Audio T Verdict
The Arcam A50 Signature is far more than an anniversary edition with a different badge. Created to mark 50 years of Arcam amplification, it introduces the company's first fully dual-mono Class G integrated amplifier and sits firmly at the top of the Radia separates range.
With 150W per channel into 8 ohms, substantial reserves into lower impedances and completely independent amplifier sections for the left and right channels, the A50 Signature is designed for serious loudspeakers and systems where control, headroom and separation matter just as much as the headline power figure.
It is remarkably well equipped too. HDMI eARC, USB-C audio, optical and coaxial digital inputs, a fully differential ESS ES9039Q2M DAC, three RCA line inputs, a balanced XLR input and a new Class A phono stage supporting both moving-magnet and moving-coil cartridges make it capable of sitting at the centre of a very sophisticated system without immediately requiring additional boxes.
Bluetooth 5.4 adds aptX Lossless, Snapdragon Sound, LE Audio, Auracast and wireless headphone transmission. What the A50 Signature deliberately does not include is a full network-streaming platform or room correction. For customers who want their streaming and amplification kept separate, pairing it with a dedicated source such as the Arcam ST25 makes a great deal of sense.
The A50 Signature Is Not a Network Streamer
Bluetooth is built in, but the A50 Signature does not contain the Wi-Fi, Ethernet, streaming-service platform or Dirac Live processing found in Arcam's SA35 and SA45 streaming amplifiers. For integrated network playback, add a suitable dedicated streamer such as the Arcam ST25.
Arcam A50 Signature Dual-Mono Class G Integrated Amplifier
The Arcam A50 Signature is a flagship stereo integrated amplifier created to celebrate 50 years of Arcam amplifier design and development in Cambridge.
Rather than recreating an amplifier from the company's past, Arcam has used the anniversary to introduce a new architecture. Developed in collaboration with company co-founder John Dawson, the A50 Signature is the first Arcam integrated amplifier to combine Class G amplification with a fully dual-mono internal layout.
Each channel effectively operates as its own amplifier section, with independent circuitry, power regulation, reservoir capacitors, Class G lifter stage, output-stage heatsink and dedicated transformer winding.
- Flagship Arcam Radia integrated amplifier
- Created to mark Arcam's 50th anniversary
- Designed in Cambridge, UK
- Developed with Arcam co-founder John Dawson
- First Arcam fully dual-mono Class G integrated amplifier
- 150W per channel into 8 ohms
- 220W per channel into 4 ohms at 1kHz
- 0.002% harmonic distortion at the stated measurement condition
- ESS ES9039Q2M DAC
- Fully differential digital conversion architecture
- USB-C audio up to 32-bit/384kHz
- HDMI eARC and ARC
- Optical and coaxial S/PDIF digital inputs
- Three stereo RCA line inputs
- One stereo balanced XLR input
- Class A moving-magnet and moving-coil phono stage
- Wired headphone output
- Bluetooth 5.4 reception and transmission
- aptX Lossless and aptX HD
- Snapdragon Sound
- LE Audio and Auracast
- RS232 and trigger control
- Remote control included
- Plastic-free packaging
Arcam's First Fully Dual-Mono Class G Integrated Amplifier
The most important part of the A50 Signature is inside the case.
Although both channels share a single physical chassis, the left and right amplifier sections have been deliberately separated. Each channel uses its own PCB, output stage, Class G lifter circuitry, regulation, reservoir capacitors and dedicated transformer winding.
The power supply is positioned centrally, with analogue, digital and power circuitry carefully separated within the amplifier. Even the rear-panel speaker terminals sit towards opposite sides of the chassis in keeping with the internal left/right architecture.
What Does Dual-Mono Mean?
A dual-mono amplifier separates the left and right audio channels more comprehensively than a conventional shared stereo layout. The aim is to reduce interaction and crosstalk between channels while allowing each side of the amplifier to respond independently to the demands of its loudspeaker.
150W per Channel into 8 Ohms
The A50 Signature delivers 150W per channel into 8-ohm loudspeakers with both channels driven across the full 20Hz to 20kHz audio range at Arcam's stated 0.5% THD measurement condition.
That provides substantial headroom for larger rooms, demanding floorstanding loudspeakers and systems where realistic listening levels require considerably more than entry-level amplifier power.
Power alone does not determine whether an amplifier and loudspeaker will work well together, however. Loudspeaker sensitivity, impedance behaviour, room size, listening distance and preferred volume are all important.
220W per Channel into 4 Ohms
Arcam specifies 220W per channel into a 4-ohm load at 1kHz.
The increase in available output as impedance falls demonstrates useful power-supply and output-stage capability, particularly with loudspeakers whose impedance is lower or more demanding than the nominal 8-ohm figure might suggest.
The 4-Ohm Power Figure Is Measured at 1kHz
The 150W figure is specified with both channels driven from 20Hz to 20kHz into 8 ohms. The 220W figure is measured into 4 ohms at 1kHz and should not be presented as a full-bandwidth 4-ohm measurement.
How Arcam Class G Works
Class G amplification is designed to combine the refinement associated with operating an amplifier from a relatively low-voltage supply with the ability to call upon considerably greater power when musical peaks demand it.
Rather than running the entire amplifier continuously from the highest available supply voltage, additional voltage is brought into operation when required.
The principle allows Arcam to deliver substantial output without the heat and electrical inefficiency that would result from attempting to operate an equally powerful amplifier continuously in Class A.
Independent Class G Lifter Stages
The A50 Signature takes Arcam's Class G approach further by giving each channel its own Class G lifter stage as part of the dual-mono architecture.
The left and right channels therefore have their own supporting power circuitry rather than relying on one common amplifier section to deal with both loudspeaker loads.
ESS ES9039Q2M DAC
The A50 Signature introduces a new digital conversion stage based around the ESS ES9039Q2M DAC.
Arcam operates the DAC in a fully differential configuration and supports it with an ESS reference voltage regulator.
The internal converter handles compatible USB-C, HDMI, optical and coaxial digital sources, allowing a streamer, television, computer, CD transport or other digital source to connect directly to the amplifier.
USB-C High-Resolution Audio
The USB-C audio input supports compatible PCM signals at sample rates up to 384kHz.
Supported rates include:
- 44.1kHz
- 48kHz
- 88.2kHz
- 96kHz
- 176.4kHz
- 192kHz
- 352.8kHz
- 384kHz
Supported digital word lengths are 16, 24 and 32 bits.
When Is USB-C Useful?
USB-C provides a direct digital connection from a compatible computer or other USB audio source to the A50 Signature's internal DAC. This avoids the need for a separate USB DAC where the source and operating system support standard USB audio output.
Optical and Coaxial Digital Inputs
Conventional S/PDIF digital connections are provided for products such as CD transports, network streamers and other compatible digital sources.
The non-USB digital inputs support compatible sample rates up to 192kHz, including 44.1, 48, 88.2, 96, 176.4 and 192kHz.
This allows older and newer digital equipment to make use of the A50 Signature's internal ESS conversion stage.
HDMI eARC and ARC
HDMI eARC and ARC make the A50 Signature considerably easier to integrate with a modern television.
A compatible TV can send its audio back to the amplifier through the HDMI connection, allowing the Arcam and a pair of passive loudspeakers to handle television, films, games and streaming-app sound without requiring a separate soundbar.
Why Use a Stereo Amplifier with a Television?
For customers who primarily care about two-channel sound, using the same amplifier and loudspeakers for music and television can simplify the room and make much better use of an existing Hi-Fi system.
Three RCA Analogue Line Inputs
Three stereo RCA line inputs accommodate conventional analogue source components.
Suitable sources might include:
- CD players
- Network streamers
- External DACs
- Tuners
- Cassette decks
- Other compatible line-level equipment
Balanced XLR Analogue Input
A stereo balanced XLR input is also provided for compatible source equipment.
This is particularly useful with higher-end source components offering balanced analogue outputs and allows the A50 Signature to form part of a fully balanced source connection where appropriate.
An XLR connection is not automatically superior in every domestic system, so comparing it with RCA where both are available remains worthwhile.
Built-In Class A MM and MC Phono Stage
Vinyl playback has received considerably more attention than on the lower Radia integrated amplifiers.
The A50 Signature incorporates a newly developed phono stage operating in Class A and supporting both moving-magnet and moving-coil cartridges.
This means many turntables can connect directly without requiring a separate external phono preamplifier.
Moving-Magnet Cartridges
The published moving-magnet input impedance is 47k ohms with 100pF capacitance.
Arcam specifies the phono frequency response as 20Hz to 20kHz within approximately 1dB of the RIAA curve.
Moving-Coil Cartridges
The A50 Signature also provides moving-coil cartridge support.
Because moving-coil cartridges can vary considerably in output level and electrical requirements, cartridge matching should be checked before purchase rather than assuming every MC design presents exactly the same load.
MM and MC Are Different Cartridge Types
Use the correct phono setting for the cartridge fitted to your turntable. A moving-magnet cartridge should not be treated as moving coil, or vice versa, simply because both connect through standard phono cables.
Bluetooth 5.4 Wireless Audio
The A50 Signature uses Bluetooth 5.4 and can operate as both an audio receiver and transmitter.
Supported technologies include:
- SBC
- AAC
- aptX
- aptX HD
- aptX Lossless
- Snapdragon Sound
- Bluetooth LE Audio
- Auracast
This allows compatible phones, tablets and other devices to send music wirelessly to the amplifier, while suitable wireless headphones can be used for private listening.
aptX Lossless and Snapdragon Sound
With compatible source equipment, aptX Lossless can provide lossless CD-quality audio over Bluetooth under suitable wireless conditions.
Both ends of the Bluetooth connection must support the appropriate technology. A phone that does not support aptX Lossless may still connect successfully but fall back to AAC, SBC, aptX or another mutually supported codec.
Lossless Bluetooth Requires a Compatible Source
The A50 Signature supporting aptX Lossless does not force every Bluetooth connection to operate losslessly. The transmitting device must support the same codec and the wireless link must meet the required conditions.
Auracast and LE Audio
Bluetooth LE Audio and Auracast extend the A50 Signature beyond conventional one-to-one Bluetooth pairing.
Compatible Auracast receiving products can access an available broadcast from the amplifier, while ordinary Bluetooth transmission remains available for suitable wireless headphones.
Auracast functionality requires compatible receiving equipment.
Wired Headphone Amplifier
A conventional wired headphone output is provided for private listening.
Arcam specifies:
- 2.5V RMS maximum output into 32 ohms
- 5V RMS maximum output into 300 ohms
- Supported headphone load range from 16 ohms to 2k ohms
Actual listening level will also depend on headphone sensitivity and the recording being played.
Wired or Wireless Headphones
The combination of a conventional headphone socket and Bluetooth transmission gives owners a choice between wired and wireless listening.
That can be particularly useful where a favourite pair of wired Hi-Fi headphones is used for critical listening but wireless headphones are preferred for television or casual evening use.
No Built-In Wi-Fi Music Streaming
The A50 Signature should not be confused with the Arcam SA35 or SA45.
It contains a sophisticated DAC and Bluetooth platform, but it is fundamentally a separates integrated amplifier rather than an all-in-one network music player.
There is no integrated Wi-Fi/Ethernet streaming platform for Spotify Connect, TIDAL Connect, Qobuz, AirPlay, Google Cast, Roon or network music libraries.
Add the Arcam ST25 Network Streamer
The Arcam ST25 is a natural network source for the A50 Signature.
It adds high-resolution streaming, internet radio, network-library playback, Spotify Connect, TIDAL Connect, AirPlay, Google Cast, Roon and app control while keeping the streaming circuitry and amplification in separate enclosures.
The ST25 can connect through analogue RCA or through a digital connection if you prefer the A50 Signature's ESS ES9039Q2M DAC to perform conversion.
Why Keep the Streamer Separate?
A separate network player allows the streaming platform and amplifier to be upgraded independently. It also gives each component its own enclosure and power supply rather than combining every function inside one box.
Designed Alongside the Arcam CD25
The A50 Signature was introduced alongside Arcam's new CD25, which is intended as its premium disc-playing partner within the expanded Radia range.
The CD25 provides both balanced XLR and conventional RCA analogue outputs, making it particularly well suited to the A50 Signature's expanded analogue connectivity.
No Dirac Live Room Correction
The A50 Signature does not include Dirac Live.
That distinction is important when comparing it with Arcam's SA35 and SA45 streaming amplifiers, which incorporate network music playback and room-correction processing within the amplifier.
The A50 Signature instead concentrates on the dual-mono amplifier, analogue stages, DAC and source connectivity.
System Control Connections
RS232 and trigger input/output connections allow the A50 Signature to integrate with compatible control systems and other equipment.
Trigger connections can help coordinate power operation between compatible components, while RS232 is useful in more advanced control and custom-installation environments.
Only 99mm High
Despite the dual-mono Class G architecture and substantial power output, the A50 Signature remains relatively low in profile.
Its dimensions are approximately:
- 431mm wide
- 344mm deep, including the speaker terminals
- 99mm high, including the feet
Net weight is approximately 12kg.
Allow Space for Ventilation and Cables
Do not choose an equipment shelf purely from the published 99mm height and 344mm depth. Leave suitable free space around the amplifier for ventilation and allow additional room behind it for mains, loudspeaker, HDMI and source cables.
700W Maximum Power Consumption
Arcam specifies maximum power consumption at 700W under its stated operating conditions.
Standby consumption is less than 0.5W.
The maximum consumption figure should not be interpreted as the amplifier continuously drawing 700W during normal listening.
Plastic-Free Packaging
The A50 Signature is supplied in plastic-free packaging using natural materials that are intended to be easier to dispose of or recycle responsibly.
Supplied accessories include the mains lead, remote control with two AAA batteries, Quick Start Guide and Important Safety Instructions.
A50 Signature or A25+?
Arcam A25+
- Fifth-generation Class G
- 100W per channel into 8 ohms
- 165W per channel into 4 ohms at 1kHz
- ESS ES9018K2M DAC
- USB-C audio
- HDMI eARC
- Moving-magnet phono stage
- Bluetooth 5.4 with aptX Lossless and Auracast
Arcam A50 Signature
- Fully dual-mono Class G architecture
- 150W per channel into 8 ohms
- 220W per channel into 4 ohms at 1kHz
- ESS ES9039Q2M DAC
- USB-C audio
- HDMI eARC and ARC
- Class A MM and MC phono stage
- Balanced XLR analogue input
- Bluetooth 5.4 with aptX Lossless and Auracast
The Arcam A25+ already provides Class G amplification, modern digital inputs and lossless-capable Bluetooth in a very capable integrated amplifier.
The A50 Signature moves considerably further in amplifier architecture, power output, analogue connectivity and vinyl capability. It is particularly relevant where the partnering loudspeakers and source equipment justify the additional performance potential of the fully dual-mono design.
A50 Signature or SA45?
Arcam A50 Signature
- 150W per channel into 8 ohms
- Fully dual-mono Class G architecture
- ESS ES9039Q2M DAC
- Class A MM and MC phono stage
- Balanced XLR input
- USB-C and HDMI eARC
- Bluetooth 5.4
- No integrated network streaming
- No Dirac Live
Arcam SA45
- 180W per channel into 8 ohms
- Fifth-generation Class G amplification
- Integrated high-resolution network streaming
- MM and MC phono stages
- Balanced connections
- HDMI eARC
- Dirac Live Room Correction
- 8.8-inch colour display
- More all-in-one functionality
The Arcam SA45 is the better fit for customers wanting streaming, amplification and room correction in one enclosure.
The A50 Signature takes the more traditional separates route, concentrating on a new dual-mono amplifier architecture and allowing the owner to choose a dedicated network source independently.
Who Is the Arcam A50 Signature For?
- High-quality separates systems
- Demanding standmount and floorstanding loudspeakers
- Medium and large listening rooms
- Turntables using moving-magnet cartridges
- Turntables using compatible moving-coil cartridges
- Balanced analogue source components
- High-resolution USB computer audio
- Television sound through HDMI eARC or ARC
- CD players and digital transports
- Dedicated network streamers
- aptX Lossless-compatible Bluetooth sources
- Wired and wireless headphone listening
- Customers who prefer streaming and amplification in separate components
Who Is It Not For?
- Customers wanting built-in Wi-Fi or Ethernet streaming
- Systems where Spotify Connect, TIDAL Connect or similar services must run directly on the amplifier
- Customers requiring Dirac Live room correction
- Systems requiring surround-sound decoding
- Customers looking for an all-in-one streaming amplifier
- Very simple systems where the additional power and connectivity would go unused
Key Features
- Flagship Radia integrated amplifier
- Arcam 50th-anniversary model
- Designed in Cambridge, UK
- Developed with co-founder John Dawson
- Fully dual-mono architecture
- Class G amplification
- Independent amplifier channels
- Dedicated transformer windings
- Dedicated channel regulation
- Dedicated reservoir capacitors
- Individual Class G lifter stages
- 150W per channel into 8 ohms
- 220W per channel into 4 ohms at 1kHz
- 0.002% stated harmonic distortion
- ESS ES9039Q2M DAC
- Fully differential DAC configuration
- USB-C audio up to 384kHz
- 16, 24 and 32-bit digital audio
- HDMI eARC and ARC
- Optical digital input
- Coaxial digital input
- Three stereo RCA line inputs
- Stereo balanced XLR input
- Class A MM phono stage
- Class A MC phono stage
- Wired headphone output
- Bluetooth headphone transmission
- Bluetooth 5.4
- SBC and AAC
- aptX and aptX HD
- aptX Lossless
- Snapdragon Sound
- Bluetooth LE Audio
- Auracast
- RS232 control
- Trigger input and output
- Remote control included
- Less than 0.5W standby consumption
- Plastic-free packaging
- Five-year Arcam amplifier warranty, subject to manufacturer terms
Frequently Asked Questions
What is the Arcam A50 Signature?
The Arcam A50 Signature is a flagship stereo integrated amplifier created for Arcam's 50th anniversary. It combines fully dual-mono Class G power amplification, an ESS DAC, MM/MC phono stage, analogue and digital inputs, HDMI eARC, USB-C audio and Bluetooth 5.4.
Why is it called the A50 Signature?
The amplifier was introduced to celebrate 50 years since Arcam was founded as A&R Cambridge in 1976. Company co-founder John Dawson collaborated on the project, with his signature appearing on the rear cowl and internal circuit boards.
How powerful is the Arcam A50 Signature?
It delivers 150W per channel into 8 ohms with both channels driven from 20Hz to 20kHz. Arcam specifies 220W per channel into 4 ohms at 1kHz.
What does dual-mono mean on the A50 Signature?
Each stereo channel uses its own amplifier PCB, output stage, Class G lifter circuitry, regulation, reservoir capacitors, heatsink and dedicated transformer winding. This provides substantially greater separation between the left and right amplifier sections.
What is Class G amplification?
Class G uses more than one power-supply level so the amplifier can operate efficiently during ordinary listening while making additional voltage and power available when larger musical peaks demand it.
What DAC does the A50 Signature use?
Digital conversion is handled by an ESS ES9039Q2M DAC operating in a fully differential configuration and supported by an ESS reference voltage regulator.
Does the A50 Signature have USB audio?
Yes. Its USB-C audio input supports compatible PCM signals at sample rates up to 384kHz and bit depths of 16, 24 and 32 bits.
Does the Arcam A50 Signature have HDMI eARC?
Yes. HDMI eARC and ARC allow a compatible television to send audio to the amplifier through an HDMI connection.
Does the A50 Signature have optical and coaxial inputs?
Yes. Optical and coaxial S/PDIF digital connectivity is provided for compatible source equipment, supporting sample rates up to 192kHz.
Does it have balanced XLR inputs?
Yes. The A50 Signature provides a stereo balanced XLR analogue input in addition to three stereo RCA line inputs.
Does the Arcam A50 Signature have a phono stage?
Yes. It includes a newly designed Class A phono stage supporting both moving-magnet and moving-coil cartridges.
Can I use a moving-coil cartridge with the A50 Signature?
Yes. Moving-coil cartridge support is built in. Cartridge compatibility should still be checked because MC designs can vary significantly in electrical output and loading requirements.
Can I use a moving-magnet cartridge?
Yes. The moving-magnet phono input is specified at 47k ohms with 100pF capacitance.
Does the A50 Signature have Bluetooth?
Yes. Bluetooth 5.4 supports audio reception and transmission, with SBC, AAC, aptX, aptX HD, aptX Lossless, LE Audio and Auracast among the supported technologies.
Does it support aptX Lossless?
Yes. aptX Lossless is supported with compatible transmitting equipment and under suitable wireless conditions.
Can the A50 Signature transmit to Bluetooth headphones?
Yes. Its Bluetooth system can operate as an audio transmitter as well as a receiver, allowing compatible wireless headphones to be used.
Can I connect wired headphones?
Yes. The dedicated headphone output supports loads from 16 ohms to 2k ohms and provides up to 2.5V RMS into 32 ohms or 5V RMS into 300 ohms.
What is Auracast?
Auracast is part of the newer Bluetooth LE Audio ecosystem and allows compatible receiving products to access an available wireless audio broadcast. Both the transmitter and receiving equipment must support the technology.
Does the Arcam A50 Signature stream Spotify or TIDAL?
Not directly through a built-in network platform. The A50 Signature provides Bluetooth and extensive digital inputs but requires a separate network streamer for integrated Wi-Fi or Ethernet music services.
Which Arcam streamer suits the A50 Signature?
The Arcam ST25 is a particularly suitable partner, adding high-resolution network playback, major streaming services, internet radio, Roon and app control while keeping the streaming platform in a separate component.
Does the A50 Signature have Dirac Live?
No. Dirac Live room correction is not built into the A50 Signature. Customers wanting integrated Arcam streaming and Dirac Live should also consider the SA35 or SA45.
What is the difference between the Arcam A25+ and A50 Signature?
The A25+ delivers 100W per channel and uses Arcam's fifth-generation Class G architecture. The A50 Signature increases output to 150W per channel, introduces a fully dual-mono amplifier layout, uses the newer ESS ES9039Q2M DAC, adds a balanced analogue input and provides both MM and MC phono support.
What is the difference between the Arcam A50 Signature and SA45?
The A50 Signature is a dedicated separates integrated amplifier with fully dual-mono Class G amplification. The SA45 incorporates network streaming, Dirac Live and a large colour display alongside its amplification. The choice depends largely on whether you prefer separate or integrated streaming.
Can the A50 Signature be used with a television?
Yes. HDMI eARC and ARC are provided for compatible television audio, allowing the main stereo loudspeakers to be used for TV, films and games.
How large is the Arcam A50 Signature?
It measures approximately 431mm wide, 344mm deep including the speaker terminals and 99mm high including the feet.
How much does the A50 Signature weigh?
Net weight is approximately 12kg, with a packed weight of approximately 14kg.
How much ventilation does the A50 Signature need?
It should be installed with adequate free space around the chassis rather than tightly enclosed or covered. Always follow Arcam's installation guidance and avoid placing another component directly over ventilation openings.
What warranty does the Arcam A50 Signature have?
Arcam's global warranty information currently lists amplifiers purchased from authorised resellers with a five-year manufacturer warranty, subject to the manufacturer's warranty terms. This is separate from your statutory consumer rights.
Where is the Arcam A50 Signature designed?
It is designed in Cambridge, UK, continuing the amplifier-engineering heritage that began with A&R Cambridge in 1976.
What comes in the box?
The amplifier is supplied with mains lead, remote control, two AAA batteries, Quick Start Guide and Important Safety Instructions.
Related Arcam Products and Audio T Guides
Why Buy the Arcam A50 Signature From Audio T?
An amplifier at this level deserves to be matched properly. Headline power figures are only one part of the process, and the best results come from considering loudspeaker sensitivity and impedance, room size, listening distance, source equipment and the way you actually listen to music.
Audio T can help compare the A50 Signature with other Arcam amplifiers, choose suitable loudspeakers and sources, check turntable cartridge compatibility and decide whether a separate streamer such as the ST25 or an all-in-one alternative such as the SA45 makes more sense for your system.
- Friendly specialist Hi-Fi advice
- In-store demonstrations where available
- Amplifier and loudspeaker matching
- Moving-magnet and moving-coil cartridge advice
- Digital-source and DAC guidance
- USB-C computer-audio advice
- HDMI eARC system setup
- Bluetooth and wireless-headphone guidance
- A25+, A50 Signature and SA45 comparisons
- ST25 streamer system planning
- Part-exchange options
- Home demonstration options where appropriate
- Ongoing after-sales support
Contact your local Audio T store to discuss the Arcam A50 Signature, suitable partnering equipment or arranging a demonstration when stock becomes available.