Classe Audio CAV-75 User manual

CLASSÉ AUDIO
CAV-75
MULTI-CHANNEL
POWER AMPLIFIER
CAV-75
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 (excluding moving
coil and moving magnet phono circuits). This means all amplifiers and all high level circuits of
the preamps are the same. The same circuit is 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 fine tuning and upgrading this circuit and
its application, thus reaching a very high level of understanding and musical achievement 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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CAV-75
OWNER'S MANUAL
TABLE OF CONTENTS
UNPACKING & SET-UP........................................................... 4
GENERAL CONNECTIONS AND OPERATIONS ................ 5
CONNECTIONS AND DIAGRAMS ......................................... 7
PROTECTION CIRCUIT............................................................ 10
SPECIFICATIONS ..................................................................... 12

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UNPACKING & SET-UP
Your Classé CAV-75 multi-channel power amplifier is packed in high density, semi-rigid
foam placed in a special cardboard box. To remove the unit, open and spread all the top flaps of the
box and by its sides, lift out the entire unit and put it on a large flat surface. Take it out of the plastic
bag and inspect the unit for any concealed damage. Apart from this owner's manual, please ensure
the following have also been included:
1) Detachable linecord.
2) Allen key for top plate.
Please report any damage or missing parts to your dealer as soon as possible.
Place the CAV-75 at or near its final set-up position, allowing 8 inches at the rear for
tightening the speaker output connectors. For optimum sonic performance, we recommend the
optional CLASSÉ REFERENCE A.C. LINECORD. Consult your dealer regarding this accessory.
The power transformer in the CAV-75 is located at the front-left of the unit. Ideally, a few
feet should separate this area from components which potentially could pick up hum. These include
preamplifiers, turntables, and interconnect cables. In terms of providing adequate airspace for
cooling, a good rule of thumb is to allow 6 inches above and 3 inches on each side of the unit.
Check the Serial Number sticker on the back of the unit for the correct operating voltage.
The CAV-75 has one line fuse (external), the rating of which should be as follows:
LINE VOLTAGE FUSE RATING
100 or 120 V.A.C. 5 AMP SLOW BLOW 125 or 250 volts
220 or 240 V.A.C. 3 AMP SLOW BLOW 250 volts
INTERNAL RAIL FUSES:
The CAV-75 is designed with each channel protected by one pair of internal fuses for
positive and negative rails (see fig-1 page 7) 3.15 AMP FAST BLOW 125 volts
Mosfet Fuses: 0.75 AMP FAST BLOW 250 volts

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GENERAL CONNECTIONS AND OPERATION:
A.C. LINE
Insert the linecord into the A.C. receptacle on the rear of the unit.
CAUTION: SAFETY INSTRUCTIONS
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.
NORMAL OPERATION:
Input and output connectors for each channel are clearly grouped and marked on the back of
the amplifier. (Units are preset at the factory for NORMAL.) See fig.3a, 3b for typical connections
of the CAV-75.
Use only high quality interconnect and loudspeaker cables, and make all connections tight. If
the input plugs are loose, remove them and pinch down the ground leaves slightly with pliers.
Observe correct phasing of the loudspeaker connections, and tighten.

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BRIDGED OPERATION:
The six (6) channels of the CAV-75 are divided into three (3) groups. These groups can be
operated and configured independently _ Channel-1 with Channel-2, Channel-3 with Channel-4, and
Channel-5 with Channel-6. When in bridged mode, the inputs of CH-1, CH-3 and CH-5 are used
respectively (as marked above the jacks). The unused inputs of CH-2, CH-4 and CH-6 are
automatically disconnected when configured in bridged mode. The following steps should be
performed to switch between NORMAL and BRIDGED modes.
1) Turn OFF the unit and remove all connections, including the AC linecord.
2) Remove top cover with the Allen key supplied.
3) Locate the input board(s) of channels to be switched. (see fig.1 page 7)
4) Locate and set jumpers to the desired operation mode. (see fig.2a, 2b page 8)
5) Replace and secure the top cover.
6) Reconnect all cables. Make sure the input and output connections are according to the
operating mode. (see fig.3a&3b page 9)
Please read through the previous normal section for general notes on securing good connections, and
safety tips.
CAUTION: Please remember that the negative output connection of a bridged amplifier is NOT a
ground. Do not use a "common ground" or switchbox set-up. Do not use with electronic crossovers
which have a common ground.
REMOTE CONTROL: (optional)
With a simple connection from the receiver box to the remote jack at the back of the
amplifier, (see Fig.2 page 8) the power amplifier can be turned ON/OFF from a distance (or from
another room).

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PROTECTION CIRCUIT
The Classé CAV-75 is equipped with rail fuses to protect the output drivers (see fig.1, page 7)
and mosfet fuses to protect the mosfets, which are used as pre-drivers for the output stage of the
amplifier. In the event that a short circuit or other problems would occur at the output of the
amplifier, either or both of these fuses may blow in an attempt to protect the amplifier.
To return the unit to proper operation, TURN THE UNIT OFF. Make sure that the situation
that has triggered the protection circuit has been corrected. Failing to correct the situation prior to
re-starting the unit can result in damaging vital components in the unit.
Replace mosfet or rail fuses (see page 4 for fuse values) that are damaged with exactly the
same type and value. Spare fuses for the mosfet and the output section are supplied with the unit
and included in the instruction booklet package. After a careful inspection of all connections and
components in the system, re-start the unit.If unit still goes into protection mode, contact your
local dealer or Customer Service at the Classé Audio factory---(514) 636 63 85.