Cello Master Owners manual

Thank you for choosing the Cello Chorale preamplifier and Ma ster power supply. Your Chorale and Master

have been individually made, from the finest parts and materials available. The Chorale and Master utilize
proprietary circuitry and processes, develo ped by Matthew James, L.L.C., that represent true state of the art in
audio electronics. The Chorale contains the most recent thinking in analog interface circuitry. It offers sonic
performance and reliability, and a great deal of flexibility. It accepts a large number of sources and provides
optimized outputs for recording and listening without compromise. The Chorale and Master are designed to
perform to specification for decades of enjoyment. We hope the Chorale and Master provide you with complete
satisfaction. Please read this information carefully, and care for your Chorale and Master so that they will retain
their value, appearance, and performance.

If you have any questions, contact your authorized Cello representative, or contact Matthew James directly, via

phone [phone]) or email ([e-mail]). It is our wish to assist you in any way possible to
facilitate your enjoyment. These are the private, home office numbers and email address of Matthew James’
Managing Partner. As a result, while you can rest assured that your concerns will be treated with the utmost
urgency, the Managing Partner occasionally travels, sleeps, and listens to music, so he may not always be
immediately available to respond.

Product Concept and Description

In the 17

th

and 18th centuries, Italian master instrument makers developed and virtually perfected what we
regard today as the modern string instruments. The name, Cello, embodies the spirit and concept of our
products. We are dedicated to furthering the art of music reproduction by designing and building equipment of
only the very highest quality , in limited quantities, by hand. Although we are developing and utilizing new

technology, Matthew James is really continuing a very old, traditional approach used by artisans for hundreds of
years. The justification for a great music system is the same as for a great instrument: it makes possible a
musical experience that cannot be duplicated by lesser means.

This philosophy is evidenced completely in the Chorale preamp and Master power supply. They have been

designed to provide sonic quality, consistent performance and reliability. The Chorale preamplifier contains ten
precision audio amplifiers and four power supply regulators to provide the ideal analog interface for each source
component’s signal at the input. It converts the input signal to a high current, precision output for recording or
listening, with an ideal complement of circuits and parts for those tasks.

In the Chorale and Master, low noise, extremely stable parts are used throughout for highest clarity and

maximum resolution. Beyond unsurpassed performance, we demand reliable implementation and longevity from
individual component parts. Following their initial selection, we subject these parts to rigorous performance and
reliability tests before they are assembled into the components. All printed circuit boards use traces that are
drawn by hand, all parts are inserted into the board by hand, and individually soldered to the boards by hand, as
each of these provide tremendously improved reliability and absolute maximization of performance. All internal
signal cabling is hand-made from solid silver, and is shielded and grounded with extraordinary care.

The Chorale preamplifier is built on three levels of circuit boards. The first level is a motherboard that contains

the ground and power supply routing. Extensive ground plane techniques minimize interference from radiated
energies. Large printed circuit paths for DC power reduce detrimental voltage drops caused by resistance and
inductance.

The second level is a second motherboard that contains precision parts and circuit wiring. The active circuitry is

built on individual boards that make up the third level of circuitry and mount on standoffs made from extremely
pure copper flashed with silver through which the signal flows to and from the motherboards. This practice

minimizes any losses and distortions of the signal, while improving contact reliability. Non-magnetic hardware,
used throughout the Chorale, insures that signal flow will not be disrupted by magnetic interference.

The external Master power supply includes a mu-metal shielded 350VA transformer and an initial stage of

regulation which produces + 30VDC. The DC signal is again regulated within the Chorale to provide + 25VDC
individually to the input and output sections through separate regulators. Precision 10 turn trimpots allow exact
calibration of tracking voltages. DC voltages are transported from the Master to the Chorale via substantial,
teflon shielded, copper cables terminated with a heavy duty connector at the Chorale and with substantial
silver/rhodium spades at the Master.

All told, it requires 85 hours of labor to build, assemble and test a completed Chorale and Master.
The chasses of both the preamplifier and power supply are manufactured with heavy aluminum plates on all six

sides. Front, top and side panels are of the traditional clear anodized finish that has been used in Cello products
for the past 20 years. The machining of the internal side of both the top and front pieces provides performance
benefits by reducing the destructive influences of eddy currents, as well as electrostatic and thermodynamic
flows.

Three specially designed feet, utilizing ball bearings of hardened steel and a precision coating, eliminate the

possibility of surface-borne disruptions from affecting the performance of the circuitry. The feet are made from
hardened stainless steel that has been treated with a low -temperature multi-state process of electrocoating based
upon chrome plating technology. The process involves cleaning and removing the matrix on the metals surface
by chemical and mechanical means. The proprietary process causes the metallic elements to permeate the pores
of the metal, actually becoming a part of the metal itself, and insuring a positive lasting bond between the basis
metal and the surface. The precision coating is a deposit of chromium with the addition of spherical diamond
particulates one ten-thousandth of an inch thick, bonded to the stainless steel substrate, with a hardness factor of
98Rc. Between the surfaces of the feet are the 3 stainless steel ball bearings, whose tops and bottoms are the
only points upon which the Chorale and Master (and also the Cello Rhapsody amplifier) rest.

The feet reduce the broadband intermodulation distortion generated when the component is moved however
slightly, and is effective down to a frequency of less than .5Hz. They are located at specific points under the
components to maximize their effectiveness at isolation and allow performance to be unhampered by the
environment. This finish was, until recently, only used in military and aerospace applications, but is now also
used on devices in medical/surgical environments where long life expectancy, extreme wear protection, and low
frictional characteristics are important.

Each of the incremental improvements brought to the Chorale and Master transform familiar recordings into

new discoveries. The unaltered reproduction of the original attack, decay, harmonic structure, temporal
relationships, and dynamics of a performance, reveal the true tonal quality of instruments and voices. The air
and space around the instruments are preserved and the exact location of every performer is discernable. Even
the most complex musical passages are reproduced effortlessly, retaining the most delicate nuances. This level
of performance is only attained by combining advanced technology with a purist’s approach to design and
execution.

In each completed product, superior quality has been assured, first by meticulous planning and design, next by

the choice of the finest materials, then by highly skilled hand construction of each unit, and finally by exhaustive
testing and sonic evaluation.

Music, for thousands of years, has been the inspired expression of human emotion and possibility. Over the

centuries gifted artisans like Amati and Stradivari have enabled composers to more clearly articulate their vision
through the perfection of musical instruments. The dedicated ma ster musician insists on using an instrument
made by a great craftsman. To reproduce music faithfully and exquisitely requires nothing less than the very
best audio equipment. Each product from Matthew James is a blend of proven principles from the past and new
technological understandings. Something new is added only if it proves meaningful in performance.

Only in the last century have musical performances been recorded and for the past 50 years a dedicated group

of people in high end audio have set out to create audio instruments which could flawlessly reproduce those
recordings, with extreme accuracy and reliability over many years. At Matthew James we feel that this can only
be achieved through an inspired fusion of talent including knowledge of musical performance, the mastery of
electronic engineering, and the craftsman’s ability to translate design into a functionally beautiful product.
Working together we seek to produce impeccably crafted electronic instruments of enduring design. Every day
we seek to create new levels of musical enjoyment as the central purpose of our labors.

Unpacking

The packing box for the Chorale preamplifier and Master power supply should arrive in good condition. Please
inspect for damage to the carton, although this is unlikely due to the strength of the carton construction. Open
the packing carefully and save all foam pieces and boxes for re-use in the event the Chorale or Master needs to
be shipped in the future. Should the box become lost, please contact your dealer for replacement carton and
packing material.

Each carton should contain (1) one Cello Chorale preamplifier, (1) one Cello Master power supply, (1) one AC
line cord, (1) DC cable, and (1) one owner’s information / warranty registration sheet.

Installation

Check to make certain that the Master power supply is set to be used at the voltage available in your installation.
There is a small label on the rear panel, at the bottom left, near the AC IN receptacle, which indicates THIS
UNIT IS WIRED FOR, followed by a sticker indicating the voltage at which the unit has been set.

The Chorale preamplifier and Master power supply are connected with a DC cable that is two meters in length.
The Chorale and Master can be situated anywhere, relative to each other, allowed by the two meter length of the
DC cable. The cables are terminated with a heavy duty , 5 pin connector at the Chorale and with substantial
silver/rhodium spades at the Master.

Connect the DC cable to the Chorale by lining up the 5 pins of the connector, labeled DC IN, with the matching
slots on the receptacle terminating the DC cable. Connect the DC cable to the Master using the individually
colored strands of cable to the screw -connected terminal block with the color coded system as labeled on the
back of the Master.