Audio T Verdict
The ATC P1 is a purpose-built stereo power amplifier for customers who want greater control, dynamic range and system flexibility than many integrated amplifiers can provide.
Its dual-mono construction and grounded-source Class A/B output stages deliver more than 150W per channel into 8 ohms with both channels operating. The result is ample headroom for a wide range of passive loudspeakers, including ATC’s SCM models.
Balanced XLR and unbalanced RCA inputs make the P1 easy to partner with a suitable pre-amplifier, streamer or DAC with variable outputs. Its neutral presentation is designed to reveal the source and recording rather than impose an obvious amplifier character.
Customers should remember that the P1 is a power amplifier only. It has no source selection, volume control, phono stage, DAC or streaming platform, so a suitable pre-amplifier or variable-output source is essential.
ATC P1 Dual-Mono Stereo Power Amplifier
The ATC P1 is a high-performance stereo power amplifier developed from the amplifier technology used within ATC’s active loudspeakers.
It provides more than 150W per channel into 8 ohms with both channels driven, giving compatible passive loudspeakers the power and dynamic headroom needed for controlled music reproduction.
The P1 can partner an ATC pre-amplifier or a compatible third-party component offering properly controlled analogue pre-amplifier outputs.
A Volume-Controlled Source Is Essential
Never connect a fixed-level source directly to the P1 unless a suitable volume control is present elsewhere in the signal path.
A power amplifier has no conventional listening-volume control and could otherwise send an extremely high signal level to the loudspeakers.
Why Use a Separate Power Amplifier?
A power amplifier performs the high-current task of driving the loudspeakers, while source selection and volume control are handled by a separate pre-amplifier.
Housing these stages separately allows more internal space for the power supply, output devices and heatsinking while isolating sensitive low-level pre-amplifier circuitry from the power-amplifier section.
It also allows either stage to be upgraded independently as the system develops.
Read our
guide to pre-amplifiers, stereo power amplifiers and monoblocks
for a fuller explanation of the different system options.
More Than 150W per Channel
ATC specifies more than 150W of continuous output per channel into an 8-ohm load, measured with both channels operating.
Quoting both channels driven gives a more meaningful indication of stereo performance than a measurement taken with only one channel active.
The additional headroom can help maintain control during musical peaks and reduce the likelihood of the amplifier being pushed into distortion during demanding passages.
True Dual-Mono Construction
The P1 uses a dual-mono layout, with the left and right channels designed to operate as independently as practical within one enclosure.
This allows full power to be delivered simultaneously from both channels while reducing interaction between them through the signal and power-supply paths.
ATC specifies channel crosstalk of better than 100dB between 10Hz and 20kHz, supporting stable stereo separation and precise placement within the soundstage.
Grounded-Source Class A/B Output Stage
The P1 uses ATC’s grounded-source Class A/B output-stage topology, derived from the amplifier modules used in the company’s active loudspeakers.
The circuit is designed to combine high output capability with low distortion, wide bandwidth and controlled transient response.
Large heatsinks provide passive cooling and help maintain stable operation without relying on a cooling fan.
Extremely Wide Bandwidth
ATC specifies a frequency response extending from below 2Hz to beyond 400kHz at the stated minus 3dB points.
Frequencies far above the audible range are not included to reproduce ultrasonic music. The wide circuit bandwidth is intended to support accurate phase response and clean transient behaviour throughout the audible spectrum.
Total harmonic distortion is specified below 0.002 percent under ATC’s stated measurement conditions.
Balanced XLR Inputs
A stereo pair of balanced female XLR inputs is provided for compatible pre-amplifiers and source components.
Balanced connections can be helpful when equipment is separated by longer cable runs or installed in an environment where electrical interference may be present.
The connected pre-amplifier should provide an output level and impedance suitable for the P1’s 2V input sensitivity.
Unbalanced RCA Inputs
A conventional stereo pair of unbalanced RCA inputs is also included.
This allows the P1 to partner a broad range of analogue pre-amplifiers, music streamers, DACs and other components with volume-controlled RCA outputs.
Use one appropriate input connection method and ensure that all equipment is switched off before changing signal cables.
Unbalanced RCA Link Output
The P1 includes a stereo RCA link output that passes the incoming analogue signal onwards to another compatible power amplifier.
This can simplify suitable bi-amplified or tri-amplified systems without requiring multiple output pairs from the pre-amplifier.
The link output is unbalanced and does not provide independent volume control, crossover filtering or a separate listening zone.
Gain Matched with the ATC P2
The P1 is gain matched with the more powerful
ATC P2 power amplifier
.
This allows the two models to be considered together in compatible multi-amplifier systems without introducing a basic gain mismatch between amplifier channels.
Bi-amplification should only be attempted where the loudspeaker manufacturer permits it and the system’s terminal arrangement is fully understood.
Remove Loudspeaker Terminal Links Before Bi-Amplifying
Where a compatible loudspeaker uses separate terminal sections, any factory links must normally be removed before connecting separate amplifier channels.
Incorrect wiring can connect amplifier outputs together and cause equipment damage. Ask your Audio T store for assistance before proceeding.
Matching ATC Pre-Amplifiers
The
ATC CA2 Mk2
is the natural compact partner for the P1, providing analogue source selection, volume control, phono playback and headphone listening.
The reference
ATC SCA2
offers a more substantial pre-amplifier platform for higher-level systems.
A compatible streamer or DAC with a genuine variable pre-amplifier output may also be used, provided its output level, connection type and volume behaviour are suitable.
Matching Passive Loudspeakers
ATC describes the P1 as suitable for a wide range of passive loudspeakers, including models that benefit from generous clean power and strong driver control.
Natural ATC partners include the
ATC SCM7
,
ATC SCM11
,
ATC SCM19
and
ATC SCM40
.
Loudspeaker sensitivity, impedance, room size and listening distance should all be considered alongside the headline amplifier power.
Read Audio T Swansea’s
review of the ATC SCM40 passive loudspeakers
for more information about ATC speaker performance and amplifier matching.
P1 or P2?
ATC P1
- More than 150W per channel into 8 ohms
- True dual-mono construction
- Balanced XLR and unbalanced RCA inputs
- Unbalanced RCA link output
- Suitable for a broad range of passive speakers
- More compact and lighter than the P2
ATC P2
- 300W per channel into 8 ohms
- Greater power and current capability
- Designed for more demanding speakers and rooms
- Gain matched with the P1
- Balanced and unbalanced inputs
- Larger and substantially heavier enclosure
View the ATC P2 power amplifier
P1 or an Integrated Amplifier?
ATC P1 Separates System
- Dedicated enclosure for power amplification
- Choice of partnering pre-amplifier
- Greater flexibility for future upgrades
- Balanced and unbalanced inputs
- Requires additional shelf space and interconnects
Integrated Amplifier
- Pre-amplifier and power amplifier in one enclosure
- Fewer components and cables
- Often easier to install
- May include digital inputs or additional features
- Pre and power stages cannot be changed independently
View the ATC SIA2-100 integrated amplifier
Installation and Ventilation
Position the P1 on a rigid equipment support capable of carrying its 17.55kg weight.
Leave clear space around the amplifier and its heatsinks so heat can escape naturally. Avoid enclosed cupboards, deep piles of equipment or placing heat-sensitive components directly above it.
Connect the pre-amplifier and loudspeakers with all equipment switched off, then begin listening with the pre-amplifier volume set low.
Do Not Obstruct the Heatsinks
Class A/B power amplification generates heat during normal operation. Restricted airflow can increase operating temperature and reduce long-term reliability.
System Matching
Well Suited To
- ATC CA2 and SCA2 pre-amplifiers
- Streamers and DACs with suitable variable outputs
- ATC SCM7, SCM11, SCM19 and SCM40 speakers
- Passive speakers requiring generous clean power
- Stereo pre and power systems
- Compatible bi-amplified installations
- Balanced or unbalanced analogue systems
Check Before Buying
- A pre-amplifier or variable-output source is required
- No source selection or listening-volume control
- No phono stage, DAC or music streaming
- Output is specified into an 8-ohm load
- The amplifier weighs 17.55kg
- Ventilation space is essential
- Bi-amplification requires compatible loudspeakers
Setup Guidance
- Switch off every component before connecting cables
- Use balanced or unbalanced inputs as appropriate
- Check speaker-terminal polarity carefully
- Begin with the pre-amplifier volume low
- Keep signal cables away from mains leads where practical
- Support the amplifier on stable Hi-Fi furniture
- Keep the heatsinks and ventilation area clear
Browse our
Hi-Fi amplifiers
,
passive loudspeakers
,
music streamers
,
digital-to-analogue converters
and
interconnects and speaker cables
, or explore the complete
ATC range at Audio T
.
Key Features
- High-performance stereo power amplifier
- More than 150W per channel into 8 ohms
- Full output specified with both channels driven
- True dual-mono construction
- Grounded-source Class A/B output stages
- Amplifier technology derived from ATC active loudspeakers
- Balanced stereo XLR inputs
- Unbalanced stereo RCA inputs
- Unbalanced stereo RCA link output
- Gain matched with the 300W ATC P2
- Frequency response beyond 400kHz
- Very low distortion and noise
- Large passive heatsinks
- Designed for a wide range of passive loudspeakers
- Hand built in the United Kingdom
- Six-year ATC warranty, subject to current terms
Frequently Asked Questions
How powerful is the ATC P1?
ATC specifies more than 150W per channel into 8 ohms with both channels driven.
Does the P1 include a volume control?
No. It requires a suitable pre-amplifier or source component with a properly controlled variable output.
Does it include digital inputs or streaming?
No. The P1 is an analogue power amplifier with balanced XLR and unbalanced RCA inputs.
Are the XLR inputs balanced?
Yes. ATC specifies one stereo pair of balanced female XLR inputs.
What is the RCA link output for?
It passes the incoming analogue signal to another compatible amplifier for suitable multi-amplifier installations.
Can the P1 be used with the ATC P2?
Yes. ATC gain matches the P1 and P2 so they can be considered together in compatible bi-amplified systems.
Which ATC pre-amplifier matches the P1?
The ATC CA2 Mk2 is its natural compact partner, while the SCA2 provides a reference-level alternative.
How large and heavy is the P1?
It measures 142mm high, 453mm wide and 338mm deep including its terminals, and weighs 17.55kg.
Why Buy From Audio T?
- ATC pre-amplifier and loudspeaker matching advice
- Comparison with the more powerful ATC P2
- Balanced and unbalanced connection guidance
- Pre and power system demonstrations
- Loudspeaker power and impedance matching
- Bi-amplification and terminal-link guidance
- Interconnect and speaker-cable recommendations
- Equipment-support and ventilation advice
- System installation and setup assistance
- Ongoing upgrade support
Contact your local Audio T store
to discuss matching the ATC P1 with your pre-amplifier, loudspeakers and listening room.