ATC SIA2-150 All-Analogue Integrated Amplifier

The ATC SIA2-150 combines discrete pre-amplifier circuits derived from the company’s reference SCA2 with the grounded-source MOSFET power-amplifier technology used throughout ATC’s active loudspeakers and separate power amplifiers.

It delivers 150W per channel into 8 ohms and provides five stereo analogue inputs, a dedicated headphone amplifier, remote control and multiple analogue outputs within a single full-width enclosure.

Its entirely analogue design is intended for systems built around turntables, CD players, music streamers, tuners, tape equipment and external digital-to-analogue converters.

150W per Channel with Both Channels Driven

ATC specifies a maximum continuous output of 150W per channel into an 8-ohm load at one percent total harmonic distortion, measured with both stereo channels operating.

Measuring both channels together provides a meaningful indication of the amplifier’s ability to maintain its output during normal stereo playback.

The power supply and output stages are designed to maintain control through demanding low-frequency passages and wide musical peaks rather than simply producing a high headline figure.

Discrete MOSFET Class A/B Output Stages

The power-amplifier section uses ATC’s grounded-source MOSFET Class A/B circuit topology.

Related amplification technology is used in ATC’s active loudspeakers and separate power amplifiers, where low distortion, wide bandwidth and reliable drive into real loudspeaker loads are central to the design.

The SIA2-150 is intended to reproduce both large dynamic contrasts and quieter musical detail without imposing an obviously warm, bright or heavily processed character.

Discrete Class A Input Stages

The pre-amplifier section uses discrete low-noise Class A input circuitry derived from ATC’s separate SCA2 pre-amplifier.

The input stage is designed to preserve low-level information before the signal reaches the volume control and power-amplifier section.

This contributes to the amplifier’s ability to reproduce fine instrumental texture and spatial detail as well as large-scale musical dynamics.

Five Stereo Analogue Inputs

Five stereo RCA line inputs allow several analogue source components to remain connected simultaneously.

Suitable sources include CD players, music streamers, tuners, cassette decks, external DACs and phono stages with conventional line-level outputs.

The word “phono” is sometimes used to describe the physical RCA connector. These inputs are line-level connections and do not provide the specialised amplification and equalisation required by a turntable cartridge.

Designed for Analogue Sources

The SIA2-150 does not contain digital inputs or an internal digital-to-analogue converter.

A CD player or streamer with analogue outputs can connect directly. A digital transport or other source providing only a digital output will require a suitable external DAC.

Browse our digital-to-analogue converters for compatible digital-source options.

Adding Music Streaming

Network streaming is not built into the amplifier, but it can be added through a suitable external music streamer.

A streamer with its own analogue output connects directly to one of the five RCA inputs. A digital-only streamer can be used with an external DAC before the signal reaches the amplifier.

Browse our range of music streamers for suitable system options.

Dedicated Headphone Amplifier

A dedicated headphone-amplifier circuit feeds the front-panel 6.35mm connection.

This allows compatible wired headphones to be used without adding a separate headphone amplifier to the system.

Headphone sensitivity and impedance vary considerably, so particularly unusual or demanding designs should be assessed through a demonstration.

Pre-Amplifier Output

A stereo RCA pre-amplifier output allows the SIA2-150 to control a compatible external power amplifier.

This provides a future development path in which the SIA2-150 continues to handle source selection and volume control while a separate amplifier powers the loudspeakers.

Suitable ATC options include the ATC P1 power amplifier and the more powerful ATC P2 dual-mono power amplifier .

Dedicated Subwoofer Output

A separate stereo RCA output is provided for connection to a compatible active subwoofer or subwoofer system.

The subwoofer’s crossover frequency, level and phase should be adjusted to suit the main loudspeakers, listening room and preferred seating position.

Browse our Hi-Fi subwoofers for suitable options.

Tape Output

A separate stereo RCA tape output is provided alongside the pre-amplifier and subwoofer outputs.

This can support compatible recording equipment or other analogue components requiring a dedicated line-level feed.

Wide-Bandwidth Circuit Design

ATC specifies a frequency response extending from below 2Hz to beyond 280kHz at the stated minus 3dB points.

The wide circuit bandwidth is intended to preserve clean transient response and accurate phase behaviour throughout the audible frequency range.

Total harmonic distortion is specified below 0.0008 percent under ATC’s stated measurement conditions, with an A-weighted signal-to-noise ratio greater than 112dB.

Remote Control

The supplied infrared remote provides control of principal functions from the listening position.

The amplifier does not depend on a mobile application, internet account or external cloud service for normal operation.

Loudspeaker Matching

The SIA2-150 is a natural partner for ATC’s passive loudspeakers and can also drive compatible designs from other manufacturers.

The ATC SCM7 , ATC SCM11 and ATC SCM19 are strong standmount options for rooms of different sizes.

The three-way ATC SCM40 floorstanding speakers provide greater bass extension and dynamic scale while remaining within ATC’s stated amplifier guidance.

Larger passive Classic Series speakers should be assessed carefully according to room size, listening distance and required playback level. Systems requiring greater sustained output may benefit from the ATC P2 power amplifier.

SIA2-100 or SIA2-150?

SIA2-150 or Separate Pre-Amplifier and Power Amplifier?

System Matching

Browse our Hi-Fi amplifiers , stereo speakers , music streamers , CD and SACD players , turntables , phono stages , digital-to-analogue converters and interconnects and speaker cables , or explore the complete ATC range at Audio T .

Key Features

• All-analogue stereo integrated amplifier
• 150W per channel into 8 ohms with both channels driven
• Discrete grounded-source MOSFET Class A/B output stages
• Discrete low-noise Class A input stages
• Five stereo RCA line inputs
• Stereo RCA pre-amplifier output
• Dedicated stereo RCA subwoofer output
• Separate stereo RCA tape output
• Dedicated headphone amplifier
• Front-panel 6.35mm headphone connection
• Infrared remote control
• Wide-bandwidth analogue circuit design
• Low distortion and high signal-to-noise performance
• Stereo loudspeaker binding posts
• Hand-built in the United Kingdom
• Warranty extendable to six years following qualifying registration

Frequently Asked Questions