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

LIMITED WARRANTY FOR THE MOTIF MS2001
1. conrad-johnson design, inc. warrants to the original owner that the
Motif MS2001 will be free from defects in material and workmanship for
a period of three years from the date of original purchase.
2. During the warranty period, conrad-johnson will repair defective
units without charge for labor or parts subject to the following conditions:
a)The unit must not have been altered or damaged through
misuse, abuse, negligence, accident or improper operation.
b)The purchaser must provide evidence of purchase at the time
service is requested.
c) All repairs must be undertaken at the factory or other service
center designated by conrad-johnson design, inc. Units submitted
for warranty repairs must be shipped in the factory packing carton
to conrad-johnson design or its designated service center, freight
and insurance prepaid by the owner, and will be returned to the
owner, freight and insurance prepaid by conrad-johnson design.
Replacement cartons are available from the factory for a nominal
charge.
d) Normal wear and maintenance are not covered by this warranty.
3. Where permitted by law, conrad-johnson design’s liability shall be
limited to that set forth in this warranty. No other warranty of any kind,
expressed or implied, is made by conrad-johnson design, inc., and all
implied warranties, including merchantability and fitness for a particular
"purpose", which exceed the obligations and time limits set forth herein
are hereby disclaimed. conrad-johnson design, inc. shall not be liable
for incidental or consequential damages. Some states do not allow the
exclusion or limitations on how long an implied warranty lasts, so the
above limitation or exclusion may not apply to you.
4. This warranty gives you specific legal rights, and you may also have
other rights which vary from state to state. Questions about warranty
service should be addressed to:
Service Department
conrad-johnson design, inc.
2733 Merrilee Drive
Fairfax, VA 22031
Motif MS2001 Owner’s Manual 2

REGISTERING THE WARRANTY
Please return the enclosed card to the factory within 30 days of pur-
chase to register the warranty. Proper registration of the warranty is
important! It will enable us to inform you of any alterations in the design
of a given model and of any new products we offer which are likely to be
of interest to you.
Motif MS2001 Owner’s Manual 3

INSTALLATION
Because the MS2001 amplifier dissipates considerable heat it is essen-
tial that proper attention be paid to ventilation. The unit should be
mounted horizontally on a flat hard surface so that the heat sinks are
unobstructed. At least six inches of clearance should be provided above
the unit, and at least two inches on the sides. The cabinet or shelf should
be open at both front and back. For more restricted installations, cooling
fans are essential.
The front panel of the MS2001 will fit in a standard 19" equipment rack
and is designed to carry the weight of the unit so that it may be rack
mounted. Again, it is important that adequate clearance be provided
above so that ventilation is not impeded. About six inches of the front of
the rack should be left open above the unit.
To minimize hum pickup, keep the unit well away from the preamplifier
and turntable and route power cords away from input cables.
THEMS2001ISTOBE OPERATED ONLYON AC LINEVOLTAGE OF
108 TO 125 VOLTS.
The MS2001 is optionally available wired for 100 volt, 220V or 240 volt,
50/60 Hz current.
CONNECTION
INPUT: Connect the preamplifier to your MS2001 amplifier at the RCA
type connections located on the amplifier heat sinks.
OUTPUT: Five way binding posts are provided for connection of your
loudspeakers, with correct spacing to accept a standard "double ba-
nana" plug. They will also accept spade lugs, bare wire, or pin connec-
tors.
The two channels should be connected in correct "relative phase".This
means that when the same signal is applied to both channels, the right
and left channels speaker diaphragms should move synchronously - in
and out together. Terminals on the speakers are usually coded - one
Motif MS2001 Owner’s Manual 4

designated "C", "earth", "ground", "-" or black, the other designated "+"
or red.
"In phase" connection of the speakers can normally be achieved by
takingcaretoconnectthewirefromthered(+)amplifierterminalmarked
on each channel to the red or "+" coded terminal on each speaker.
Correct relative phase connection of the speakers can be readily ascer-
tained by ear. Play a recording of a solo vocalist. With the speakers in
phase the voice should be clearly focused between the two speakers.
Withthespeakers connected out of phase, the voice will be diffuse, with
no identifiable source. Relative phase may be reversed by switching the
"+" and "-" leads at one speaker only.
Motif MS2001 Owner’s Manual 5

GETTING THE MOST FROM YOUR MOTIF
MS2001
The Motif MS2001 offers an unparalleled level of sophistication and
refinement in music reproduction, but it cannot transform an inferior
stereo system. Only the very best loudspeaker systems will be capable
of fully revealing the capabilities of this precision instrument. On the
other hand, the MS2001 is ruthlessly revealing. For example, it can
render unacceptable faults in the phono system which may be just
discernable with an amplifier of lower resolution.
Proper set-up is important in any high-fidelity system, but with state-of-
the-art components it is essential. Before attempting to evaluate the
MS2001, be sure that your phono system has been set up carefully
according to manufacturer recommendations. Adjustment of the car-
tridgeverticaltracking anglecanbe especially criticalwithmodern stylus
configurations.
Given a system of high quality components, there remain a number of
important details which must be attended to.
ABSOLUTE PHASE
Musical notes are heard through the ear’s response to waves of alter-
nating rise and fall of air pressure. Musical transients are exclusively
positive: that is, the initial effect is a rise in pressure. The ear is capable
of distinguishing these positive transients from the musically unnatural
alternative of a negative transient (an initial fall in air pressure). In your
stereo system, these transients are created by your loudspeakers. If the
speakers respond to musical transients by first moving out, they are
creating a rise in pressure, and the system is said to be "phase correct".
If they respond by moving in, they create a fall in pressure and the
system is said to be "phase inverting". Each component in the stereo
system is either phase correct or phase inverting (including the cartridge
and speakers - these are normally phase correct). It is of no conse-
quence if an individual component is phase inverting, as long as the
system as a whole is phase correct. This will be the case as long as the
number of phase inversions is even (or zero).
Motif MS2001 Owner’s Manual 6

THEMS2001 ISPHASE CORRECT. If your system has an odd number
of inversions, then you must add one phase inversion. This is conven-
iently done by reversing the positive and negative connections on either
your cartridge or your speakers (be sure to reverse both channels).
If you are not sure about the phase of every component in your system,
you can establish correct absolute phase by careful listening. When the
system is in correct phase, transients will be noticeably cleaner and
moresharply defined.Theeffectisespeciallyapparenton pluckedstring
sounds. A final warning - not all records are phase correct (including
some "audiophile" recordings), so listen to several before concluding
your investigation of absolute phase.
FRONT PANEL INDICATORS
The MS2001 uses three front panel LED indicators. The LED next to the
power switch turns on when the turn-on delay relay turns on, indicating
that the amplifier is ready to use. The two LEDs marked "maximum
power" will light when the amplifier reaches its maximum voltage swing.
This will generally be inaudible as the MS2001 has sufficient headroom
to handle most transients. The amplifier should not be operated at such
a level as to keep these LEDs continually lit.
THE IMPORTANCE OF WIRES
Interconnect and speaker wires are an important element in your stereo
system. Interconnects are available which will permit a reference quality
system to blossom and fulfill its promise of musical reality. Others will
strangle the system to the point where it becomes no better than
average. To complicate matters, our experience suggests that the
choice of interconnects will be system dependent-those that are ranked
first on a given system may be a poor choice for a different system.
Consult your Motif dealer for recommendations for your specific system.
QUESTIONS: If you have any questions about the installation or func-
tion of your MS2001 do not hesitate to call Customer Service at (703)
698-8581.
Motif MS2001 Owner’s Manual 7

SPECIFICATIONS:
Power: 200 watts per channel RMS both channels driven into 8 ohms
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: 18.5D x 19W x 7H inches.
Weight: 63 lbs.
Fuses: There are 5 user replaceable fuses in the MS2001. The four
fuses above the output jacks are power supply fuses, type 3AG 5 amp
fast-blo. The fuse below the input jacks is an ac line fuse, type 3AG 10
amp slo-blo (7 amp slo-blow for 220V or 240V amplifiers). NEVER
REPLACE A FUSE WITH A VALUE OR TYPE DIFFERENT FROM
THAT ORIGINALLY SUPPLIED BY THE FACTORY. In the event of a
fuse blowing repeatedly, contact your dealer or the conrad-johnson
service department.
Motif MS2001 Owner’s Manual 8

SERVICE
Intheevent yourMotifMS2001 stereo amplifierrequiresservice, repack
it with the original packing material and ship via United Parcel Service
(UPS) to: conrad-johnson design, inc.
Service Department
2733 Merrilee Drive
Fairfax, VA 22031
Be sure to enclose a note explaining the problem you are having in as
much detail as possible. If the problem is intermittent, please indicate. If
you do not have the original packing material, replacements are avail-
ablefromconrad-johnsondesignatanominalcharge.Iftheunitisunder
warranty, be sure to enclose a copy of your receipt as proof of purchase.
Motif MS2001 Owner’s Manual 9