Conrad-johnson design Motif MS2001 - User Manual

Congratulations on your purchase of the Motif MS2001 MOSFET ampli-
fier. You have acquired one of the finest pieces of musical reproduction
equipment available today. Motif is the result of over a decade of
research by conrad-johnson design into the application of solid-state
devices to the reproduction of recorded music. Both design and materi-
als have been carefully selected to yield years of unvarying excellence.
Each unit has been painstakingly hand-assembled and exhaustively
tested.
Please take a few minutes to read this manual so that you will better
understand the features and capabilities of your MS2001.
Motif MS2001 Owner’s Manual 1

Summary

LIMITED WARRANTY FOR THE MOTIF MS2001

Warranty Coverage

Details the manufacturer's warranty period and coverage for material and workmanship defects.

Warranty Repair Conditions

Outlines conditions for warranty repairs, including no misuse, proof of purchase, factory service, and original packaging.

Liability and Disclaimers

States limitations on liability, disclaims other warranties, and addresses consequential damages.

Warranty Service Contact

Informs users about specific legal rights and provides contact information for warranty service inquiries.

REGISTERING THE WARRANTY

Warranty Registration Process

Instructs users to return a card to the factory within 30 days to register their warranty for important updates.

INSTALLATION

Ventilation and Placement Requirements

Details essential ventilation, placement, and clearance requirements for the amplifier to manage heat dissipation effectively.

Rack Mounting Considerations

Explains that the unit fits standard 19" racks and emphasizes maintaining adequate clearance above for ventilation.

Hum Minimization and Voltage Operation

Advises on minimizing hum by proper cable routing and specifies the required AC line voltage for operation.

Connection Guide

Provides instructions for connecting input sources via RCA and outputting to loudspeakers using binding posts.

GETTING THE MOST FROM YOUR MOTIF MS2001

System Setup and Component Matching

Stresses the importance of proper system setup and careful component matching for optimal performance.

Understanding Absolute Phase

Explains the concept of absolute phase in audio reproduction, defining phase correct and phase inverting components.

Verifying System Phase Correctness

Guides users on how to achieve correct absolute phase in their system and how to verify it by listening.

Front Panel Indicator Lights

Describes the function of the front panel LED indicators, including power status and maximum power output.

Importance of Audio Cables

Highlights the critical role of interconnect and speaker wires in achieving optimal system performance and suggests consulting dealers.

SPECIFICATIONS

Technical Performance Data

Lists key technical specifications including power output, sensitivity, frequency response, impedance, dimensions, and weight.

Fuse Specifications and Replacement

Details the types and ratings of fuses used in the MS2001 and provides critical warnings against using incorrect replacements.

SERVICE

Service and Shipping Procedures

Provides instructions for packing and shipping the unit for service, including enclosing a problem description and proof of purchase.

Overview

1. Function Description
2. Important Technical Specifications
3. Usage Features
4. Maintenance Features

The Motif MS2001 is a high-fidelity MOSFET amplifier designed for musical reproduction. It is the culmination of over a decade of research by conrad-johnson design into the application of solid-state devices for audio. Each unit is meticulously hand-assembled and exhaustively tested to ensure unvarying excellence.

Function Description:

The Motif MS2001 serves as a stereo power amplifier, designed to amplify audio signals from a preamplifier and drive loudspeakers. It aims to provide an unparalleled level of sophistication and refinement in music reproduction. The amplifier is designed to be phase correct (non-inverting), which is crucial for accurate sound reproduction. It features front panel LED indicators to show its operational status and maximum voltage swing.

Important Technical Specifications:

• Power Output: 200 watts per channel RMS into 8 ohms, with both channels driven, from 20Hz to 20KHz, at no more than 1% total harmonic distortion or intermodulation distortion.
• Sensitivity: 2.1V to rated power.
• Phase: Phase correct (non-inverting).
• Frequency Response: 20Hz to 20KHz +0, -.25 dB.
• Hum and Noise: 100 dB below full power output.
• Input Impedance: 100K ohms.
• Dimensions: 18.5 inches (Depth) x 19 inches (Width) x 7 inches (Height).
• Weight: 63 lbs.
• AC Line Voltage: Designed for operation on 108 to 125 volts AC. Optionally available wired for 100 volt, 220V, or 240 volt, 50/60 Hz current.

Usage Features:

• Installation and Ventilation: Due to considerable heat dissipation, proper ventilation is essential. The unit should be mounted horizontally on a flat, hard surface, ensuring heat sinks are unobstructed. A minimum of six inches of clearance above the unit and two inches on the sides is recommended. Cabinets or shelves should be open at both front and back; cooling fans are necessary for more restricted installations. The front panel fits a standard 19" equipment rack and is designed to support the unit's weight for rack mounting, with about six inches of open space above the front of the rack for ventilation.
• Hum Pickup Minimization: To minimize hum, the amplifier should be kept well away from the preamplifier and turntable, and power cords should be routed away from input cables.
• Input Connections: Preamplifiers connect to the MS2001 amplifier via RCA type connections located on the amplifier heat sinks.
• Output Connections: Five-way binding posts are provided for loudspeaker connections. These posts are spaced to accept standard "double banana" plugs and can also accommodate spade lugs, bare wire, or pin connectors.
• Relative Phase Connection: It is crucial to connect the two channels in correct "relative phase" so that speaker diaphragms move synchronously. This is typically achieved by connecting the wire from the red (+) amplifier terminal to the red or "+" coded terminal on each speaker. Correct relative phase can be audibly verified: a solo vocalist's voice should be clearly focused between the speakers when in phase, and diffuse when out of phase. Relative phase can be corrected by switching the "+" and "-" leads at one speaker only.
• Absolute Phase: The MS2001 itself is phase correct. Users are advised to ensure their entire stereo system maintains correct absolute phase. If the system has an odd number of phase inversions, an additional inversion can be introduced by reversing the positive and negative connections on either the cartridge or speakers (on both channels). Correct absolute phase results in noticeably cleaner and more sharply defined transients, especially on plucked string sounds.
• Front Panel Indicators:
  • An LED next to the power switch illuminates when the turn-on delay relay activates, indicating the amplifier is ready for use.
  • Two "maximum power" LEDs light up when the amplifier reaches its maximum voltage swing. These lights indicate that the amplifier is handling most transients, and should not remain continually lit during normal operation.
• Importance of Wires: The choice of interconnect and speaker wires significantly impacts system performance. Users are advised to consult their Motif dealer for recommendations tailored to their specific system.

Maintenance Features:

• Warranty: A three-year limited warranty covers defects in material and workmanship from the date of original purchase. The warranty requires the unit not to have been altered or damaged by misuse, abuse, negligence, accident, or improper operation. Proof of purchase is required for service. All repairs must be undertaken by the factory or a designated service center. Units for warranty repair must be shipped in the factory packing carton, freight and insurance prepaid by the owner, and will be returned prepaid. Normal wear and maintenance are not covered.
• Warranty Registration: Users are encouraged to return the enclosed warranty card within 30 days of purchase to register the warranty. This ensures they receive information about design alterations and new products.
• Fuses: The MS2001 contains 5 user-replaceable fuses.
  • Four power supply fuses (type 3AG 5 amp fast-blo) are located above the output jacks.
  • One AC line fuse (type 3AG 10 amp slo-blo) is located below the input jacks (7 amp slo-blow for 220V or 240V amplifiers).
  • Crucially, fuses must NEVER be replaced with a value or type different from that originally supplied by the factory. Repeated fuse blowing indicates a problem, and users should contact their dealer or the conrad-johnson service department.
• Service: In case of service needs, the unit should be repacked in its original packing material and shipped via United Parcel Service (UPS) to the conrad-johnson design, inc. Service Department at 2733 Merrilee Drive, Fairfax, VA 22031. A detailed note explaining the problem, including any intermittent issues, should be enclosed. If original packing material is unavailable, replacements can be purchased from conrad-johnson design. A copy of the purchase receipt is required for warranty service.
• Customer Support: For any questions regarding installation or function, customers can contact Customer Service at (703) 698-8581.

Conrad-johnson design Motif MS2001 Specifications