Audio T Verdict
The ATC SCA2 is a reference analogue pre-amplifier designed to reveal the quality of connected sources without adding an obvious character of its own.
Fully discrete Class A circuitry, exceptionally low distortion and a bandwidth extending beyond 500kHz provide the transparency, timing and dynamic freedom required by high-performance active speakers and separate power amplifiers.
Two balanced XLR inputs, six unbalanced RCA inputs and both balanced and unbalanced variable outputs give the SCA2 considerable system flexibility. Its high-current output stages are also designed to drive difficult amplifier inputs and longer interconnect runs.
The optional SPH2 phono module adds extensively configurable moving-magnet and moving-coil playback, although it converts one of the six RCA line inputs. Digital inputs, streaming and headphone listening are not part of the SCA2’s focused all-analogue design.
ATC SCA2 Reference Stereo Pre-Amplifier
The ATC SCA2 is the company’s highest-performance stereo pre-amplifier and has remained in continuous production since 1996.
It is designed as the control centre for ATC’s high-level active loudspeakers and separate power amplifiers, while remaining compatible with suitable source components and amplification from other manufacturers.
Source selection, signal conditioning and volume control are handled within a fully discrete analogue circuit built by ATC in the United Kingdom.
What Does a Pre-Amplifier Do?
A pre-amplifier selects between connected music sources and controls the signal level passed to the next stage of the system.
With passive loudspeakers, the SCA2 connects to a separate power amplifier, which supplies the current required to drive the speakers.
With active loudspeakers, the power amplifiers and electronic crossovers are built into the speaker cabinets, allowing the SCA2 to connect directly to their line-level inputs.
The SCA2 Does Not Drive Passive Speakers Directly
The SCA2 does not contain a loudspeaker power amplifier or speaker terminals. Passive speakers require a suitable separate power amplifier between the pre-amplifier and loudspeakers.
Fully Discrete Class A Circuitry
The SCA2 uses discrete low-noise Class A circuitry throughout its main signal path.
Individual transistors and supporting components are selected for their specific roles rather than relying on general-purpose audio integrated circuits for the principal gain stages.
ATC’s design aims to preserve low-level detail, transient speed and tonal accuracy while keeping noise and distortion extremely low.
Exceptional Output Drive
High-current output stages allow the SCA2 to drive demanding amplifier inputs and longer interconnect cables without losing control or stability.
This is particularly valuable when active loudspeakers are positioned several metres from the source equipment or when a power amplifier is installed closer to the speakers.
ATC specifies a maximum balanced output of 17V RMS and an unbalanced output of 8.5V RMS into a 600-ohm load.
Wide-Bandwidth Analogue Design
The SCA2’s circuit bandwidth extends from direct current to beyond 500kHz at the stated minus 3dB points.
This does not mean that ultrasonic frequencies form part of normal music reproduction. The wide bandwidth is intended to minimise phase shift and preserve clean transient behaviour throughout the audible range.
Total harmonic distortion is specified below 0.0005 percent, with an A-weighted signal-to-noise ratio greater than 108dB under ATC’s stated test conditions.
Two Balanced XLR Inputs
Two stereo pairs of balanced female XLR inputs are provided for compatible source components.
Balanced connections can reduce susceptibility to electrical interference, particularly where source equipment is separated from the pre-amplifier by longer cables.
Suitable sources may include streamers, DACs and CD players equipped with balanced analogue outputs.
Six Unbalanced RCA Inputs
Six stereo pairs of unbalanced RCA inputs allow conventional analogue sources to be connected.
These inputs can accommodate compatible streamers, CD players, DACs, tuners and other equipment with fixed analogue line outputs.
The SCA2 is an analogue pre-amplifier, so digital sources require their own analogue outputs or a separate digital-to-analogue converter.
Optional SPH2 MM and MC Phono Stage
The optional ATC SPH2 internal phono module supports compatible moving-magnet and moving-coil cartridges.
Gain, resistive loading and capacitive loading can be configured to suit a wide variety of cartridge requirements, including low-output moving-coil designs.
Installing the internal phono module converts one stereo RCA line input for record playback, leaving five unbalanced line inputs alongside the two balanced inputs.
Phono Setup Must Match the Cartridge
Cartridge output, recommended gain, resistance and capacitance should be confirmed before the phono module is configured.
Incorrect settings can result in excessive noise, restricted dynamics, distortion or an inaccurate tonal balance.
Balanced and Unbalanced Pre-Amplifier Outputs
The SCA2 provides one stereo pair of balanced male XLR outputs and one stereo pair of unbalanced RCA outputs.
Both output types follow the main volume control and can connect to compatible power amplifiers or active loudspeakers.
The balanced XLR output is the natural connection for ATC active speakers and suitably equipped power amplifiers, particularly where longer signal cables are required.
Two Stereo Tape Outputs
Two fixed-level stereo RCA tape outputs are provided for compatible recording equipment or other components requiring an unaltered source-level signal.
These outputs do not follow the main listening-volume control and must not be connected directly to conventional power-amplifier or active-speaker inputs.
Precision Input Switching
Input selection is handled by precision gas-filled, gold-plated relays.
Relay switching keeps signal paths short and provides reliable source selection without passing delicate audio signals through conventional mechanical selector contacts.
Billet Aluminium Remote Control
A substantial infrared remote control allows principal functions to be operated from the listening position.
The SCA2 does not depend on a network connection, mobile application or cloud service for normal operation.
Partnering ATC Power Amplifiers
The SCA2 is an ideal partner for the
ATC P2 dual-mono stereo power amplifier
,
which provides more than 300W per channel for demanding passive loudspeakers.
The smaller
ATC P1 power amplifier
provides more than 150W per channel and may be more appropriate for medium-sized rooms and less demanding speaker systems.
Balanced XLR connections allow the SCA2 to feed either power amplifier using a fully balanced signal path.
Partnering ATC Active Loudspeakers
Active loudspeakers contain their own power amplifiers and electronic crossovers, allowing the SCA2 to connect directly to each speaker.
Suitable Audio T options include the
ATC SCM50ASL
,
ATC SCM50ASLT
and
ATC SCM100ASL
.
Each active loudspeaker requires its own mains supply and balanced signal cable from the pre-amplifier.
CA2 Mk2 or SCA2?
ATC CA2 Mk2
- Discrete Class A analogue circuitry
- Five unbalanced RCA line inputs
- Built-in configurable MM and MC phono stage
- Headphone output
- Unbalanced variable outputs
- Compact and straightforward system control
View the ATC CA2 Mk2
ATC SCA2
- ATC’s reference stereo pre-amplifier
- Two balanced and six unbalanced line inputs
- Balanced and unbalanced variable outputs
- Optional extensively configurable SPH2 phono stage
- Higher maximum output capability
- Designed for reference active and passive systems
System Matching
Well Suited To
- ATC active loudspeaker systems
- ATC P1 and P2 power amplifiers
- Balanced and unbalanced analogue sources
- High-performance pre and power systems
- Longer balanced interconnect runs
- Turntables using the optional SPH2 module
- Reference-level analogue music systems
Check Before Buying
- No loudspeaker power amplifier is included
- No digital inputs or internal DAC
- No network streaming or Bluetooth
- No headphone output is listed
- The SPH2 phono stage converts one RCA line input
- Active speakers require individual mains connections
- Cartridge settings must be configured correctly
Setup Guidance
- Connect equipment with every component switched off
- Begin with the listening volume set low
- Use balanced outputs for longer cable runs where practical
- Confirm phono settings before playing records
- Keep signal cables away from mains leads
- Allow ventilation around connected power amplifiers
- Check active-speaker input sensitivity and wiring
Browse our range of
Hi-Fi amplifiers
,
passive and active loudspeakers
,
music streamers
,
turntables
,
phono stages
and
analogue interconnects
, or explore the complete
ATC range at Audio T
.
Key Features
- ATC’s reference analogue stereo pre-amplifier
- In continuous production since 1996
- Fully discrete Class A low-noise circuitry
- High-current output stages
- Bandwidth extending beyond 500kHz
- Two stereo balanced XLR line inputs
- Six stereo unbalanced RCA line inputs
- One stereo balanced XLR variable output
- One stereo unbalanced RCA variable output
- Two fixed stereo RCA tape outputs
- Optional configurable SPH2 MM and MC phono module
- Precision gas-filled, gold-plated input relays
- Billet aluminium infrared remote control
- Suitable for active loudspeakers and power amplifiers
- Hand built in the United Kingdom
- Six-year ATC warranty, subject to current terms
Frequently Asked Questions
Can the SCA2 drive passive speakers?
Not directly. Passive loudspeakers require a suitable separate power amplifier between the SCA2 and the speakers.
Can it connect directly to active loudspeakers?
Yes. Its balanced or unbalanced variable outputs can feed compatible active loudspeakers.
How many source inputs does it provide?
It provides two stereo balanced XLR inputs and six stereo unbalanced RCA inputs.
Does the SCA2 include a phono stage?
A configurable internal SPH2 moving-magnet and moving-coil phono module can be fitted, converting one RCA line input for record playback.
Does it provide balanced outputs?
Yes. It provides one stereo pair of balanced male XLR outputs alongside one unbalanced RCA output pair.
Does it include digital inputs or streaming?
No. The SCA2 is an all-analogue pre-amplifier, so digital sources require their own analogue output or a separate DAC.
Which ATC power amplifier matches the SCA2?
The ATC P2 is its principal reference partner, while the smaller P1 may suit less demanding passive-speaker systems.
How large and heavy is the SCA2?
It measures 102mm high, 440mm wide and 353mm deep, and weighs 6.85kg.
Why Buy From Audio T?
- ATC active-speaker and power-amplifier matching advice
- Comparison with the ATC CA2 Mk2
- Balanced and unbalanced connection guidance
- Moving-magnet and moving-coil cartridge setup
- Streamer, DAC and CD-player matching
- Long interconnect and cable-planning advice
- Complete active and passive system demonstrations
- Equipment-support and installation guidance
- Ongoing setup and system-upgrade support
Contact your local Audio T store
to discuss matching the ATC SCA2 with your sources, active loudspeakers or separate power amplifier.