aPA7.5 Mono - Audio Amplifier Cyrus Audio - Free user manual and instructions

Product Type	Mono Power Amplifier
Brand	Cyrus Audio
Model	aPA7.5 Mono
Output Power (8 Ohm)	150W RMS
Output Power (4 Ohm)	240W RMS
Frequency Response	0.5Hz - 130kHz (-3dB)
Signal-to-Noise Ratio	114dBA (ref. 150W / 8 Ohm)
Total Harmonic Distortion (THD+N)	< 0.004% (1kHz, 8 Ohm)
Input Sensitivity (RCA)	381mV (50W), 660mV (150W)
Input Sensitivity (Balanced)	775mV (50W), 1.3V (150W)
Input Impedance	19kOhm (RCA), 20kOhm (Balanced)
Chain Output	Buffered, unity gain
Dimensions (W x H x D)	215 x 75 x 365 mm
Weight	5.5 kg
Power Supply	220V-240V AC
Power Consumption	Standby 6.4W, No signal 23W, 150W output 255W
Cooling	Intelligent fan control
Inputs	Balanced XLR, Unbalanced RCA (phono)
Outputs	Speaker outputs, Chain output
System Control	MC-Bus connections
Enclosure	Die cast chassis
Safety Approvals	EN 60065
Safety Precautions	Do not expose to rain or moisture; no user-serviceable parts inside
Maintenance and Cleaning	Disconnect from mains; use a damp cloth, no liquid cleaners
Servicing and Repairs	Authorized Cyrus service centres only; use manufacturer-specified replacement parts

Frequently Asked Questions - aPA7.5 Mono Cyrus Audio

What is the power output of the Cyrus aPA7.5 Mono?

The aPA7.5 Mono delivers 150W RMS into 8 ohms and 240W RMS into 4 ohms, ensuring robust performance for high-quality audio systems.

How many aPA7.5 Mono amplifiers do I need for a stereo setup?

Since the aPA7.5 Mono is a mono amplifier, you need two units for a stereo system - one for the left channel and one for the right channel. For an AV system, up to five units may be required.

What input connections are available on the aPA7.5 Mono?

The amplifier provides both balanced XLR and unbalanced RCA (phono) inputs, selectable via a rear-panel switch. Balanced connections are recommended for long cable runs or when the amplifier is placed near a loudspeaker.

How does the Chain output work on the aPA7.5 Mono?

The Chain output allows you to connect multiple aPA7.5 Mono amplifiers to a single preamplifier channel, enabling bi-amplification or tri-amplification. It is buffered and works with both RCA and XLR inputs.

What is the MC-Bus connection used for?

The MC-Bus connection creates a system control loop, allowing unified power control from a Cyrus preamplifier, integrated amplifier, or surround decoder. Multiple aPA7.5 Monos can be daisy-chained for remote standby control.

How does the cooling fan operate in the aPA7.5 Mono?

The internal fan uses an Intelligent Power Controller. It turns off during idle and progressively speeds up as the amplifier warms up, reaching maximum speed at maximum temperature. This keeps fan noise minimal during quiet passages.

What should I do if there is no sound from one speaker?

Check for a short circuit in the speaker connections. The protection circuit will activate and the red Mute light will stay lit. Disconnect power, verify all connections, and consult the troubleshooting guide if the issue persists.

Can I use the aPA7.5 Mono for bi-amping?

Yes, the Chain output enables bi-amping or tri-amping by connecting two or more aPA7.5 Mono amplifiers per channel. All Cyrus power amplifiers have matched voltage gain, so no setup adjustments are needed.

What is the power consumption of the aPA7.5 Mono in standby?

In standby mode, the amplifier consumes only 6.4W. When on but with no signal, it consumes 23W; at 150W output, it consumes 255W, making it energy-efficient for a high-power amplifier.

How should I clean and maintain the Cyrus aPA7.5 Mono?

Always unplug the unit before cleaning. Use a damp cloth; never use liquid or aerosol cleaners. For servicing, only contact authorized Cyrus service centres - there are no user-serviceable parts inside.

USER MANUAL aPA7.5 Mono Cyrus Audio

Cyrus aPA7.5 Mono

Fig 1

Fig 2

Fig 3

IMPORTANT! Read before operating this equipment!

CAUTION: The exclamation mark is to draw your attention to important instructions and safety procedures in this manual.

ATTENTION: The lightning flash warns you of the risk of electrical shock presented by components inside this product. Unauthorised personnel must not open this unit.

WARNING: To reduce the risk of electrical shock do not remove any unit covers or panels. There are no user serviceable parts in this product.

WARNING: To reduce the risk of electric shock, do not expose this equipment to rain or moisture.

HEED WARNINGS: All warnings on the product and in the operating instructions should be adhered to.

READ ALL THE INSTRUCTIONS: All the safety and operating instructions should be read before the product is operated.

RETAIN INSTRUCTIONS: The safety and operating instructions should be retained for future reference.

FOLLOW INSTRUCTIONS: All operating and use instructions should be followed.

CLEANING: Unplug this product from the mains before cleaning. Do not use liquid or aerosol cleaners. Use a damp cloth for cleaning.

WATER AND MOISTURE: Do not use this product near water - for example, near a bath tub, wash bowl, kitchen sink, or laundry tub, in a wet basement; or near a swimming pool and the like. The product must not be exposed to dripping or splashing and no objects filled with liquids, such as vases, shall be placed on the product.

HEAT: The product should be situated away from heat sources such as radiators, stoves, or any other products (including amplifiers) that produce heat.

VENTILATION: Slots and openings in the cabinet are provided for ventilation, to ensure reliable operation of the product and to protect it from overheating and these openings must not be blocked or covered. The openings should never be blocked by placing the product on a bed, sofa, rug or similar surface. This product should not be placed in a built-in installation such as a bookcase or rack unless proper ventilation is provided or the manufacturer's instructions have been adhered to.

OBJECT OR LIQUID ENTRY: Never push objects of any kind into this product through openings as they may touch dangerous voltage points or short-out parts that could result in a fire or electric shock.

ACCESSORIES: Do not place this product on an unstable cart, stand, tripod, bracket, or table. The product may fall, causing serious injury to a child or adult, and serious damage to the product. Use only with a cart, stand, tripod, bracket or table recommended by the manufacturer, or sold with the product. Any mounting of the product should follow the manufacturer's instructions, and should use a mounting accessory recommended by the manufacturer.

ATTACHMENTS: Do not use attachments not recommended by the product manufacturer as they may cause hazards.

MOVING THE PRODUCT: A product and cart combination should be moved with care. Sudden stops, excessive force, and uneven surfaces may cause the product and cart to overturn.

POWER SOURCES: This product should be operated only from the type of power source indicated on the marking label. If you are not sure of the type of power supply to your home, consult your product dealer or local power company. For products intended to operate from battery power, or other sources, refer to the operating instructions.

OVERLOADING: Never overload wall outlets, extension cords, or integral convenience receptacles. This can result in an increased risk of fire or electric shock.

POWER CORD PROTECTION: Power supply cords should be routed so that they are not likely to be walked on or pinched by items placed upon or against them, paying particular attention to cords at plugs, convenience receptacles, and the point where they exit from the product.

NAKED FLAMES: No naked flame sources, such as candles, must be placed on this product.

LIGHTNING: For added protection for this product during a lightning storm, or when it is left unattended or unused for long periods of time, unplug it from the wall outlet and disconnect the antenna or cable system. This will prevent damage to the product due to lightning and power-line surges.

CAUTION! POLARISED CONNECTOR (CANADA and USA): To prevent electrical shock, match wide blade of plug to wide slot, fully insert.

Do not alter or remove this plug if it does not fit your mains power socket. Have a suitable socket installed by a competent electrician.

POWER SUPPLY:

Connect the moulded IEC connector of the AC cord supplied plugs into the power inlet ⑨ on the rear of the unit. The mains fuse ⑩ is on the rear panel next to the power switch. It must only be replaced as follows:

U.K. / Europe 230V

T2A 20mm

The mains supply requirement for your Cyrus aPA7.5 Mono is marked on a label on the rear panel. Before connecting, check that this voltage is the same as your mains supply.

230V Products:

Voltage Range

220V-240V

If you move to an area with a different mains voltage, contact your local Cyrus distributor to have your product converted.

NOTE FOR UK CUSTOMERS:

The aPA7.5 Mono is supplied with a power cable terminated by a fused 13A mains plug. This plug should not be removed but if it is removed, dispose of it safely and do not re-use it. To connect a new 13A plug, proceed as follows: Connect the brown wire to the terminal marked L or coloured red. Connect the blue wire to the terminal marked N or coloured black. The internal plug fuse should be 5A.

SERVICING:

Do not attempt to service this product yourself as opening or removing covers may expose you to dangerous voltage or other hazards. Refer all servicing to qualified service personnel.

CONDITIONS REQUIRING SERVICE: Unplug this product from the wall outlet and refer servicing to qualified service personnel when:

• When the power supply cord or plug is damaged.
  • If liquid has been spilled, or objects have fallen into the product.
  • If the product has been exposed to rain or water.
  • If the product has been dropped or damaged in any way.
• If the product does not operate normally by following the operating instructions. (Adjust only those controls that are covered by the operating instructions. Improper adjustment of other controls may result in damage requiring extensive work by a qualified technician to restore the product to its normal operation).
• When the product exhibits a distinct change in performance.

REPLACEMENT PARTS: When replacement parts are required, be sure the service technician has used replacements specified by the manufacturer or have the same characteristics as the original part. Unauthorised substitutions may result in fire, electric shock, or other hazards.

SAFETY CHECK: Upon completion of any service or repairs to this product, ask the service technician to perform safety checks to determine that the product is in proper operating condition.

PRODUCT SERVICE CENTRES:

For product service or technical advice, contact only authorised Cyrus service centres. The Cyrus distributors are listed at the end of this instruction manual.

Welcome to the world of Cyrus!

Congratulations on your choice of Cyrus Hi-fi products. Our state-of-the-art design technology and outstanding quality of manufacture has won countless awards around the world. We are confident that you will derive great pleasure from owning a product from one of the most recognised and respected manufacturers of hi-fi equipment.

Please read these instructions carefully before commencing installation. They provide full guidance to help you install your aPA7.5 Mono safely and correctly.

Preparations for Installation

Before installing the aPA7.5 Mono check that the following items are included in the accessory box.

• Power Cable
  • 4 Loudspeaker plugs
  • 2 MC-Bus cables

After removing these items, please retain the packaging.

Install the aPA7.5 Mono in a well ventilated location away from sources of high temperature, dust or humidity. Never stand the aPA7.5 Mono under another unit or on any surface likely to hamper its cooling or ventilation.

INSTALLATION

Key to the rear panel drawing (Fig.1):

1.	+ Speaker Outputs	7.	Chain Output
2.	- Speaker Outputs	8.	MC-Bus connections
3.	Cooling Fan	9.	IEC Power Inlet
4.	Balanced (BAL) Input	10.	Mains Fuse Holder
5.	RCA (phono)/BAL Input Selector	11	Power Switch
6.	Unbalanced RCA (phono) Input

Connecting to the AC Mains Supply

Connect the socket on the AC Power cable to the Power inlet ⑨ on the rear panel of the aPA7.5 Mono. Now connect the cable to a suitable AC power point.

The mains power switch ® on the rear panel of the aPA7.5 Mono should be left on for normal operation, except when left unattended for a long period when it should be switched off or disconnected from the AC supply.

Identifying System Channels

Each aPA7.5 Mono drives a single speaker. In a stereo system two aPA7.5 Monos are necessary, in an AV system, up to 5 aPA7.5 Mono amplifiers will be necessary. Before proceeding to connect your amplifiers, take some time to organise your system so that you can easily identify which amplifier will be connected to each speaker.

Connecting a Pre-Amplifier or Surround Decoder

Phono (RCA) ⑥ and Balanced input connectors ④ are available to link the aPA7.5 Mono to a pre-amplifier or surround decoder.

Phono (RCA) connections are recommended unless the aPA7.5 Monos are a long distance from the pre-amplifier/decoder, or beside a loudspeaker, then balanced XLR connections ④ may give improved performance.

All aPA7.5 Mono's must use the same method of input connection.

Input Connection via phono (RCA) interconnects

Set the input selector switch ⑤ to RCA. Connect a single phono interconnect from the phono input ⑥ of each aPA7.5 Mono to the corresponding output of the pre-amplifier/decoder.

In the system illustration Fig.4a, a Cyrus Pre aCA7.5 preamplifier is connected to two aPA7.5 Mono amplifiers, one for the left channel and one for the right channel. Input connections are shown using phono interconnects.

Input Connection using Balanced XLR cables

Set the input selector switch ⑤ to BAL. Connect a 3-pin XLR cable from the balanced input ④ of each aPA7.5 Mono to the corresponding XLR output of the pre-amplifier/decoder.

Connecting Loudspeakers

Fitting the loudspeaker plugs

Check for polarity indicators (+ and -) on the loudspeaker cable and fit the plugs provided. Observe any signal directionality markings indicated on the cable. If an arrow is printed on the cable it should point toward the speaker.

If additional or replacement loudspeaker plugs are required for the aPA7.5 Mono ensure that the correct 'BFA' type are purchased.

Connecting the cables

After checking all the assembled cables for polarity they can be plugged into the loudspeakers and amplifiers. The '+' and '-' terminals of each loudspeaker must be connected to the matching '+' and '-' terminals of each amplifier as follows-

Connect the left loudspeaker to the rear panel sockets ① (red speaker plug) and ② (black speaker plug) of the left channel aPA7.5 Mono. Connect the right loudspeaker to the rear panel sockets ① red speaker plug) and ② (black speaker plug) of the right channel aPA7.5 Mono.

Dual outputs are provided for the convenient connection of bi-wiring speaker cables. Fig.4a shows a wiring schematic for a bi-wired stereo system.

Chain Output

The Chain output ⑦ allows more than one aPA7.5 Mono to be connected to each channel of a pre-Amplifier or decoder.

Note: The Chain output is operational whether phono (RCA) or Balanced XLR input connection is made to the aPA7.5 Mono.

Bi-Amplification

The Chain facility can be used with two or more aPA7.5 Mono amplifiers per channel, for Bi/Tri-amping by connecting the Chain output of the first aPA7.5 Mono to the phono inputs of the next aPA7.5 Mono. Such a bi-amplified system provides the sonic benefits of totally separate power amplification for the bass and treble units of the loudspeakers.

In the bi-amplified system illustration Fig.4b, a Cyrus Pre aCA7.5 preamplifier is connected to four aPA7.5 Mono amplifiers - two for the left channel and two for the right channel. Phono input connections are shown.

Note: The Chain output is operational whether phono (RCA) or Balanced XLR input connection is made to the aPA7.5 Mono.

Gain Matching

All Cyrus power amplifiers, and all power amplifier stages in Cyrus integrated amplifiers have the same voltage gain characteristics. This means that you can use the aPA7.5 Mono in conjunction with any Cyrus amplifier for bi-amping, etc. without any set-up adjustments being required.

MC-Bus System Connection (Optional)

Connecting the MC-Bus sockets ⑧ of the aPA7.5 Mono in an MC-Bus system provides unified system power control. An MC-Bus loop is established by connecting single phono cables from the MC-Bus output of one unit to the MC-Bus input of another in a daisy-chain. Complete the loop by returning the MC-Bus output of the final component to the MC-Bus input of the first (see example system connections in Fig.3).

With MC-Bus established you can control the power function of the system from the front panel or remote control of the main Cyrus amplifier or Surround Processor.

OPERATION

Key to the front panel drawing (Fig.2)

1. Standby Switch
2. Standby Light
3. Mute Light

Switching On

When power is applied, the STANDBY key ⑫ may be used for power control. The Standby light ⑬ shows red when the aPA7.5 Mono is in Standby and green when operational.

Remote power control can also be enabled by connecting the MC-Bus sockets ⑧ of the aPA7.5 Mono to a Cyrus system which includes a Preamplifier, Integrated amplifier or Surround decoder. A number of aPA7.5 Monos may be connected in this way to provide remote standby control of all the system power amplifiers.

Mute Indicator

The MUTE Indicator ¹⁴ will glow red if the protector of the aPA7.5 Mono switches in. This occurs for a few seconds following Standby operation or if a temporary overload condition arises. If the MUTE Indicator glows continually, refer to the Troubleshooting Guide.

Cooling

Due to the substantial power of the aPA7.5 Mono, air-cooling is provided via a fan ③. The fan in the aPA7.5 Mono features an Intelligent Power Controller. When the unit is idling the fan turns off. As the amplifier warms up the fan progressively speeds up, reaching maximum speed at maximum temperature. In this way the fan speed is always related to the power output of the unit and fan noise is barely discernible even at low volume levels. In quiet passages and between tracks on a CD, the fan will slow down so as not to encroach on the listening experience.

TROUBLESHOOTING GUIDE

If your aPA7.5 Mono is not operating properly, disconnect the power and check all connections using the notes in this handbook. If problems persist, the checklist below may be helpful.

If you are in doubt, consult your dealer.

No sound from both speakers
Check that the pre-amplifier and the power amplifiers are on.Check that the pre-amplifier and the power amplifiers are not muted.Check that the pre-amplifier responds to front panel commands.Check that the relevant program source is selected.Check that the correct amplifier input is selected.	The standby lights should be green.The red Mute lights should not be lit.Tape Monitor should not be selected.The source device must be operating normally.The RCA/BAL switch must be switched to the appropriate input.
Check that the loudspeakers are connected.	The connection at the terminals of the loudspeakers and the aPA7.5 Mono should be checked.
No sound from one speaker
There may be a short circuit in the speaker connections.	The protection circuit will operate and the red Mute light will stay lit.

Specifications

Power Supply

Voltage: As plate on rear of unit

Power Consumption

Standby....(6.4W)

ON (No Signal)....(23W)

ON (150W)....(255W)

Safety Requirements ...... EN 60065

Enclosure

Dimensions (WxHxD).... 215 x 75 x 365mm

Weight....5.5Kg

Material ....Die cast chassis

Audio Performance

Input Sensitivity (50W 8Ω) RCA....381mV

Input Sensitivity (50W 8Ω) BAL....775mV

Input Sensitivity (150W 8Ω) RCA....660mV

Input Sensitivity (150W 8Ω) BAL 1.3V

Input Impedance (RCA) 19kΩ

Input Impedance (BAL)....20kΩ

Output Power (Continuous) 8Ω ....150Wrms

Output Power (Continuous) 4Ω ....240Wrms

THD+N @2/3 full power....(20Hz - 20kHz 8Ω)....<0.05% (1kHz 8Ω)....<0.004%

Slew Rate (input filter bypassed) 700v/μS

Frequency Response (-3dB)....0.5Hz-130kHz

S/N Ratio (Ref. 150W / 8Ω)...... 114dBA

Chain Output (buffered) ......(unity gain) 660mV

(ref. 660mV RCA input, 1.3V Balanced input.)

Cyrus reserves the right to change all specifications without notice. E & OE

WARRANTY

The warranty card enclosed should be completed by the Dealer and the purchaser and returned to CYRUS or its Distributor within 8 days of purchase. No Dealer or Distributor may vary the terms of this warranty which is personal to the original Purchaser and is not transferable.

Please retain the sales receipt as proof of purchase.

Warranty claims must wherever possible be made through the Dealer from whom the equipment was purchased.

This warranty excludes:

• Damage caused through neglect, accident, misuse, wear and tear, or through incorrect installation, adjustment or repair by unauthorised personnel. Any unauthorised servicing will result in loss of guarantee.
• Liability for damage or loss occurring in transit to or from the purchaser.
• Consequential damage, loss or injury, arising from or in conjunction with this equipment.

Equipment for attention under warranty should be consigned return carriage paid. If returned equipment is found to comply with the published specification, CYRUS reserves the right to raise a charge.

The above conditions do not affect your statutory rights as a consumer.

Spitfire Close, Ermine Business Park, Huntingdon, PE29 6XY

Tel: [phone], Fax: [phone]

E-mail: [e-mail] Internet: www.cyrusaudio.com

AUSTRALIA: Crestmore Pty Ltd.

PO Box 199, North Turramurra, NSW 2074

Tel: [phone] Fax: [phone]

Email: [e-mail]

AUSTRIA: Tepax GmbH

FRANCE: Audio Marketing Services

1 Rue Jean Perrin, Le Blanc Mesnil, Paris, 93150

Tel: [phone], Fax: [phone]

Email: [e-mail]

GERMANY: Tepax GmbH

HUNGARY: Infovox KFT

Terez Korut 31, 1067 Budapest

Tel: [phone], Fax: [phone]

ICELAND: Radiobaer EHF

Armula 38, PO Box 8933, 128 Reykjavik

Tel: [phone] Fax: [phone]

IRELAND: Audio Vision Import Ltd

Acoustic House, John F Kennedy Drive, Nass Road, Dublin 12

Tel: [phone] Fax: [phone]

ITALY: MPI Electronic srl

Via de Amicis 10/12, Cornaredo 20010, Milan

Tel: [phone] Fax: [phone]

KOREA: Sungmin Acoustics Co Ltd

2nd Floor, #559-32, Dobong-Dong, Dobong-Gu, Seoul, 132-010

Tel: + 822 34922586 Fax: + 822 34922588

NEW ZEALAND: Crestmore Pty Ltd

Unit A4, 1066 Great South Road, Mt. Wellington, Auckland

Tel: + 64 9 270 4001 Fax: + 64 9 270 4007

NORWAY: SAS Scandinavia

Industrivej 30, Brondby, DK 2605, Denmark

Tel: [phone] Fax: [phone]

POLAND: Misja Audio

SINGAPORE: Asia Sound Equipment(s) Pte Ltd

1 Coleman Street, #4-49/62 The Adelphi, 179803

Tel: [phone] Fax: [phone]

SLOVENIA: Bofex doo

Ljubljana, Smartinska 152, Hala 5, Ljubljana, 61000

Tel: [phone] Fax: [phone]

SOUTH AFRICA: Hif Fi Specialists (Pty) Ltd

155 Durbon Road, Bellville, 7530

Tel: [phone] Fax: [phone]

SPAIN: EAR SA

Heraclio Fournier 5, Vitoria, 01006

Tel: [phone] Fax: [phone]

SWEDEN: SAS Scandinavia

Industrivej 30, Brondby, DK 2605, Denmark

Telephone: + 45 4343 1777 Fax: + 45 4343 1767