Classe Audio 175-A User manual

CLASSÉ AUDIO
175-A
POWER AMPLIFIER
175-A
OWNER'S MANUAL

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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.

175-A
OWNER'S MANUAL
TABLE OF CONTENTS
UNPACKING & SET-UP................................................................ 4
GENERAL CONNECTIONS.......................................................... 5
CONNECTIONS FOR REGULAR OR BALANCED INPUTS... 7
WARRANTY.................................................................................... 8
SPECIFICATIONS ..........................................................................10
WARRANTY REGISTRATION.....................................................11

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UNPACKING & SET-UP
Your CLASSÉ 175-A 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 has also been
included:
1) Detachable linecord
2) Allen key for top plate
3) Nut driver for CLASSÉ output bolts
Please report any damage or missing parts to your dealer as soon as possible.
Place the 175-A at or near its final set-up position, allowing 8 inches at the rear for tightening the
speaker output connectors.
The power transformer in the 175-A is located at the front-center 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
175-A has only one fuse, the rating of which should be as follows:
LINE VOLTAGE FUSE RATING
100 or 120 V.A.C. 12 AMP FAST BLOW 125 or 250 volts
220 or 240 V.A.C. 8 AMP FAST BLOW 250 volts

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GENERAL CONNECTIONS
A.C. LINE
Making sure the power switch is in the off position; 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 175-A WARRANTY SECTION OF THIS OWNER'S MANUAL.
STEREO
Check the setting on the STEREO/MONO toggle switch, located above the input jacks on the
back of the unit. The lever should be closest to the position marked STEREO.
Input and output connectors are clearly marked on the back of the amplifier. Left/Right
connections are oriented from the front of the unit. Stereo output connections are marked above the
connectors.
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. Tighten the
output bolts with the nut driver supplied, placing the wire or lug between the washer and large chassis
nut. Observe correct phasing of the loudspeaker connections.

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MONO
Firstly, please read through the previous Stereo section for general notes on securing good
connections, and safety tips. If the unit has been previously used in stereo, make sure it is OFF, and
remove all connections. The STEREO/MONO switch is located on the back panel above the input
jacks. The lever should be closest to the position marked MONO.
The MONO input is the left channel input, as marked. The unused right channel input is
automatically disconnected. The output connections are marked BELOW the connectors. (The MONO
positive is the left positive; the MONO negative is the right positive.)
Repeat the above MONO settings and connections on the second 175-A to be used for the other
channel.
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.

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CONNECTIONS FOR REGULAR OR BALANCED INPUTS:
The CLASSÉ 175-A power amplifier is equipped with both regular and balanced inputs. Either
one may be used SEPARATELY BUT NOT SIMULTANEOUSLY. The balanced inputs must be connected to a
preamplifier which has balanced main outputs, and balanced interconnects with "XLR" connectors are
also required. Regardless of the amplifier inputs used, stereo or mono operation is still possible on the
175-A.
REGULAR INPUTS
The amplifier is factory set for REGULAR use. Connect the regular interconnects to the RCA input
jacks on the rear panels of the 175-A, and make sure the toggle switch lever is closest to the position
marked REGULAR. (The BALANCED "XLR" input connectors are automatically disable).
BALANCED INPUTS
A balanced preamplifier and balanced interconnects are also required. For use with balanced
preamplifiers other than Classé, the wiring of the 3-pin XLR connectors must be matched to that of the
Classé 175-A which are wired as follows:
PIN 1: GROUND
PIN 2: POSITIVE (NON-INVERTED) SIGNAL
PIN 3: NEGATIVE (INVERTED) SIGNAL
If the pin configuration of the preamplifier differs from above, the balanced interconnects must be
modified to accommodate the different preamp.
Having confirmed the correct connections, plug the XLR connectors of the balanced
interconnects into the locking XLR connectors on the rear panel of the 175-A. (To remove the
connectors, press the tab above the connector.) Disconnect the 175-A from the A.C. line. Make sure the
toggle switch lever is switched from the REGULAR to the BALANCED position. This activates the
balanced inputs and disables the regular inputs.

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CLASSÉ 175-A LIMITED FACTORY WARRANTY (North America only).
Classé Audio Inc. warrants this amplifier to be free from defects in materials and
workmanship for a period ofFOURYEARS from the date of manufacture, provided that any claim in
virtue of this warranty be made in writing within such period.
Subject to all of the conditions stated herein,ALIMITEDFACTORYLIFETIMEWARRANTYISEXTENDEDONLY
TOTHEORIGINALOWNERWHOPURCHASEDTHEAMPLIFIERINNORTHAMERICAANDWHOCLAIMSUNDERTHISWARRANTYIN
NORTHAMERICA.
IMPORTANT:WARRANTYREGISTRATION,ANDACOPYOFTHE"AUTHORIZEDDEALERBILLOFSALE",MUSTBERECEIVED
ATTHECLASSÉFACTORY(addressbelow)WITHINTWENTY(20)DAYSOFPURCHASE,TOVALIDATETHISWARRANTY.
In the event of failure of this amplifier, resulting from defects in materials and workmanship,
Classé Audio Inc. will repair, recalibrate, or at its discretion, replace the unit providing that all the
conditions contained in this warranty are met.
In order to initiate service of any kind, it is necessary toOBTAINPRIORFACTORYAUTHORIZATION,AND
SHIPTHEUNITPREPAIDTOTHECLASSÉFACTORY. For units coming from outside Canada, contact the factory
for our forwarding address. Units shipped directly to our Canadian address from outside the country
will be stopped at the border, causing extensive delays or return of the unit to the sender.
The warranty shall be void and of no effect in the event of any of the following:
1) Operation not in accordance with this manual;
2) Accident, abuse, tampering, or unauthorized
modification, as determined by Classé Audio Inc.;
3) Removal, defacing, or falsifying the serial number plate;
4) Shipping without the complete factory packaging;
5) Transfer or sale of this amplifier by the original owner;
6) Non-compliance with any of the other conditions hereof.
CLASSÉ AUDIO INC. SHALL NOT BE LIABLE FOR ANY SPECIAL, INCIDENTAL,
OR CONSEQUENTIAL DAMAGES ARISING FROM OR RELATING TO THE SET-UP,
OPERATION, FAILURE, TROUBLESHOOTING, OR REPAIR OF THE AMPLIFIER
AND/OR ANY OTHER EQUIPMENT USED THEREWITH.
THIS WARRANTY, ALL CLAIMS MADE IN VIRTUE HEREOF, AND ALL ISSUES
RELATING TO ANY SUCH CLAIM SHALL BE GOVERNED BY THE LAWS OF THE
PROVINCE OF QUÉBEC.

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CLASSÉ 175-A
CLASS "A" STEREO/MONO POWER AMPLIFIER
FEATURES
AND
SPECIFICATIONS SHEET
175-A FEATURES:
175 watts stereo/700 watts mono, high Class "A" bias current, custom Classé curved heat sinks, rear
external switching for regular or balanced, and stereo or mono operation, thick curved faceplate with
sculpted one piece handles. Available in both Satin Black, and Soft Shadow Silver finishes.
175-A SPECIFICATIONS:
Frequency Response:
Sensitivity:
Input Impedance:
S/N Ratio:
Rated output:
8 Ohms:
4 Ohms:
2 Ohms:
Dimensions: Gross:
Net:
Weight: Gross:
Net:
20 Hz to 20 KHz +/- 0.1dB
1.35 Volt in for rated output
70 KOhms
More than 100 dB
Stereo Mono
175 700 Watts
300 1400 Watts
700 - Watts
25" x 24 3/4" x 14"
19" x 20 3/4" x 8"
90 lbs
78 lbs

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WARRANTY REGISTRATION
You must fill out and return the form below, along with a copy of the authorized dealer bill
of sale, to the factory within twenty (20) days of purchase. This will allow us to provide expedient
service, information regarding updates and new products, and validate the Classé warranty.
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175-A SERIAL NUMBER_____________________PURCHASE DATE_____________________
AUTHORIZED DEALER________________________________________________________
PURCHASER'S NAME_________________________________________________________
STREET ADDRESS____________________________________________________________
CITY________________________________STATE/PROV.____________________________
COUNTRY________________________ZIP/POSTAL CODE__________________________
I BECAME AWARE OF THIS PRODUCT BY:_____________________________________
(DEALER, MAGAZINE, FRIEND, ETC.)
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SEND TO: CLASSÉ AUDIO INC.
Product Registration
5070 François Cusson
Lachine, Quebec, Canada
H8T 1B3