Matthew James cello encore User manual

Cello enCore amplifier
Owners manual

Thank you for choosing the
CELLO ENCORE AMPLIFIER
Your Encore has been individually made by hand, from the nest parts and mate-
rials available. The Encore utilizes proprietary circuitry and processes, developed
by Matthew James’ Showroom, L.L.C., that represent true state of the art in audio
electronics. The Encore is designed to perform to specication for decades of
enjoyment. We hope the Encore provides you with complete satisfaction. Please
read this information carefully, and care for your Encore so that it will retain its
value, appearance, and performance.
If you have any questions, contact your authorized Cello representative, or con-
tact Matthew James’ Showroom 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 oce numbers and email
address of Matthew James’ Managing Partner. As a result, you can rest assured
that your concerns will be treated with the utmost urgency.

WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK,
DO NOT EXPOSE THIS COMPONENT
TO RAIN OR MOISTURE.
RISK OF ELECTRICAL SHOCK
DO NOT OPEN
CAUTION:
TO REDUCE THE RISK OF ELECTRICAL SHOCK,
DO NOT REMOVE COVER.
NO USER-SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED PERSONNEL.
Marking by the “CE” symbol (shown left) indicates compliance of this
device with the EMC (Electromagnetic Compatibility) and LVD (Low Voltage
Directive) standards of the European Community.
Please read all instructions and precautions carefully and completely
before operating your Cello Encore power amplier.
1ALWAYS disconnect the entire system from the AC mains before connecting or disconnecting
any cables, or when cleaning any component.
2AC extension cords are not recommended for use with this product.
3NEVER use ammable or combustible chemicals for cleaning audio components.
4NEVER operate this product with any covers removed.
5NEVER wet the inside of this product with any liquid, or pour/spill liquids directly onto this unit.
6NEVER block airow through ventilation slots.
7NEVER bypass any fuse or replace any fuse with a value or type other than those specied.
8NEVER attempt to repair this product. If a problem occurs, contact your Cello retailer.
9NEVER expose this product to extremely high or low temperatures.
10 ALWAYS unplug sensitive electronic equipment during lightning storms or if the unit
will not be used for a prolonged period.

Product Concept and Description
Back in 1986, Cello introduced the Performance Amplier which was designed to provide
the most natural sound and widest dynamic range from recordings. The new Cello
Encore amplier is the rst amplier to really sound like a Performance Amplier because
it uses the driver board from the original Performance, updated to modern parts and
assembled using traditional techniques.
Rated at 125w/ch @8ohms the stereo Cello Encore amplier comes in two chasses with
the amplier channels residing separately from the Cello Master power supply in exactly
the same way that the Cello Chorale preamplier is powered by the Cello Master.
The Cello Encore amplier from Matthew James incorporates a number of engineering
advances which allow high performance in a compact and ecient design, providing a
practical and appealing product for inclusion in music systems of the highest quality. The
circuitry is exceptionally stable and can be used with speakers which present loads as
low as 1ohm.
The Encore is designed to have the lowest possible levels of distortion while under actual
use, as opposed to simply measuring well on a test bench. The circuitry is designed
to perform well under the complex resistive, reactive and regenerative loading which
loudspeakers present to an amplier. The design approach has been to place importance
on the requirements of actual music reproduction. Many ampliers utilize some form of
soft-clip circuitry to deal with overload. The problem is that many of these approaches
introduce additional forms of distortion before the actual overload threshold is reached.
Furthermore, most designs to control overload are not comprehensive in dealing with
all of the situations that negatively aect an amplier’s ability to remain stable under
demanding situations. The Encore has been designed to control all forms of overload
under all conditions.
Considerable eort has been made to reduce low frequency errors, because most of
the energy in music and lm sound reproduction is present in this part of the frequency
spectrum. It is crucial to maintain low intermodulation distortion of low level, high
frequency information in the presence of large low- and mid-frequency signals under
complex loading. The Encore is designed to have the lowest distortion at small signal
levels and to gradually increase with signal level. While this results in slightly higher total
harmonic distortion (THD) measurements at full power levels, it conversely allows for the
lowest possible distortion under actual listening conditions. Again, the requirements for
accurate music reproduction have taken precedence in all design decisions.
The input stage of the Encore amplier remains under control under any overload
condition. The design tactics were chosen because they provide wide dynamic range
and provide a greater measure of resistance to overload than other possible choices.

The output stage of the stereo Encore employs one pair of 250 watt, metal case, bipolar
output devices per channel. The number and type of devices were chosen because they
remain stable with a less complex circuit, requiring less negative feedback, and are easier
to match to each other than other possible choices for this stage. The choice of devices,
the location of devices on the heat sinks, and the heat sinks themselves were carefully
considered to minimize the temperature variations among the output devices. The
power devices are mounted with all metal hardware, compression washers and special
graphite and metal composite gaskets to insure maximum thermal conductivity and
full utilization of the output devices. Once again, consistent performance, stability and
reliability under normal conditions of actual use were the driving factors in the design.
All electrical connections for signal ow within the Encore are accomplished via at,
very pure silver and copper cables insulated with Kapton. The chassis is manufactured
with heavy aluminum plates on all six sides. (3) Three specially designed feet, utilizing
ball bearings of hardened steel with a proprietary coating, eliminate the possibility of
surface-borne disruptions from aecting the performance of the circuitry.
Unpacking
The packing box for the Encore amplier 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 Encore needs to be shipped in the future. Should the box become lost,
please contact your dealer for replacement carton and packing material.
Each Encore carton should contain:
(1) one Cello Encore amplier,
(1) one DC cable with
(5) ve color coded conductors,
(1) one owner’s information sheet.
An important part of the Cello philosophy is found in the physical separation of the
power supply from the active circuitry of either the preamplier or the amplier. The
external Master power supply includes a mu-metal shielded transformer and power
supply regulation. DC voltages are transported from the Master to the Encore via teon
shielded, copper cables terminated with substantial copper/rhodium spades.
Encore inside chasis

Each Master carton should contain
(1) one Cello Master power supply
(1) one AC cable.
Installation
Be certain that the Encore amplier and Master power supply are installed so that they
have proper ventilation. The ambient temperature should not exceed 122 degrees F (50
degrees C).
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 Encore amplier and Master power supply are connected with a DC cable that is
two meters in length. The Encore 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
substantial copper/rhodium spades at both the Encore and the Master.
Connect the DC cable to the Encore and 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 both the Encore and the Master.
Connect inputs 1 & 2 of the Encore via XLR terminated interconnect cables, and to the
line outputs of your preamplier or other source component.
Connect outputs 1 & 2 of the Encore via speaker cables and to the corresponding
terminals of your speakers.
Master inside chasis

Connect the AC line cord from the IEC connector on the rear of the amplier to the power
outlet in your home.
Push the rear panel power button to turn the unit on. Your Encore and Master should now
be functioning and the LEDs on the front panels should be illuminated and red in color.
Service
If you believe your Cello Encore amplier is not functioning properly, please contact your
dealer / distributor. If you need to return your component, you will be given a Return
Authorization Number (RA#). This number must appear on the outside of the shipping
carton. Returns without RA#s will not be accepted. Returns received in original packing
material will be returned in original packing. Returns received in non-original packing
material will be returned in new packing at the owner’s expense. If you need new packing
material to return your Encore or Master, please contact your dealer / distributor.
Maintenance
The nish of the Cello Encore amplier is machined aluminum that has been brushed (top,
sides, face), and powder coat painted (rear and bottom). Ammonia based glass cleaner,
or a (3 to 1) three to one mixture of Grain Alcohol and distilled water, applied with a soft
white, lint free cloth, works well to remove ngerprints and other dirt. Take care when
cleaning the rear panel as excessive rubbing may remove the silk-screened lettering. Be
sure that the amplier is turned o and disconnected from the AC line before cleaning and
always try to keep excess cleaning uid from getting inside the amplier.
Limited Warranty
Matthew James’Showroom, L.L.C. warranties all mechanical and electrical parts of the
Cello Encore amplier and Master power supply for (5) ve years from original date of
manufacture. Labor expenses associated with the service of the Encore amplier and
Master power supply are the responsibility of the dealer or distributor, if applicable, except
as follows:

Any defect in the Encore amplier and Master power supply within the rst (2) two years
from the original date of manufacture shall be repaired by the dealer / distributor with
labor expenses paid by Matthew James’ Showroom, L.L.C. according to factory rates for
a given repair. At Matthew James’Showroom’s discretion, or if the dealer / distributor
is unable to perform the repair, the unit may be returned to the factory for service
using agreed upon airfreight. After repair the unit will be returned by the same carrier
or equivalent. During years (3-5) three through ve, if the dealer / distributor is unable
to perform the repair, Matthew James’ Showroom will pay the return airfreight from
the factory by agreed upon carrier, provided the unit was shipped to the factory with
airfreight prepaid.
Matthew James’Showroom will not pay freight costs if the unit is returned without a
Return Authorization Number (RA#).
Matthew James’Showroom will not pay the freight if the unit is found to be in working
order.
There is no reason to register your warranty. It is done so automatically by the factory.
We respect owner’s privacy and don’t try to gather information without the owner’s
knowledge and consent. Warranty is automatically transferred to a subsequent owner
who may wish to verify date of manufacture and remaining warranty period. If you
want to register to receive product information, or nd out more about Matthew James’
Showroom or Cello products, we invite you to visit our web page at either www.matthew-
james.net or www.cello-audio.net.
Warranty of Repair Work Performed
Any specic repairs or modications eected by Matthew James’ Showroom, or authorized
service facility, shall be guaranteed for 100% parts and labor for the remainder of the
original warranty period for this particular unit, or (1) one year, whatever is longer.
Tampering, Abuse or Misuse
Any unauthorized modications, repairs or tampering, and/or any indication of owner
abuse, negligence or improper usage, as determined by Matthew James, L.L.C., will result
in the voiding of the warranty. There are no user serviceable parts inside.
Dimensions:
Encore: 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.

Specications
Power Output:
Encore stereo amplier: 125 w/ch @ 8ohms
Encore mono amplier: 500 w/ch @8ohms
IMD SMPTE (60Hz and 7kHz): <0.3%
THD (20-20kHz): <0.3%
Frequency Response: -.3dB @20kHz
Signal to Noise: -100dB @1kHz
Gain:
28.5dB single ended
34.5dB balanced
Input Sensitivity:
752mV single ended
376mV+/- balanced
Input Impedance: 330kohms non-inverting / 5kohms inverting
It is Matthew James’ Showroom’s hope that the Encore amplier 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.

Encore Mono Amplier
The Encore amplier can be bridged, resulting in a mono amplier with 4 times
the power capabilities of the stereo version. The Encore mono is a no compromise
design, combining musical clarity, sonic renement and power.
The Encore mono achieves ultra-low distortion into any load, exceptional bass
control, natural tonal quality and the power to drive any speaker to its maximum
impact and dynamic potential. It is the ultimate power amplier ever produced
under the Cello brand.
Bridging is accomplished internally for both maximum performance and so that the
user is presented with a very simple connection.
Rear Panels of the Encore mono ampliers and Master power supplies

The Cello Integrated Amplier
A stereo Encore amplier and a Chorale preamplier can be powered by a single
Master power supply providing state of the art performance at a price seldom
associated with such a performance level.
Rear Panels of the Chorale preamplier,
Encore stereo amplier and Master power supply

Cello products are designed and built by hand in
Connecticut, USA by
Matthew James’Showroom, L.L.C.
84 Long Hill Road
Middleeld, CT 06455
Phone [phone]
Email [e-mail]