Audio T Verdict
The Arcam PA720 is a substantial seven-channel power amplifier designed for high-performance home cinema systems where control, consistency and musical ability matter as much as outright impact.
Its seven identical Class G channels deliver 100W each into 8-ohm loudspeakers or 140W each into 4 ohms with all channels operating. Arcam's design provides a 20W Class A operating region before calling upon the additional Class G power supply for demanding peaks.
Switchable RCA and balanced XLR inputs, passive RCA loop outputs, Ethernet and RS232 control, trigger connections and seven heavy-duty loudspeaker outputs make it suitable for both domestic cinema rooms and professionally integrated systems.
The PA720 does not provide surround decoding, HDMI switching, room correction, volume control or music streaming, so it must be partnered with a suitable AV processor or receiver with pre-amplifier outputs. It also requires plenty of ventilation and a properly rated equipment rack, but correctly installed it provides a powerful and cohesive foundation for an ambitious surround system.
Arcam PA720 Seven-Channel Class G Power Amplifier
The Arcam PA720 provides seven channels of dedicated power amplification for a compatible home cinema or multi-channel audio system.
It receives variable line-level signals from an AV processor, pre-amplifier or AV receiver with suitable pre-out connections and supplies the current needed to drive passive loudspeakers.
All seven amplifier channels are identical, so the connected processor can assign them to front, centre, surround, rear surround or Dolby Atmos height speakers as required.
An AV Processor or Pre-Amplifier Is Required
The PA720 has no source selection, surround decoding, digital-to-analogue conversion, room correction or listening-volume control.
It must receive a properly controlled variable-level signal from a suitable AV processor, receiver or multi-channel pre-amplifier.
Seven Identical Amplifier Channels
Each of the PA720's seven channels uses the same amplifier architecture and provides the same rated output.
There are no lower-powered channels reserved specifically for surround or height duties, helping maintain a consistent presentation as effects, voices and music move around the room.
The AV processor determines the role of each channel. The PA720 itself does not label or restrict a particular amplifier channel to a specific speaker position.
Arcam Class G Amplification
Class G amplification uses more than one power-supply level to combine low-level refinement with the ability to produce substantially greater output when required.
The PA720 operates within its lower-voltage Class A region during quieter and less demanding passages. When the audio signal requires more power, the additional supply is brought into operation.
This allows the amplifier to deliver considerable power without operating continuously at the heat and electrical consumption of a similarly powerful conventional Class A design.
Learn more in our
Audio T guide to Arcam Hi-Fi and Class G amplification
.
20W Class A Operating Region
Arcam specifies a 20W Class A operating region for each PA720 amplifier channel.
A significant amount of ordinary listening may remain within this lower-power region, depending on the loudspeaker sensitivity, room size, listening distance and selected volume.
When a soundtrack demands greater output, the Class G architecture makes the additional supply available without requiring the amplifier to operate continuously at maximum voltage.
20W Does Not Represent the Maximum Output
The 20W figure describes the Class A operating region rather than the PA720's full power capability.
Maximum continuous output is considerably higher and depends on the loudspeaker impedance and number of channels operating.
100W per Channel into 8 Ohms
With all seven channels operating, the PA720 delivers 100W per channel into 8-ohm loudspeakers across the 20Hz to 20kHz audio range at the manufacturer's stated distortion condition.
This provides enough output for many high-quality home cinema loudspeaker systems, including installations where all seven main channels may be called upon simultaneously.
Using a genuine all-channels-driven figure provides a more meaningful indication of multi-channel performance than quoting the output of one channel in isolation.
140W per Channel into 4 Ohms
Output rises to 140W per channel into a 4-ohm load with all seven channels driven.
The 140W figure therefore requires the loudspeaker-impedance qualification and should not be presented simply as seven channels of 140W into any speaker.
Real loudspeaker impedance varies with frequency, so the nominal impedance printed on the cabinet provides only part of the information needed when matching an amplifier.
Read our
amplifier power, impedance and loudspeaker matching guide
for a clearer explanation.
Additional Power with Fewer Channels Driven
When five channels are operating, the PA720 is rated at 110W per channel into 8 ohms or 175W into 4 ohms under the manufacturer's stated measurement conditions.
With two channels operating, output rises to 140W per channel into 8 ohms or 225W into 4 ohms.
The increase is available because the shared power supply is supporting fewer amplifier channels at the same time.
Seven Channels Driven
- 100W per channel into 8 ohms
- 140W per channel into 4 ohms
- Measured across 20Hz to 20kHz
- Representative of a complete seven-channel system
Five Channels Driven
- 110W per channel into 8 ohms
- 175W per channel into 4 ohms
- Useful reference for conventional 5.1 systems
- Manufacturer measurement specified at 1kHz
Two Channels Driven
- 140W per channel into 8 ohms
- 225W per channel into 4 ohms
- Useful for stereo or front-channel use
- Manufacturer measurement specified at 1kHz
Toroidal Power Supply
A substantial toroidal transformer provides the electrical foundation for all seven amplifier channels.
Toroidal transformers can provide strong current delivery while limiting stray magnetic fields when correctly designed and installed.
The power supply is engineered to support genuine multi-channel operation rather than achieving its headline power only with a single channel running.
Parallel Transistor Output Stages
Parallel output transistors help each amplifier channel share the current and thermal demands created by difficult loudspeaker loads and dynamic soundtrack peaks.
This contributes to the PA720's ability to maintain control when several channels are producing significant output simultaneously.
The amplifier should still be matched carefully to the complete loudspeaker system, particularly where low-impedance or low-sensitivity speakers are used.
Acoustically Damped HDA Chassis
The power supply and amplifier circuitry are housed within a rigid, acoustically damped HDA-series enclosure.
The casework provides mechanical support for the transformer, heat-management system, circuit boards and fourteen loudspeaker terminals.
At 18kg, the PA720 requires a firm equipment rack or shelf with sufficient load capacity.
Common Seven-Channel Speaker Layouts
The PA720 can power any seven full-range or height channels assigned by a compatible processor.
Traditional 7.1
- Front left and right
- Centre channel
- Side surrounds
- Rear surrounds
- Powered subwoofer connected to the processor
Dolby Atmos 5.1.2
- Front left and right
- Centre channel
- Two surround speakers
- Two height speakers
- Powered subwoofer connected to the processor
Part of a Larger System
- Selected channels in a 7.1.4 or larger installation
- Front, centre and surround amplification
- Seven height or architectural channels
- Additional power amplifiers complete the layout
The Processor Determines the Speaker Layout
The PA720 does not decode Dolby Atmos, DTS:X or any other surround format.
The connected AV receiver or processor must support the required number of channels and provide the corresponding pre-amplifier outputs.
High-Performance Home Cinema Separates
A dedicated AV processor handles HDMI switching, surround decoding, bass management, digital-to-analogue conversion, room correction and volume control.
The PA720 is then dedicated entirely to supplying power to the connected passive loudspeakers.
Separating processing and amplification can provide greater installation flexibility, more space for the power supply and the option to upgrade either section independently.
Our
guide to planning a home cinema system
explains the differences between AV receivers and processor-and-power-amplifier systems.
Using the PA720 with an AV Receiver
The PA720 can also be connected to the pre-out sockets of a compatible AV receiver.
This allows the external amplifier to power seven selected channels while the receiver handles processing, volume, room correction and any remaining internally amplified speakers.
The receiver must provide suitable variable pre-amplifier outputs for every channel assigned to the PA720.
Recalibrate the System After Installation
Speaker levels, distances, crossovers and room correction should be checked again after adding the PA720.
Do not assume that previously stored calibration settings will remain correct after the amplifier and connections have changed.
Switchable RCA Inputs
Seven unbalanced RCA inputs provide compatibility with conventional AV processors and receiver pre-out connections.
Each input feeds its corresponding amplifier channel and is accompanied by a passive RCA loop-output socket.
RCA input sensitivity is specified as 800mV RMS for 100W output into 8 ohms.
Consider
Chord Company ClearwayX analogue interconnects
for suitable RCA or XLR system connections.
Balanced XLR Inputs
Seven balanced XLR inputs are provided for suitable AV processors and pre-amplifiers.
Balanced connections can provide improved rejection of electrical interference, particularly where long interconnects are required between an equipment rack and power amplifier.
XLR input sensitivity is specified as 1.6V RMS for 100W output into 8 ohms.
Choose RCA or XLR for the Amplifier
The rear input selector configures the PA720 for RCA or balanced XLR operation.
Do not assume that some channels can use RCA while others use XLR simultaneously. Match the selector to the chosen connection type before switching the system on.
RCA Input Sensitivity and XLR Input Sensitivity
The RCA and XLR connections require different input voltages to produce the same amplifier output.
RCA requires approximately 800mV RMS for 100W into 8 ohms, while balanced XLR requires approximately 1.6V RMS.
This is normal for the two connection standards and should not be interpreted as the RCA input being more powerful.
Seven Passive RCA Loop Outputs
OUT1 to OUT7 provide passive copies of the signals connected to the corresponding RCA inputs.
These outputs can pass the same processor signals to another suitable power amplifier or installation component.
No filtering, amplification or additional volume control is applied by the PA720.
The Loop Outputs Work Only with RCA Input Signals
The RCA outputs copy signals received through the seven RCA inputs.
They do not provide converted or looped copies of signals connected through the balanced XLR inputs.
Seven Sets of Loudspeaker Terminals
Each amplifier channel has its own positive and negative loudspeaker binding posts.
Maintain correct polarity throughout the system by connecting each positive amplifier terminal to the positive terminal of its loudspeaker.
Loose strands of bare cable can cause a short circuit between terminals. Professionally terminated banana plugs or spade connectors can provide a safer and more reliable installation where compatible.
The
Chord Company ClearwayX terminated speaker cable
is one suitable option for a high-performance system.
Switch Everything Off Before Connecting Speakers
Disconnect the PA720 and processor from the mains before adding or changing loudspeaker cables.
Check every connection for correct polarity, secure termination and stray cable strands before restoring power.
Not Designed for Bridged Operation
The PA720 provides seven independent amplifier channels and does not include a bridged mono mode.
Do not combine loudspeaker terminals or attempt to turn pairs of channels into higher-powered mono amplifiers.
Customers requiring bridged operation for demanding front speakers should consider the
Arcam PA240 Class G power amplifier
.
Never Combine Amplifier Outputs
Joining two PA720 output channels can cause serious damage to the amplifier and connected loudspeaker.
Every speaker must be connected to one corresponding positive and negative channel pair.
Bi-Amplifying Compatible Loudspeakers
Four PA720 channels may potentially be used to bi-amplify a compatible pair of bi-wireable loudspeakers, leaving three channels available for other duties.
The processor signal must be distributed correctly so that two amplifier channels receive the appropriate left signal and two receive the appropriate right signal.
This is an advanced configuration and should be planned carefully to maintain consistent levels and prevent wiring errors.
Remove the Loudspeaker Jumper Links
Bi-wireable speakers normally have metal links connecting their high-frequency and low-frequency terminals.
These links must be removed before separate amplifier channels are connected. Leaving them fitted can join the amplifier outputs together and cause damage.
Dolby Atmos Height Speakers
The PA720 can power passive in-ceiling speakers, on-ceiling speakers or upward-firing Dolby Atmos modules assigned by a compatible processor.
The
Monitor Audio Bronze AMS 7G Dolby Atmos speakers
provide one possible option for a suitable system.
Height-speaker placement, ceiling construction, crossover settings and room correction all affect the final result.
Adding Amplification Does Not Add Processing Channels
The AV processor must already support the required number of Dolby Atmos channels and provide matching pre-out connections.
The PA720 supplies power but does not increase the processor's decoding capacity.
Ethernet Control
The Ethernet connection allows compatible third-party control systems or computers to monitor and operate the PA720.
Supported functions can include power, standby, muting and status information when correctly configured.
The Ethernet socket is intended for control and automation rather than network music playback.
Ethernet Does Not Provide Music Streaming
The PA720 cannot play music from a NAS drive, streaming service or phone through its network connection.
All audio enters through the RCA or balanced XLR analogue inputs.
RS232 Control
An RS232 port provides wired control and monitoring for compatible computers and home-automation systems.
RS232 can be useful in professionally installed cinema rooms where reliable two-way communication is required.
The control system must be programmed using the appropriate Arcam protocol documentation.
Network and RS232 Control in Standby
Ethernet and RS232 control are disabled by default in the lowest-power standby mode.
They can be enabled for standby operation where remote network or automation wake-up is required.
Enabling network standby increases standby consumption compared with the lowest-power setting.
12V Trigger Input and Output
A trigger input allows a compatible AV processor, receiver or control system to switch the PA720 between standby and operation.
A 12V trigger output rated at up to 100mA can control the power state of another compatible amplifier or system component.
Trigger operation allows a separates system to switch on and off more like a single integrated product.
Trigger Cables Are Not Included
Arcam specifies compatible mono 3.5mm trigger cables.
Check the voltage, polarity and trigger requirements of every connected product before use.
USB Port for Software Updates
The rear USB connection is provided for installing PA720 software updates.
It is not a digital audio input and cannot receive music from a computer, phone, tablet or USB storage device.
USB Audio Is Not Supported
Connecting a computer to the USB port will not make the PA720 appear as a DAC or audio device.
Music must be decoded and volume-controlled by the connected AV processor or pre-amplifier before reaching the PA720.
Front Standby and Mute Controls
The front panel provides power, standby and output-muting controls.
Muting disconnects audio from the loudspeaker outputs without requiring the complete amplifier to be switched off.
The front indicator changes colour to show startup, normal operation, standby, mute and protection conditions.
Automatic Standby
The PA720 enters standby after an extended period without an input signal or user interaction.
The default timeout is 20 minutes and can be disabled by holding the front mute button.
More detailed standby adjustment is available through compatible RS232 or IP control commands.
Protection System
The PA720 monitors internal temperature, loudspeaker short circuits and DC offset conditions.
A flashing white indicator reports excessive temperature, flashing red identifies a detected speaker short circuit and flashing orange indicates DC offset.
The amplifier removes power from the loudspeakers when protection is activated.
Correct the Fault Before Restarting
Do not repeatedly switch the amplifier back on without checking ventilation, loudspeaker cables and system connections.
Contact Audio T if the warning returns after the likely cause has been investigated.
Ventilation and Heat Management
The PA720 is designed to run warm during normal operation and can become hot when several channels are driven at high levels.
Place it on a firm, level and stable surface with generous open space around the ventilation openings.
Arcam recommends more than 300mm of clearance and advises against installing the amplifier inside a closed cabinet without effective ventilation.
Do Not Place Other Equipment on Top
Stacking another component on the PA720 may obstruct airflow and expose the other product to heat from the amplifier.
The equipment rack must also be capable of safely supporting the PA720's 18kg weight.
Keep Turntables Away from the Power Supply
Avoid positioning a turntable directly on top of or immediately beside the PA720.
Phono cartridges can pick up mechanical vibration and electromagnetic hum from substantial amplifier power supplies.
System Matching
Well Suited To
- Dedicated processor and power-amplifier cinema systems
- Upgrading an AV receiver through its pre-out connections
- Traditional seven-channel surround systems
- Dolby Atmos 5.1.2 installations
- Selected channels in larger 7.1.4 systems
- Demanding passive home cinema speakers
- Balanced processors using XLR outputs
- Conventional processors using RCA outputs
- Custom installations using Ethernet or RS232
- Systems requiring 12V trigger integration
Check Before Buying
- A compatible AV processor or receiver is required
- No volume control or source selection
- No HDMI input or video switching
- No surround decoding or room correction
- No built-in DAC or digital audio input
- No music streaming or Bluetooth
- USB is for software updates only
- Ethernet is for control rather than audio
- RCA loop outputs do not copy XLR signals
- Bridged mono operation is not supported
- Substantial ventilation space is required
- The amplifier weighs 18kg
Connection Guidance
- Select either RCA or balanced XLR operation
- Match each processor output to the intended channel
- Maintain correct loudspeaker polarity
- Keep bare cable strands away from other terminals
- Switch all equipment off before changing connections
- Recalibrate the AV processor after installation
- Use the trigger input for coordinated power control
- Use Ethernet or RS232 only with compatible control systems
- Provide more than 300mm of ventilation clearance
- Use a suitably rated equipment rack
Browse our
home cinema amplifiers and AV receivers
,
Hi-Fi and power amplifiers
,
home cinema speakers
and
interconnects and speaker cables
, or explore the complete
Arcam range at Audio T
.
PA720, PA240 and PA410 Comparison
Arcam PA720
- Seven-channel Class G power amplifier
- 100W per channel into 8 ohms
- 140W per channel into 4 ohms
- RCA and balanced XLR inputs
- Ethernet and RS232 control
- Designed for larger home cinema systems
Arcam PA240
- Two-channel Class G power amplifier
- 225W per channel into 8 ohms
- 380W per channel into 4 ohms
- 790W bridged mono operation
- RCA and balanced XLR inputs
- Designed for demanding front speakers
View the Arcam PA240 power amplifier
Arcam PA410
- Four-channel Class AB power amplifier
- 50W per channel into 8 ohms
- 70W per channel into 4 ohms
- Four RCA inputs
- Compact 105mm-high chassis
- Ideal for additional surrounds or height speakers
View the Arcam PA410 power amplifier
Finish
HDA Black
The PA720 uses Arcam's understated HDA-series Black finish with a substantial full-width chassis and minimal front-panel controls.
Key Features
- High-performance seven-channel power amplifier
- Seven identical Arcam Class G amplifier channels
- 20W Class A operating region
- 7 x 100W into 8 ohms with all channels driven
- 7 x 140W into 4 ohms with all channels driven
- 5 x 110W into 8 ohms with five channels driven
- 5 x 175W into 4 ohms with five channels driven
- 2 x 140W into 8 ohms with two channels driven
- 2 x 225W into 4 ohms with two channels driven
- 0.002% harmonic distortion at 80% power
- Toroidal power transformer
- Parallel transistor output stages
- Acoustically damped HDA-series chassis
- Seven unbalanced RCA inputs
- Seven balanced XLR inputs
- Rear selector for RCA or XLR operation
- Seven passive RCA loop outputs
- Seven pairs of loudspeaker binding posts
- Suitable for 7.1 and 5.1.2 systems
- Suitable for selected channels in larger Atmos systems
- Ethernet control and monitoring
- RS232 third-party control
- 12V trigger input
- 12V 100mA trigger output
- USB connection for software updates
- Front power, standby and mute controls
- Automatic standby with 20-minute default timeout
- Temperature, short-circuit and DC-offset protection
- Less than 0.5W low-power standby consumption
- 18kg full-width construction
- HDA Black finish
Frequently Asked Questions
What is the Arcam PA720?
It is a seven-channel power amplifier designed to drive passive loudspeakers from the variable pre-amplifier outputs of an AV processor, receiver or suitable pre-amplifier.
Does the PA720 include surround processing?
No. A separate AV processor or receiver must handle Dolby Atmos, DTS:X, HDMI switching, bass management and room correction.
Does it have a volume control?
No. Listening volume must be controlled by the connected processor, receiver or pre-amplifier.
Can a fixed-output source be connected directly?
Not safely in normal use. A fixed-output source provides no convenient listening-volume control and should connect through a suitable pre-amplifier or processor.
How powerful is the PA720 with all seven channels driven?
It delivers 100W per channel into 8 ohms or 140W per channel into 4 ohms across the 20Hz to 20kHz audio range.
Why is it sometimes described as 7 x 140W?
The 140W figure applies to a 4-ohm loudspeaker load. Output into 8-ohm speakers with all seven channels driven is rated at 100W per channel.
What does Class G mean?
Class G uses more than one power-supply level. The lower supply handles ordinary signals, while the additional supply becomes available when greater output is required.
How much Class A operation is provided?
Arcam specifies a 20W Class A operating region for the PA720.
Are all seven channels identical?
Yes. The AV processor decides which speaker position is assigned to each amplifier channel.
Can it power a complete 7.1 system?
Yes. It can power the seven passive main speakers, while a suitable powered subwoofer connects to the AV processor.
Can it power a 5.1.2 Dolby Atmos system?
Yes. Seven channels can power the front left, centre, front right, two surrounds and two height speakers.
Can it be used in a 7.1.4 system?
Yes, as part of the amplification. A 7.1.4 system requires eleven powered loudspeaker channels, so another suitable amplifier is needed for the remaining four.
Can it add extra processing channels to an AV receiver?
No. It can amplify only channels already decoded and provided through the receiver's pre-out connections.
Does it have balanced inputs?
Yes. Seven balanced XLR inputs are provided alongside seven unbalanced RCA inputs.
Can some channels use RCA and others use XLR?
The rear selector configures the amplifier for RCA or XLR operation. Use one connection type throughout and match the switch to the selected cables.
What are the seven RCA output sockets?
They are passive loop outputs that copy the signals received by the corresponding RCA inputs.
Do the RCA outputs copy XLR input signals?
No. They copy only the corresponding RCA input signals.
Can the PA720 be bridged?
No. Bridged mono operation is not supported.
Can it bi-amplify speakers?
Potentially, using separate channels for the high-frequency and low-frequency terminals of compatible speakers. The speaker links must be removed and the signal routing configured correctly.
Does the Ethernet connection stream music?
No. Ethernet is used for compatible control, monitoring and automation.
What is RS232 used for?
RS232 allows a compatible computer or third-party automation system to monitor and control the amplifier.
Does it support trigger control?
Yes. It has a trigger input and a 12V trigger output rated at up to 100mA.
Are trigger cables included?
No. Suitable mono 3.5mm trigger cables must be purchased separately.
Can music be played through the USB socket?
No. The USB connection is used only for software updates.
Does it enter standby automatically?
Yes. The default timeout is 20 minutes without an audio signal or user interaction. It can be adjusted or disabled.
What do the flashing status lights mean?
Flashing white indicates excessive temperature, flashing red identifies a speaker short circuit and flashing orange indicates detected DC offset.
How much ventilation does it need?
Arcam recommends more than 300mm of clearance and advises against installation in a closed cabinet without effective ventilation.
Can equipment be placed on top?
No. This can obstruct airflow and expose the other component to heat from the amplifier.
How heavy is the PA720?
It weighs 18kg and requires a firm, level and suitably rated equipment rack.
Why Buy From Audio T?
- Home cinema demonstrations where suitable facilities are available
- Advice on choosing an AV processor or receiver with suitable pre-outs
- Traditional surround and Dolby Atmos system planning
- Loudspeaker power, impedance and sensitivity matching
- Comparison with the Arcam PA240 and PA410
- RCA and balanced XLR connection guidance
- Processor-to-amplifier cable recommendations
- Speaker cable and termination advice
- AV channel assignment and recalibration guidance
- Bi-amplification and speaker-link advice
- Ethernet, RS232 and trigger-control setup
- Equipment rack and ventilation planning
- Custom installation and cable-routing support
- Home demonstrations may be available
- Part exchange available on suitable existing equipment
- Ongoing system, calibration and installation support
Contact your local Audio T store
to arrange a demonstration or discuss adding the Arcam PA720 to your home cinema system.