Classe Audio C-303 User manual

CLASSÉ AUDIO
C-303
REMOTE CONTROL
BALANCED LINE PREAMPLIFIER
C-303
OWNER'S MANUAL

C-303 Issue 1 July ‘98
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CLASSÉ DESIGN PHILOSOPHY
1. REPEATED LISTENING DESIGN SESSIONS:
Fine tuning of sound by exchanging and mixing of parts (transistors, capacitors, wiring, PCB boards
etc.), and adjusting many specific operating voltages within proper engineering ranges, producing an
overall sonic recipe giving the most natural harmonic realism of music typical of instruments in a
live performance.
2. UPGRADABLE SINGLE CIRCUIT DESIGNS:
All Classé products (all preamps and all amps) share exactly the same circuit design philosophy
(excluding moving coil and moving magnet phono circuits). This means all amplifiers and all high
level circuits of the preamps benefit from the same design goals. Similar circuits are then tailored to
different power levels etc. Differences between less expensive models and more expensive models
are parts quality and compliment, power supply extravagance and the amount of filtering etc., as
well as features and packaging.
This means that for years Classé has been constantly sonically fine tuning and technically upgrading
this circuit design and its application, thus reaching a very high level of natural musical enjoyment,
as well as excellent reliability which benefits all models - least expensive, most expensive, preamps
and amplifiers alike.
3. EXTREME LONG LIFE IN REAL WORLD CONDITIONS:
Choosing the best attainable quality parts and materials combined with the advantages of the two
above-mentioned areas provides Classé owners with years of proven trouble free reliability and
musical enjoyment.

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C-303
OWNER'S MANUAL
TABLE OF CONTENTS
UNPACKING & SET-UP..…............................................. 4
A.C. LINE POWER.............................................................. 5
INPUTS................................................................................. 6
OUTPUTS ............................................................................ 9
FRONT PANEL CONTROLS…………………………... 10
REMOTE HANDSET ………………………………….. 12
FEATURES AND SPECIFICATIONS ……...................... 20

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UNPACKING & SET-UP
Your CLASSÉ C-303 preamplifier has been carefully wrapped in heavy gauge plastic, packed in
semi-rigid foam and contained in a special box. To remove the unit, open and spread the top flaps of the
box. By its sides, lift out the entire unit with foam pieces intact. Remove each foam side by pulling
straight out. Remove the plastic wrap and inspect the unit for any concealed damage. Apart from this
owner's manual, please ensure the following has also been included:
1) DETACHABLE LINECORD.
2) ALLEN KEY FOR TOP COVER.
3) REMOTE CONTROL UNIT (Allen key and Batteries: AAA x 2 included).
Please report any damage or missing parts to your dealer promptly.
This preamplifier, being capable of very high gain, must be located in a position free of any
hum-inducing magnetic fields. (This also applies to turntables and interconnect cables.) Positions
adjacent to power amplifiers, A.C line filters, or regulation devices should be avoided. Ideally, a few feet
should separate the preamplifier from the power amplifier. As well, keep low-level interconnect cables
away from the power amp and separate from A.C. linecords.
Heat generated by the preamplifier is negligible. Air space around the unit need not be a
concern.
Check the Serial Number sticker on the back of the unit for the correct operating voltage.
Regardless of voltage, the internal fuse rating should be 2 AMP SLO-BLO.

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A.C. LINE POWER
The Classé C-303 preamplifier has a POWER SWITCH located at the back of the unit directly
to the right of the AC cord receptacle, this permits you to turn on (see SAFETY FEATURE below) or
shut down the unit completely. The Classé C-303 also has a STANDBY BUTTON located on the left
side of the front panel which permits you to partially shut down the unit while keeping warmed up parts
of the circuitry .In fact, while thoroughly musical shortly after turn-on, the preamplifier will exhibit
"sonic growth" during its first 300 hours of use.
For optimum sonic performance, you should consider the use of the optional CLASSÉ REFERENCE
A.C. LINECORD. Consult your dealer regarding this accessory.
SAFETY FEATURE:
The C-303 preamplifier is designed with an auto-muting circuit which engages during the initial
7 seconds count down and is indicated by the flashing GREEN STANDBY LED when the unit is first
powered up, or after an AC power failure if the power switch was on. After the 7 seconds countdown,
the STANDBY LED to the left of the front panel will be GREEN thus showing that the unit is in
STANDBY mode. This feature will prevent any turn-on surges or unstable output from reaching the
power amplifier and possibly the loudspeakers. Similarly, make sure the STANDBY is ON (SHOWING
GREEN) and then turn the POWER SWITCH OFF when removing A.C. line power.
CAUTION:
DISCONNECT AC LINE CABLE WHILE MAKING ALL CONNECTIONS. "FLOATING THE GROUND” OR DEFEATING THE GROUND ON A
3-PRONG LINECORD MAY CREATE A SHOCK HAZARD. CONNECT ALL INTERCONNECT CABLES BETWEEN THE ELECTRONICS
BEFORE CONNECTING THE A.C LINECORDS TO THE WALL OUTLETS. THIS WILL REDUCE THE POTENTIAL SHOCK HAZARD. SEE
ALSO THE WARRANTY SECTION OF THIS OWNER'S MANUAL.

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INPUTS:
The input jacks are clearly marked on the back of the C-303. The following inputs are provided:
REG 1, REG 2, REG 3, REG 4, BAL 1, BAL 2 and TAPE (see fig. 3, page 14).
REGULAR INPUTS REG 1, REG 2, REG 3, and REG4:
These are all high level inputs sharing exactly the same characteristics, and may be interchanged if
so desired. A tape machine should only be connected to the TAPE input. See TAPE IN and TAPE
OUT below. The REG 1 input could also be fitted with an OPTIONAL PHONO BOARD plug in
module installed in the unit, when this is the case, REG 1 input will show LP on the front panel
display. A ground screw is provided adjacent to the REG 1 input jack.
INSTALLATION OF THE PHONO BOARD
1) Disconnect the A.C. line cord from the wall outlet.
2) Remove the top cover with the supplied Allen key.
3) Locate and replace the two mounting screws (see Fig.5, page 17) with the supplied stand-offs.
4) Remove jumpers J5, J6, J13 and J14 (see fig. 5, page 17). Check if extension sockets are in
place on the reverse side of the phono board.
5) Install and secure the phono board using the screws removed previously in step 3 (see fig. 6, page
18), make sure all the connectors are properly aligned.
6) Set MM/MC jumpers J104, 105, 106, 204, 205, 206, to the desired position. All six of these
jumpers are located at the far right of the phono board (see fig. 6, page 18). Please note that for
ALL HIGH OUTPUT MC Cartridges, the jumpers have to be SET AT MM.
7) Replace the top cover.

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REMOVAL OF THE PHONO BOARD
1) Disconnect the line cord from the wall outlet.
2) Remove the top cover with the supplied Allen key.
3) Remove the screws securing the phono board, remove the phono board and the stand-offs,
replace the screws where the stand-offs were removed (see fig. 5, page 17) to secure the main
board.
4) Replace jumpers J5, J6, J13 and J14 (see fig. 5, page 17) on the main board. Jumpers from the
phono board can be used for that purpose.
5) Replace the top cover.
BALANCED INPUT BAL 1 and BAL 2:
The BALANCED INPUT is a true differential high level input, wired as follows:
PIN 1: GROUND
PIN 2: POSITIVE (NON-INVERTED) SIGNAL
PIN 3: NEGATIVE (INVERTED) SIGNAL
It may be used with CD players that have a balanced output, or any other high level
balanced sources.
TAPE IN
The TAPE IN of the C-303 preamplifier should be connected to the LINE OUT or TAPE
OUT of the tape deck. The TAPE input does not appear on the selector switch. It is activated by the
TAPE switch. (See FRONT PANEL CONTROLS: TAPE BUTTON.)

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IR IN (and OUT)
This will permit you to install an outboard infra-red sensor and therefore be able to control
the C-303 remotely from another room where the outboard IR sensor has been installed. These
connections will be found to the left beside the AC power inlet at the back of the unit (see fig.3, page
15).

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OUTPUTS
The Classé C-303 preamplifier has two (2) regular (single-ended) and one (1) balanced
outputs (see fig. 3, page 15). Both single ended and balanced outputs are working at all times, and
may be used separately, or simultaneously.
TAPE OUTPUT
Whatever input is selected by the INPUT SELECTOR will be fed to the TAPE OUTPUT
jacks. This should be connected to the TAPE IN or LINE IN of the tape deck.
REGULAR OUTPUTS
Simply connect your regular interconnects to the RCA output jacks marks REG OUT 1or
REG OUT 2 on the back of the C-303.
BALANCED OUTPUTS
A balanced power amplifier and balanced interconnects are also required. For use with a
balanced power amplifier other than Classé, the wiring of the 3-pin XLR connectors must be wired
as follows:
PIN 1: GROUND
PIN 2: POSITIVE (NON-INVERTED) SIGNAL
PIN 3: NEGATIVE (INVERTED) SIGNAL
If the pin configuration of the power amplifier differs from above, the balanced interconnects
must be modified to accommodate the different power amp.
Having confirmed the correct connections, plug the XLR connectors of the balanced
interconnects into the locking XLR connector on the rear of the C-303 marked BALANCED
OUTPUT. (To remove the connectors, press the tab above the connector.)

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FRONT PANEL CONTROLS
STANDBY
The Classé C-303 also has a STANDBY BUTTON located on the left side of the front panel which
permits you to partially shut down the unit while keeping warmed up parts of the circuitry .
INPUT SELECTOR:
The input selector (see fig.4, page 16) has two buttons for selecting the inputs; (<) and (>).
Pressing the < button.
selects the input to the left of the currently selected input, and pressing the > button selects the input
to the right of the currently selected input. If the > button is pressed when BAL1 is the current input
then the REG1 input will be selected, and if the < button when REG1 is the current input then the
BAL1 input will be selected. The < and > buttons will select from five input connections on the
preamplifier, but not the TAPE, (see TAPE below).
TAPE
In the SOURCE position (TAPE LED OFF), the preamp will process the signal as chosen by
the INPUT SELECTOR. In the TAPE position (TAPE LED ON (RED)), the preamp will process the
TAPE INPUT signal, overriding the INPUT SELECTOR.
VOLUME CONTROL
The VOLUME CONTROL varies the output level of both channels simultaneously. It can be
operated by remote using the hand held control unit (see fig.4, Page 16) or manually
VOLUME CONTROL (CONTINUED)