McIntosh C55 2-Channel Solid State Preamplifier - Glass black

Description

The Solid-State Stage: Precision as a Signature

The C55 is a fully solid-state preamplifier, with no vacuum tubes, and its sonic signature reflects that choice: total harmonic distortion measured at 0.005%, a 100 dB high-level signal-to-noise ratio (80 dB MC and 82 dB MM), frequency response +0/-0.5 dB from 20 Hz to 20 kHz (+0/-3 dB from 15 Hz to 100 kHz), and maximum output of 16 V RMS balanced and 8 V RMS unbalanced. Bass control is particularly firm, the noise floor is exceptionally low, and the stereo image is well anchored — three characteristics valued by listeners who follow dense, layered music and expect maximum readability of each part. The volume attenuator is a precision balanced digitally-controlled system with 0.1 dB accuracy for perfect repeatability from one session to the next, and the power supply uses a fully regulated R-core transformer for quiet operation across the full range of volume positions.

The Upgradable DA2 Digital Module: Seven Digital Inputs Including HDMI ARC

The DA2 module is an audiophile-grade Quad Balanced 8-channel 32-bit D/A converter that handles all digital duties. Seven digital inputs: two coaxial, two optical (24-bit / 192 kHz), one USB (DSD512, DXD 384 kHz), one proprietary MCT input for a direct DSD stream from a McIntosh MCT series SACD/CD transport, and one HDMI ARC input that receives TV audio with Dolby Digital and DTS multichannel decoded to stereo. The HDMI ARC input is especially useful: it lets the same speaker pair serve both music and television without switching sources on the preamplifier, without a separate digital cable, and without going through a cinema processor. The DA2 module is physically replaceable in the chassis, which protects the investment as digital format standards continue to evolve. The HDMI ARC input carries audio only — it does not pass video.

Two Adjustable Phono Inputs With Five Selectable Gain Steps

The C55 provides two dedicated phono inputs, each independently configurable as moving magnet (MM) or moving coil (MC), with adjustable capacitance loading, adjustable resistance loading, and selectable gain in five 6 dB steps (40, 46, 52, 58, or 64 dB). Sensitivity is 0.45 mV for MC and 4.5 mV for MM, with a signal-to-noise ratio of 80 dB MC and 82 dB MM. This latitude accommodates both a low-output MC on a high-end tonearm and a high-output MM on a restored vintage table — on the two phono inputs of the same preamplifier. Each configuration is stored and recalled automatically by the on-screen input name, which lets the listener switch from one turntable to the other without re-adjusting anything by hand.

All-Variable Output Matrix, Bi-Amping and Subwoofer Output

Outputs: three balanced XLR variable pairs and three unbalanced RCA variable pairs (all variable — no fixed outputs) are active simultaneously to drive up to three distinct systems. The Main and Output 1 pairs carry adjustable high-pass and low-pass filters for bi-amping a single speaker — for example, a tube amp on the high end and a solid-state amp on the low end, with a user-set crossover point. Output 1 also carries a trim level control to volume-balance two amplifiers of different gain when bi-amping. The Output 2 pair can be configured as stereo (second-room system), mono (one powered subwoofer), or dual mono (two subwoofers) — the C55 is the only solid-state preamplifier in the McIntosh range to carry a dedicated subwoofer output.

The Return of the Processor Loop, 8-Band Analog EQ and Home Theater PassThru

The C55 carries the 8-band analog equalizer that sits at the top of the McIntosh preamplifier range: ±12 dB per band on eight fixed center frequencies, with a full bypass of the tone circuit remembered per input. This is a hardware analog corrector that lets the listener adjust the sonic profile to the room's acoustics or to compensate for a compromised recording, without the phase issues typical of digital filters. The return of the Processor Loop — absent from the last few McIntosh preamplifier generations — also lets an external analog equalizer (like the McIntosh MEN220 or MQ112), a room-correction unit, or an analog tape deck sit in a dedicated tap on the signal path. Home Theater PassThru lets the front-channel signal from a home theater processor pass through the C55 at unity gain so the same speaker pair can serve stereo and cinema.

High Drive Headphone Amplifier With HXD®, Network and Smart-Home

The 1/4-inch headphone output is handled by a discrete High Drive amplifier with the HXD® (Headphone Crossfeed Director) circuit, which restores spatial imaging on headphones by simulating the inter-ear crosstalk present in loudspeaker listening. The C55 connects to an Ethernet network, which unlocks the McIntosh Connect app (iOS and Android) for volume, input, and output selection, and lets McIntoshOS firmware updates arrive automatically. It is Roon Tested (validated by Roon Labs to receive a stream from a Roon Core), Connects with Control4 (native SDDP integration), and Works with Crestron Home (native Crestron integration). The rear panel carries six data ports, an IR input, an RS-232 control input, one main power control jack and four trigger outputs, plus electromagnetic input switching for noise-free changes and Input Level Match ±6 dB per input.

A Preamplifier Hand-Assembled in Binghamton

McIntosh Laboratory shipped its first amplifier in 1949 from Binghamton, New York, and still builds every product by hand at the same site today. The C55 carries the visual signatures of the brand: black glass front panel with fiber-optic illuminated legends, machined aluminum knobs, polished mirror stainless steel chassis with brushed Titanium finish, and two blue Watt Output meters showing the output level in real time. Every unit is tested point by point before leaving the factory and ships with a 3-year limited warranty backed by the authorized McIntosh service network. Standard McIntosh footprint: 17.5 × 7.625 × 16.5 in. (44.45 × 19.4 × 41.9 cm), 28 lb (12.5 kg). Awarded five stars by UK magazine The Ear.

Common Questions

Where does the C55 sit in the McIntosh preamplifier lineup?

The C55 is the direct successor to the C53 and the most feature-complete solid-state stereo preamplifier in the current McIntosh catalog. The C49 remains in the catalog below it, with the DA1 DAC (DSD256, dealer-installed DA2 upgrade available), no 8-band EQ, no dedicated subwoofer output, no Processor Loop. On the tube side, the C2800 is the 16-input equivalent with the DA2 module built in. The C22 Mk V is the purely analog tube preamplifier (7 inputs, two front-panel-adjustable phono). Above them, the C12000 is the reference two-chassis preamplifier with Hybrid Drive™ (tube + solid-state), without a built-in digital section.

How do the C55's outputs work and what about bi-amping?

The three balanced XLR pairs and the three unbalanced RCA pairs are all variable (no fixed outputs) and active simultaneously. The Main and Output 1 pairs carry adjustable high-pass and low-pass filters for bi-amping a single speaker, with a trim level control on Output 1 to volume-balance two amplifiers of different gain. The Output 2 pair can be configured as stereo (second-room system), mono (one powered subwoofer), or dual mono (two subwoofers) — the C55 is the only solid-state preamplifier in the McIntosh range to carry a dedicated subwoofer output.

Which McIntosh amplifier is intended to pair with the C55?

McIntosh places the MC1.25KW first (1,200 W solid-state monoblock, reference of the line), followed by the MC611 (600 W monoblock) and the MC462 (2 × 450 W stereo). The trio covers the common ambitions around the C55: a compact stereo chain with the MC462, or a step up to mono blocks (a pair of MC611s, or a pair of MC1.25KW for a reference chain). The three simultaneously active variable XLR pairs also let you drive two different systems at the same time.

Can the DA2 module be upgraded later?

The DA2 module is physically replaceable in the chassis, as the DA1 module was in the previous generation of McIntosh preamplifiers. If McIntosh releases a future digital module to replace the DA2, the C55 can receive the upgrade at an authorized dealer without being replaced — this is the main advantage of the modular design McIntosh has carried across several preamplifier generations.

What's in the Box

McIntosh C55 stereo preamplifier

McIntosh HR085 remote control

AC power cord

Quick start guide

Owner's manual