Product Concept and Description

In the 17th 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 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.

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.

Limited Warranty

Matthew James, L.L.C. warranties all mechanical and electrical parts of the Cello Chorale preamplifier and Master power supply for (5) five years from original date of manufacture.

Dimensions

Chorale: W: 43cm (17.05") x H 14.5cm (5.70") x D 39.4cm (15.51"). Weight: 32lbs.
Master: W: 43cm (17.05") x H 14.5cm (5.70") x D 41.3cm (16.25"). Weight: 36lbs.

Specifications

We do not print specifications because they really do not provide meaningful information.

It is Matthew James' hope that the Chorale preamplifier and Master power supply provide evidence of our desire to develop products that are responsive to the audio requirements of the 21st century marketplace, while maintaining our long-held commitment to the highest levels of sonic performance, stability under actual real-world conditions, and unsurpassed long-term reliability.

 

Matthew James 84 Long Hill Road Middlefield, Connecticut 06455 USA 860 349-5999   Fax 860 349-0579 Email - jimm@matthew-james.net