Audio T Verdict
The QUAD Artera Stereo is a deceptively compact power amplifier. Beneath the beautifully restrained aluminium and glass casework sits a serious two-channel amplifier delivering 140W per channel into 8 ohms and a substantial 250W into 4 ohms.
At its heart is QUAD's famous Current Dumping topology. A precision low-power Class A amplifier looks after signal accuracy while the high-power current-dumping section supplies the muscle required by the loudspeakers. It is a very different approach from simply building an enormous conventional output stage and chasing the biggest wattage figure possible.
Balanced XLR and conventional RCA inputs make it easy to partner with anything from the matching Artera Pre or Play+ to a suitable streamer, DAC/preamp or preamplifier from another manufacturer. For anyone wanting serious stereo power without stepping up to separate monoblocks, the Artera Stereo remains one of the key amplifiers in the Artera family.
QUAD Artera Stereo Power Amplifier
The QUAD Artera Stereo is a dedicated two-channel power amplifier combining substantial output capability with the latest Artera implementation of QUAD's patented Current Dumping technology.
It delivers 140W per channel into 8 ohms and 250W per channel into 4 ohms, providing considerably more real-world power into lower-impedance loudspeaker loads than the 8-ohm headline figure alone suggests.
- Stereo power amplifier
- Two amplifier channels in one chassis
- QUAD Current Dumping topology
- Precision low-power Class A amplifier section
- High-power current-dumping section
- 140W per channel into 8 ohms
- 250W per channel into 4 ohms
- Balanced XLR inputs
- Single-ended RCA inputs
- Physical RCA/XLR input selector
- 980mVrms RCA input sensitivity
- 10kOhm balanced input impedance
- 15kOhm unbalanced input impedance
- 115dB A-weighted signal-to-noise ratio
- 12V trigger input
- 20-minute selectable auto standby
- Thermal overload protection
- Short-circuit protection
- High-quality speaker binding posts
- Compact 320mm-wide chassis
- 15kg net weight
- Audio T options in Aluminium Black or Aluminium Silver
A Dedicated Stereo Power Amplifier
The Artera Stereo contains two power-amplifier channels but no source selector, DAC, phono stage, streamer or listening-volume control.
It therefore requires a suitable component providing a variable line-level output, such as:
- A dedicated preamplifier
- A DAC with genuine preamplifier functionality
- A network streamer with variable analogue output
- A CD player/DAC with preamplifier output
- An integrated amplifier with a suitable variable pre-out
A Power Amplifier Needs Volume Control Upstream
The Artera Stereo has no volume control of its own. Do not connect an ordinary fixed-output CD player, DAC or streamer directly unless another properly implemented means of controlling listening level exists.
140W Per Channel Into 8 Ohms
QUAD rates the Artera Stereo at 140W per channel into 8 ohms, measured at 1kHz with less than 1% THD.
That is a substantial output for a relatively compact stereo power amplifier and gives useful headroom for musical peaks without requiring separate monoblocks.
250W Per Channel Into 4 Ohms
QUAD's current product information specifies 250W per channel into 4 ohms.
This figure matters because real loudspeakers rarely behave like a simple fixed 8-ohm resistor. Their impedance varies with frequency and can fall considerably below the nominal rating.
An amplifier's ability to increase its available output as impedance falls therefore tells you considerably more about its real-world capability than the 8-ohm wattage alone.
Why the 4-Ohm Figure Matters
A loudspeaker labelled 8 ohms might fall to 4 ohms or below at parts of its frequency response. The Artera Stereo's increase from 140W into 8 ohms to 250W into 4 ohms demonstrates substantial additional power availability as the electrical load becomes more demanding.
Designed for Demanding Loudspeakers
The Artera Stereo was engineered for use with high-quality contemporary loudspeakers and QUAD specifically identifies its own electrostatic loudspeaker designs as suitable partners.
That does not mean every speaker needs 140 or 250 watts. Sensitivity, impedance, listening distance, room size and desired playback level all need to be considered together.
Audio T can help establish whether the Artera Stereo is appropriately matched to your loudspeakers before purchase.
QUAD Current Dumping Technology
The defining feature of the Artera Stereo is QUAD's patented Current Dumping amplifier architecture.
The concept first appeared in the legendary QUAD 405 and takes a different approach from conventional high-power amplification.
Rather than relying on one output stage to provide both ultimate signal accuracy and all the power demanded by the loudspeaker, QUAD divides those responsibilities between two sections.
Precision Class A Amplifier
A very high-quality low-power Class A amplifier is responsible for maintaining the accuracy and finesse of the music signal.
Because this section does not have to provide the full loudspeaker power itself, it can be optimised around signal quality rather than brute-force output capability.
High-Power Current Dumper
A separate high-power current-dumping stage supplies the energy needed to control and drive the loudspeaker.
This allows the amplifier to deliver substantially greater power without asking the precision amplifier alone to handle the complete electrical load.
Precision Bridge Network
The Class A and current-dumping sections are linked through a carefully configured precision network.
The design allows the low-power amplifier to maintain control over output accuracy while the current dumper supplies the additional muscle demanded by the speaker.
Is the Artera Stereo a Class A Amplifier?
Not in the conventional sense of being a 140W-per-channel pure Class A design. QUAD's Current Dumping architecture uses a high-quality low-power Class A amplifier together with a separate high-power current-dumping stage. It is best described by its actual Current Dumping topology rather than reducing the complete amplifier to a single conventional Class designation.
Why Current Dumping?
Traditional high-power amplifier stages have to balance factors including distortion, output-device matching, bias stability, efficiency and heat.
QUAD's Current Dumping approach separates the precision and high-current roles, allowing the individual amplifier sections to concentrate on different aspects of the job.
One practical result is that the Artera Stereo can provide substantial power while remaining relatively compact and cool-running compared with some conventional high-output amplifier architectures.
Born From the QUAD 405
Current Dumping was introduced in the QUAD 405, one of the company's most significant historical amplifiers.
The Artera Stereo is not simply a 405 circuit placed inside newer casework, however. It uses an updated implementation developed for the Artera generation, with modern components, power supply, PCB layout and connection options.
Low Distortion
At 100W and 1kHz, QUAD specifies total harmonic distortion at less than 0.003%.
QUAD also provides a wider-band measurement of less than 0.03% at 100W across 20Hz to 20kHz.
Publishing both figures is useful because the second measurement looks beyond the conventional single-frequency 1kHz test.
Wide Frequency Response
The Artera Stereo is specified at:
- -0.5dB: 20Hz to 20kHz, referenced to 1kHz
- -3dB: 20Hz to 70kHz, referenced to 1kHz
The second figure demonstrates that the amplifier's analogue bandwidth extends substantially beyond the conventional audible range.
115dB Signal-to-Noise Ratio
QUAD specifies an A-weighted signal-to-noise ratio of 115dB referenced to 140W.
Low residual noise is important in a power amplifier because whatever leaves the output stage is connected directly to the loudspeakers.
Balanced XLR Inputs
The Artera Stereo provides a stereo pair of balanced XLR inputs.
QUAD paid particular attention to the balanced input implementation and recommends XLR when partnering the amplifier with suitable Artera components offering balanced outputs.
Balanced connection uses separate positive and negative signal conductors plus ground, allowing interference common to both signal lines to be rejected by the receiving circuit.
10kOhm Balanced Input Impedance
QUAD specifies balanced input impedance at 10kOhm.
This is an important figure when checking electrical compatibility with a preamplifier or variable-output source, particularly when mixing components from different manufacturers.
Single-Ended RCA Inputs
Conventional stereo RCA inputs are also provided.
This makes the Artera Stereo straightforward to use with equipment that does not offer a balanced output.
The RCA input sensitivity is 980mVrms and the unbalanced input impedance is 15kOhm.
RCA or XLR?
QUAD strongly advocates using balanced XLR when connecting suitable Artera equipment, but RCA remains a fully supported connection.
Balanced connection can be particularly useful where:
- The preamplifier has a properly implemented balanced output
- Interconnect runs are relatively long
- The installation is susceptible to electrical interference
- A complete balanced signal path is desirable
For shorter conventional domestic installations, a well-designed RCA connection can also perform extremely well.
Physical Input Selector
The rear panel includes a mechanical LINE/XLR input selector.
QUAD specifies:
- Selector extended: RCA Line input active
- Selector pressed: Balanced XLR input active
Always make sure the switch corresponds with the connection you are actually using.
The Natural Partner: QUAD Artera Pre
The QUAD Artera Pre is the dedicated analogue preamplifier designed for the Artera range.
It provides source selection, volume control, MM and MC phono capability, headphone amplification and both RCA and balanced XLR outputs.
Together the Pre and Stereo create a conventional two-box analogue pre/power system.
Partner the Artera Play+
The QUAD Artera Play+ can also drive the Artera Stereo directly.
The Play+ combines CD playback, an ESS ES9018 DAC and variable preamplifier outputs, meaning it can act as the complete source and control centre while the Artera Stereo concentrates solely on driving the speakers.
RCA and balanced XLR connections are available between the two components.
Can You Use Another Preamplifier?
Yes. The Artera Stereo is a standalone power amplifier and does not have to be used with an Artera source or preamplifier.
A suitable third-party preamplifier, DAC/preamp or streamer with variable analogue output can be used provided its output characteristics are compatible with the amplifier's sensitivity and input impedance.
Using a Streamer Directly
A network streamer can feed the Artera Stereo directly if it provides a properly implemented variable analogue output intended for power-amplifier use.
If the streamer has only a fixed analogue output, a preamplifier is required between the two components.
Fixed and Variable Outputs Are Not the Same
Do not assume every streamer or DAC with analogue outputs can safely control a power amplifier. Check that its output is genuinely variable and intended to provide listening-volume control.
12V Trigger Input
The rear panel includes a 12V trigger input.
A compatible Artera source or preamplifier can therefore control the Stereo's standby state automatically.
QUAD recommends using the trigger facility when the amplifier forms part of a complete Artera system.
3.5mm Trigger Connection
The trigger input uses a 3.5mm jack connection.
Within the Artera family, a 3.5mm-to-3.5mm trigger cable can be used between compatible components.
20-Minute Auto Standby
The Artera Stereo provides an optional automatic standby mode.
When activated, the amplifier enters standby after approximately 20 minutes without an input signal or operation.
The function is activated or deactivated by holding the front standby control for approximately three seconds.
Manual Standby
After rear-panel mains power is applied, the amplifier enters standby.
The front standby button brings it into normal operation, at which point the central front-panel illumination becomes active.
Correct Power-Up Sequence
When operating the system manually, the power amplifier should be switched on after the source and preamplifier equipment.
When shutting the system down, switch the power amplifier off before the upstream components.
Keep the system volume at minimum while switching equipment on or off.
Thermal Overload Protection
The Artera Stereo incorporates a thermal protection system.
If the amplifier is grossly overloaded for an extended period, a thermal switch can interrupt its AC supply.
Once the cause has been addressed, operation can be restored from the front standby control.
Short-Circuit Protection
QUAD also documents protection against short-circuited loudspeaker outputs and other gross overload conditions.
In protection mode the front backlight turns off and the power indicator flashes.
Protection Does Not Replace Proper Ventilation
QUAD explicitly warns that the protection circuitry does not necessarily protect the amplifier from seriously inadequate ventilation. Give the Artera Stereo adequate space around the chassis and do not install it in a tightly enclosed cabinet.
Runs Warm During Normal Use
The amplifier is designed to become warm during normal operation.
It should be installed on a sturdy shelf or table with sufficient free space for airflow.
Do not stack other equipment directly on top of the amplifier.
Speaker Connection and Phasing
The rear panel provides high-quality binding posts for the left and right loudspeakers.
Maintain consistent polarity:
- Amplifier positive/red to speaker positive/red
- Amplifier negative/black to speaker negative/black
Correct phasing helps preserve a stable central stereo image and proper bass response.
Bi-Wiring
The QUAD manual specifically reminds users to take additional care with phase when bi-wiring compatible loudspeakers.
If you are unsure how your speaker terminals should be configured, Audio T can advise on both conventional single-wiring and bi-wiring arrangements.
750W Maximum Power Consumption
Maximum power consumption is specified at 750W.
This is a maximum electrical-consumption figure rather than the amount the amplifier continuously draws during normal listening.
Less Than 0.5W Standby Consumption
Standby consumption is specified at less than 0.5W.
15kg Construction
The Artera Stereo weighs 15kg.
Despite a compact 320mm width, this is a substantial piece of amplification and should be installed on suitably strong equipment furniture.
Compact 320mm Chassis
The Artera Stereo measures:
- Width: 320mm
- Height: 158mm
- Depth: 338mm
This is considerably narrower than the traditional 430mm Hi-Fi format while still providing ample space internally for substantial power-amplifier circuitry and cooling.
Aluminium and Glass Construction
Like the other Artera components, the Stereo combines substantial aluminium casework with sculpted side sections and a decorative glass top.
The glass top is supplied separately within the packaging and QUAD recommends fitting it after all rear-panel connections have been made.
Audio T Finish Options
This Audio T product record currently offers:
- Aluminium Black
- Aluminium Silver
Artera Stereo or Artera Mono?
The two power amplifiers share the Artera philosophy but are designed for substantially different output requirements.
Artera Stereo
- Two channels in one chassis
- 140W per channel into 8 ohms
- 250W per channel into 4 ohms
- One amplifier required for stereo
- Balanced and RCA inputs
- 15kg
Artera Mono
- One channel per chassis
- 300W into 8 ohms
- 400W into 4 ohms
- Two amplifiers required for stereo
- Balanced and RCA inputs
- 13kg per amplifier
The Artera Stereo is the simpler and more compact solution for the majority of systems. A pair of Artera Monos becomes relevant when considerably greater output capability and complete physical separation of the amplifier channels are required.
Artera Stereo or QUAD 303?
QUAD 303
- 50W per channel into 8 ohms
- 70W per channel into 4 ohms
- 10A maximum output current
- Bridgeable to mono
- Classic 33/303 design language
Artera Stereo
- 140W per channel into 8 ohms
- 250W per channel into 4 ohms
- Current Dumping architecture
- Dedicated high-power stereo design
- Artera aluminium and glass casework
The 303 is ideal for customers attracted to the compact 33/303 architecture and its modular bridged upgrade route. The Artera Stereo starts from a considerably higher stereo power level in a single chassis.
Who Is the Artera Stereo For?
The Artera Stereo makes particular sense for:
- Systems requiring substantially more power than a typical integrated amplifier
- Less sensitive loudspeakers
- Speakers presenting lower-impedance loads
- Larger listening rooms
- Customers already using a dedicated preamplifier
- Owners of a high-quality streamer or DAC with variable output
- Artera Play+ owners wanting separate power amplification
- Artera Pre owners
- QUAD electrostatic loudspeaker systems where appropriate
Key Features
- QUAD Artera Stereo
- Dedicated stereo power amplifier
- Two-channel architecture
- QUAD Current Dumping topology
- Low-power Class A precision amplifier
- High-power current-dumping section
- Precision combining network
- 140W per channel into 8 ohms
- 250W per channel into 4 ohms
- Less than 0.003% THD at 100W / 1kHz
- Less than 0.03% THD at 100W / 20Hz-20kHz
- 20Hz to 20kHz response at -0.5dB
- 20Hz to 70kHz response at -3dB
- 115dB A-weighted signal-to-noise ratio
- Balanced XLR inputs
- Single-ended RCA inputs
- 980mVrms RCA input sensitivity
- 10kOhm balanced input impedance
- 15kOhm unbalanced input impedance
- Physical LINE/XLR selector
- 12V trigger input
- Selectable 20-minute auto standby
- Thermal overload protection
- Short-circuit protection
- High-quality speaker binding posts
- 750W maximum power consumption
- Less than 0.5W standby consumption
- 320mm chassis width
- 15kg net weight
- Aluminium Black Audio T option
- Aluminium Silver Audio T option
Frequently Asked Questions
Is the QUAD Artera Stereo still current?
Yes. QUAD continues to maintain the Artera Stereo as a current product within its Artera Series.
Is this the Artera Stereo or Artera Mono?
This product is the two-channel QUAD Artera Stereo power amplifier.
How powerful is the Artera Stereo?
QUAD rates it at 140W per channel into 8 ohms and 250W per channel into 4 ohms.
Is 140W the total output or per channel?
It is 140W per channel into 8 ohms.
How many channels does the amplifier have?
Two. One Artera Stereo is a complete stereo power amplifier.
Do I need two Artera Stereo amplifiers?
No. A single unit contains both left and right amplifier channels.
What is QUAD Current Dumping?
It is an amplifier architecture in which a high-quality low-power amplifier maintains signal accuracy while a separate high-power current-dumping stage provides the power required by the loudspeaker.
Is the Artera Stereo pure Class A?
No. Its Current Dumping architecture includes a low-power Class A precision amplifier working together with a separate high-power current-dumping section.
Was Current Dumping used in the QUAD 405?
Yes. The technology was first introduced in QUAD's famous 405 power amplifier and has subsequently been developed through later generations.
What is the THD at 100W?
QUAD specifies less than 0.003% at 100W and 1kHz.
What is the wider-band THD figure?
Less than 0.03% at 100W measured across 20Hz to 20kHz.
What is the frequency response?
QUAD specifies -0.5dB from 20Hz to 20kHz and -3dB from 20Hz to 70kHz, both referenced to 1kHz.
What is the signal-to-noise ratio?
115dB A-weighted, referenced to 140W.
Does it have balanced XLR inputs?
Yes. A stereo pair of balanced XLR inputs is fitted.
Does it have RCA inputs?
Yes. A stereo pair of conventional single-ended RCA inputs is also provided.
Which input does QUAD recommend?
QUAD strongly recommends balanced XLR when using compatible Artera equipment with a balanced output.
What is the RCA input sensitivity?
980mVrms.
What is the balanced input impedance?
10kOhm.
What is the RCA input impedance?
15kOhm.
What is the balanced input sensitivity?
QUAD does not publish a separate balanced-input sensitivity figure in the current Artera Stereo specification, so Audio T does not invent one.
How do I switch between RCA and XLR?
The rear-panel LINE/XLR selector chooses the active input. The extended position selects RCA and the pressed position selects XLR.
Does it have a volume control?
No. It requires a suitable preamplifier or another component providing a properly implemented variable analogue output.
Can I connect the Artera Pre?
Yes. It is the natural dedicated analogue preamplifier partner for the Artera Stereo.
Can I connect the Artera Play+ directly?
Yes. The Play+ provides variable RCA and balanced XLR preamplifier outputs and was designed to partner Artera power amplification.
Can I use a streamer directly?
Yes, if the streamer provides a suitable variable analogue preamplifier output. A fixed-level source requires a preamplifier.
Can I use a different manufacturer's preamplifier?
Yes, provided its output level and impedance are suitable for the Artera Stereo's inputs.
Does it have a 12V trigger?
Yes. A rear 12V trigger input allows compatible source or preamplifier equipment to control standby operation.
Does it have auto standby?
Yes. When activated, the amplifier enters standby after approximately 20 minutes without input signal or operation.
Can auto standby be disabled?
Yes. The feature is user selectable.
Does it have thermal protection?
Yes. A thermal switch can interrupt the AC supply if the amplifier is grossly overloaded for an extended period.
Does it have short-circuit protection?
Yes. QUAD documents protection against short-circuited loudspeaker outputs and gross overload conditions.
Does the protection system mean ventilation doesn't matter?
No. QUAD specifically warns that seriously inadequate ventilation may still cause problems. The amplifier needs suitable free space around it.
Does it run hot?
QUAD states that the amplifier is designed to run warm during normal operation. Current Dumping also allows substantial output from a relatively compact chassis.
Can I bi-wire my speakers?
QUAD's manual discusses bi-wiring and stresses correct phase. Whether bi-wiring is worthwhile depends on the loudspeaker and cable arrangement.
How much power does the amplifier consume?
Maximum power consumption is specified at 750W.
What is standby consumption?
Less than 0.5W.
How large is the Artera Stereo?
320mm wide, 158mm high and 338mm deep.
How much does it weigh?
15kg net.
Which finishes does Audio T currently offer?
The current Audio T product record lists Aluminium Black and Aluminium Silver.
What is the difference between Artera Stereo and Artera Mono?
The Artera Stereo contains two channels and delivers 140W per channel into 8 ohms or 250W per channel into 4 ohms. The Artera Mono is a single-channel amplifier delivering 300W into 8 ohms or 400W into 4 ohms, so two Monos are required for stereo.
Related QUAD Products and Audio T Guides
Why Buy the QUAD Artera Stereo From Audio T?
A power amplifier should be chosen around the loudspeakers and preamplifier it will actually be used with, rather than by looking at wattage alone. Speaker sensitivity, impedance, room size, listening distance, source output level and the choice between RCA and balanced XLR can all affect the final result.
Audio T can demonstrate the Artera Stereo with suitable speakers, check electrical matching with your existing preamplifier or streamer and help decide whether the Stereo or a pair of Artera Monos makes more sense for your system.
- In-store demonstrations
- Loudspeaker matching
- Speaker sensitivity and impedance advice
- Preamp and power-amplifier matching
- Artera Pre demonstrations
- Artera Play+ system demonstrations
- RCA versus balanced XLR guidance
- Input-sensitivity matching
- Streamer and DAC/preamp integration
- Artera Stereo versus Artera Mono comparison
- 12V trigger setup
- Speaker-cable and termination advice
- Bi-wiring guidance where appropriate
- Equipment-support advice
- Ventilation and placement guidance
- Ongoing after-sales support
Contact your local Audio T store to arrange a demonstration or discuss whether the QUAD Artera Stereo is the right power amplifier for your preamplifier, room and loudspeakers.