd. (Korea) began operations in 1983.
Since then, Inter-M has grown to become one of the largest manufacturers
of professional audio and commercial sound electronics equipment in the world.
Inter-M has gained worldwide recognition for its own branded products,
as well as private label manufacturing of electronics sold under other names (OEM).
The company is no longer just a Korean company, but rather a global company
that is truly international in scope, with factories and offices in Korea and China,
and sales and marketing operations located in Japan, Europe, and the U.S.A.
With more than 850 employees around the globe, Inter-M is well-poised for further growth and
expansion.
INTER-M AMERICAS, INC.
1 EAST BEACON LIGHT LANE, CHESTER, PA, USA 19013-4409
TEL: [phone], FAX: [phone]
Home Page:http://www.inter-m.net, E-mail: [email protected]
INTER-M Corporation
SEOUL OFFICE: 653-5 BANGHAK-DONG, DOBONG-KU, SEOUL, KOREA
TEL: [phone]~8, FAX: [phone]
Home Page:http://www.inter-m.com, E-mail: [email protected]
0704R150300500 PRINTED IN KOREA
16