McIntosh C55 AC Solid-State- Preamplifier

The C55 AC preamplifier is a pinnacle of sonic excellence, designed for audiophiles, music lovers, and die-hard McIntosh fans alike. A torchbearer of innovation, it takes up the baton from its award-winning predecessor, the C53 AC, and catapults your home audio experience into new realms of sonic nirvana. With precision and craftsmanship, the C55 AC proudly asserts its place as a true industry leader.

Entrances galore

With an impressive 16 inputs (9 analog and 7 digital), the C55 AC becomes the center of your audio universe. The analog inputs include 3 balanced and 4 unbalanced connections, as well as 2 phono inputs configurable for moving coil or moving magnet phono cartridges to connect your turntables. Both phono inputs feature adjustable gain in 6dB steps from 40dB to 64dB and RIAA equalization.

The digital section is housed in the DA2 Digital Audio Module and is powered by an audiophile-grade quad-balanced, 8-channel, 32-bit digital-to-analog converter (DAC). The DA2 offers a range of connections, including an audio-only HDMI Audio Return Channel (ARC)1 input, which takes your TV's sound to a new era through your home stereo system. Dolby® and DTS® multi-channel audio formats are expertly converted into exquisite two-channel audio for an immersive listening experience.

The DA2's six additional digital inputs consist of two coaxial, two optical, one USB, and one MCT input. The USB input supports DSD512 and DXD 384kHz. The coaxial and optical inputs decode digital music up to 24-bit/192kHz for high-resolution audio playback. And to get the best sound quality from the high-definition audio of your SACD collection, the MCT input provides a secure, dedicated DSD connection when paired with the MCT series of SACD/CD transports. The entire DA2 module is upgradeable and could be replaced by a future module should new digital technologies become available.

INNOVATIVE EXITS FOR PERSONALIZED LISTENING

To connect the C55 AC to your power amplifier(s), there are three stereo sets of variable balanced and unbalanced outputs, offering advanced connection flexibility. All three sets of outputs can be active simultaneously, and each can send the audio signal from the source component to three separate audio systems.

Additionally, the main output and output 1 can be used for bi-amping a single speaker system via the integrated adjustable high-pass and low-pass filters. In this configuration, the high-pass outputs could be connected to a tube amplifier and the low-pass outputs to a solid-state amplifier. The adjustable crossover allows you to optimize the performance of your amplifiers according to the specifications of your speakers and your listening preferences. Output 1 offers a trim level control, which allows you to balance the volume of two different amplifiers when bi-amping.

In addition, output 2 can be configured as mono or stereo and can send the audio signal to a stereo audio system in another room, to a single mono subwoofer, or to two separate stereo subwoofers.

RETURN OF THE PROCESSOR LOOP

The C55 AC features the return of the processor loop, something unavailable on previous generations of McIntosh preamplifiers. The processor loop allows you to insert an external signal processor (such as the MQ112 Environmental Equalizer or MEN220 room correction system), dynamic range extender, or other devices without having to place them between the preamplifier and the power amplifier(s). This is generally more convenient and can result in improved performance.

The processor loop is also the perfect place to connect an analog tape recorder, a high-end cassette deck, or a 3-head reel-to-reel device, allowing you to record from a source component and hear the recording just seconds later, so you can monitor your recordings.

NETWORKS FOR CONTROL AND UPDATES

In addition to using the included remote control or the front panel controls, the C55 AC can be connected to your network, unlocking control options through the free Connect app (expected to be available from April 2024). Designed for Android and Apple devices, the Connect app can be used to control key functions of the C55 AC, including volume control and input/output selection.

Select McIntosh source components connected to the C55 AC via a data cable can be partially controlled using the app's Source Control feature. Source Control allows users to manage many functions of the source unit through the app, such as changing radio stations on a tuner or playing a disc on a CD player. This feature provides added convenience for setups that have a second set of power amplifiers and speakers connected to one of the C55 AC's outputs, such as an outdoor system, eliminating the need to enter the house to control its basic functionality.

ADDITIONAL PERFORMANCE FEATURES

8-band analog equalizer for fine-tuning your music with precision, for a personalized sound experience (the equalizer can be bypassed if needed).
High Drive headphone amplifier with Headphone Crossfeed Director (HXD®) technology brings an additional dimension to headphone listening.
Home Theater PassThru for seamless integration into your home theater system.
Has received the Roon Tested award from Roon Labs.
Power Control allows you to easily turn other connected McIntosh components on and off.
Data ports can send remote control commands to connected source components.
Electromagnetic input switching for reliable, noiseless and distortion-free switching.
Level Trim Adjustment to equalize the levels of analog inputs to avoid abrupt changes in volume.
Precisely balanced, digitally controlled damping system for accurate volume control with 0.1dB accuracy.
Fully regulated power supplies and a special R-core current transformer for stable, noise-free operation.
Energy management system that switches off the device after 30 minutes of inactivity (can be deactivated).

EARTH YOUR LISTENING JOURNEY

All this cutting-edge technology is housed in the iconic McIntosh design – a black glass front panel adorned with blue blades, rotary knobs, and an illuminated logo. The polished stainless steel chassis adds a touch of elegance, making it the perfect companion for amplifiers, CD players, turntables, and more. Elevate your sonic journey with the C55 AC preamplifier.

TECHNICAL DATA

• Frequency response
  
  • +0, -0.5 dB from 20 Hz to 20,000 Hz
  • +0, -3 dB from 15 Hz to 100,000 Hz
• Total harmonic distortion: 0.005% from 20 Hz to 20,000 Hz
• Nominal output
  
  • 2.5V unbalanced
  • 5V symmetrical (main output)
  • 450mV (Fixed output)
• Maximum voltage output
  
  • 8V RMS value asymmetrical
  • 16V RMS symmetrical
• Sensitivity (for nominal output)
  
  • High level
  • 450mV unbalanced
  • 900mV symmetrical
  • Phono MM, 4.5mV
  • Phono MC, 0.45mV
• Signal-to-noise ratio (A-weighted)
  
  • High level - 100dB
    (Below nominal output)
  • MM Phono - 82dB
    (Input below 5mV)
  • MC Phono - 80dB
    (Input below 0.5mV)
• Input impedance
  
  • High level
  • 22k Ohm unbalanced
  • 44k Ohm symmetrical
  • Phono 1, 2 (MM and MC): 25, 50,
    100, 200, 400, 1k or 47k Ohm 50
    up to 400pF in 50pF increments
• Maximum input signal
  
  • High level
  • 5V unbalanced
  • 10V symmetrical
  • Phono MM, 80mV
  • Phono MC, 8mV
• Equalizer controls: 25Hz, 50Hz, 100Hz, 200Hz, 400Hz,
  1,000Hz, 2,500Hz and 10,000Hz
• Voltage amplification
  
  • High level to fixed output: 0dB
  • High level to main output: 15dB
  • Phono 1, 2 (MM and MC) Selectable
  • 40dB, 46dB, 52dB, 58dB or 64dB
• Output impedance
  
  • 100 ohms unbalanced
  • 200 Ohm symmetrical
• Headphone load impedance: 100 ohms to 600 ohms
• Digital input sampling rates
  
  • Coaxial: PCM -16Bit, 24Bit - 44.1kHz
    up to 192kHz
  • Optical: PCM - 16-bit, 24-bit - 44.1kHz
    up to 192kHz
  • USB: PCM - 16Bit, 24Bit, 32Bit -
    44.1kHz to 384kHz
  • MCT: PCM, SACD, -16Bit, 24Bit -
    44.1kHz to 192kHz / DXD -
    DXD352.8kHz, DXD384kHz DSD -
    DSD64, DSD128, DSD256, DSD512
  • HDMI: PCM 24Bit, 44.1kHz - 192kHz
    DTS, Dolby Digital
• Current control and trigger output: 12V DC, 25mA
• Power supply:
  
  • Alternating voltages: 100, 110, 120, 220, 230,
    240 volts, 50/60Hz at 75 watts.
  • Standby power consumption: less than 0.5 watts
• Overall dimensions (W x H x D) in mm: 444 x 194 x 419
• Weight: 12.5 kg