Classe Audio C-151, C-151 Europe Owners manual

CLASSÉ AUDIO

C-151

REMOTE CONTROL

BALANCED PREAMPLIFIER

C-151

OWNER'S MANUAL

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.

C-151

OWNER'S MANUAL

TABLE OF CONTENTS

UNPACKING & SET-UP......................................................... 4

A.C. LINE POWER................................................................... 5

INPUTS...................................................................................... 6

JUMPER SETTING DIAGRAMS (MC/MM,) ...................... 10

OUTPUTS ................................................................................. 12

FRONT PANEL CONTROLS.................................................. 13

FEATURES AND SPECIFICATIONS ................................... 16

3

UNPACKING & SET-UP

Your CLASSÉ C-151 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).

4) RESISTOR KIT FOR MOVING COIL GAIN ADJUSTMENT. (with optional phono only)
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 1 AMP SLO-BLO.

4

A.C. LINE POWER

The Classé C-151 preamplifier has no power switch. Its low power consumption and improved
sonics from always being ON led to the omission of an ON/OFF switch. 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-151 preamplifier is designed with an auto-muting circuit which engages and is indicated
by a FLASHING GREEN LED when the unit is first connected, or after an AC power failure. After 15
seconds the STEADY GREEN LED signals that the unit is in STANDBY mode (Note: MUTE is ON
during 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 MUTE is ON (STEADY GREEN)
again 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.

5

INPUTS:

The input jacks are clearly marked on the back of the C-151. The following inputs are
provided: PHONO/AUX, VIDEO, CD, TUNER, BALANCED, and TAPE.
PHONO/AUX
The C-151 preamplifier can be configured as a PHONO unit by installing the optional
internal phono board onto the main board. The PHONO and AUX inputs share the same pair of RCA
input jacks. The GND screw is located next to PHONO/AUX input jacks. The following steps
should be performed to remove or install the phono board.

1) Make sure MUTE is ON (Steady GREEN)

2) Disconnect A.C. linecord from the wall outlet.

3) Remove the top cover with the Allen key supplied.
PHONO CONFIGURATON: (installation of phono board)

4) Locate and replace mounting screws 1, 2, 3 with the stand-offs supplied.

5) Remove jumpers J1, J2 (see fig.1, Page 9)

6) Install and secure the phono board using screws in step 4, make sure all connectors are
properly aligned. Set MC/MM jumpers if required (see fig-2a, 2b page 10). Replace the top
cover.
AUX CONFIGURATION: (removal of phono board)

7) Reverse steps 4, 5, and 6, make sure jumpers J1 and J2 are reinstalled for AUX
operation. (see fig.1a, page 9)

6