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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 purists 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 master 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.
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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 craftsmans 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 owners 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.
