History re-issued

The McIntosh MC275 AC continues an amplifier legend whose technical roots date back to early McIntosh developments focusing on low distortion and wide bandwidth. The sixth generation receives an output transformer with increased bandwidth, advanced circuitry, and targeted improvements in thermals and bass control.

Tube amplifier with classic McIntosh character

As a tube power amplifier, the MC275 AC represents a consciously traditional amplifier form that doesn't remain nostalgically stuck. The circuit uses McIntosh Unity Coupling technology and bifilar wound output transformers, designed for low distortion, extended frequency response, and cooler operation of the output tubes.

Flexible integration into high-quality Hi-Fi systems

The MC275 AC offers balanced and unbalanced inputs, allowing it to be integrated into various high-quality system concepts. The more massive connection terminals facilitate a solid connection, while the speaker taps are provided for various connection options in stereo and mono operation.

Operation and use

Operation is via clearly assigned switches for on/off, stereo or mono operation, and the selection between balanced and unbalanced inputs. The durable LEDs illuminate the seven pre-tubes and simultaneously indicate the current status of the amplifier.

Setup with consideration for heat and ventilation

The MC275 AC requires careful placement with adequate ventilation. Due to its size and weight, placement should be thoughtfully planned.

Our assessment

Our recommendation: The MC275 AC fits particularly well into a high-quality, classic Hi-Fi chain, where a separate tube power amplifier is intentionally to be used as a central sound and design element.

Pros and cons at a glance

Reasons to choose the McIntosh MC275 AC:

• McIntosh tube amplifier technology
• sixth generation with updated circuitry
• improved balanced input
• massive connection terminals
• stereo and mono operation possible
• LED illumination of the seven pre-tubes with status indicator
• balanced and unbalanced inputs

Things to know about the McIntosh MC275 AC:

• due to tube technology and weight, careful placement is important
• adequate ventilation is required for operation

Specifications

General

• Product Type: Stereo Power Amplifier / Tube Power Amplifier
• Dimensions W × H × D: 41.9 × 21 × 31 cm
• Weight: 30.5 kg
• Shipping Weight: 34.1 kg
• Frequency Response: +0, -3.0 dB from 10 Hz to 70,000 Hz

Connections

• Inputs: Balanced XLR Inputs and Unbalanced RCA Inputs
• Speaker Outputs: Output jacks for left and right speakers
• Speaker Taps: 4 / 8 / 16 Ohms in Stereo Mode, 2 / 4 / 8 Ohms in Mono Mode
• XLR Pinout: Pin 1 Shield/Ground, Pin 2 “+”, Pin 3 “-”
• Power Connection: Socket for power cable
• Fuse: Main fuse holder on the right side panel

Features and Operation

• Operating Modes: Stereo Mode and Mono Mode
• Mono Mode: referred to as “bridged” and “Mono (Parallel) Mode” in the provided specifications
• Switches: POWER, MODE, INPUTS
• Input Selection: BAL for balanced inputs, UNBAL for unbalanced inputs
• Tube Cover / Protective Grille: removable
• LED Lighting: Illumination of the seven pre-amplifier tubes with status display
• Connection Terminals: more robust connection terminals according to product information
• Input Jacks and Output Binding Posts: gold-plated
• Tube Sockets: ceramic with gold-plated contacts

Audio

• Stereo Output Power: 2 × 75 Watts into 4 / 8 / 16 Ohms
• Mono Output Power: 1 × 150 Watts into 2 / 4 / 8 Ohms
• Rated Power Band: 20 Hz – 20,000 Hz
• Total Harmonic Distortion: 0.5%
• Intermodulation Distortion: 0.5%
• Signal-to-Noise Ratio: 100 dB
• Damping Factor: > 14
• Sensitivity: 1.2 V unbalanced inputs, 2.5 V balanced inputs
• Input Impedance: 90,000 Ohms unbalanced inputs, 180,000 Ohms balanced inputs
• Tube Complement: 3 × 12AX7A, 4 × 12AT7, 4 × KT88/6550

Power Supply

• Voltage Requirement: 100 V, 110 V or 120 V at 50/60 Hz and 3.6 A
• Voltage Requirement: 220 V, 230 V or 240 V at 50/60 Hz and 1.8 A
• Voltage Note: The correct voltage is visible on the right side panel

Setup

• Minimum Clearance for Operation: 55.9 cm Width, 45.7 cm Depth, 53.3 cm Height
• Placement: Table, shelf or furniture possible
• Ventilation: Cool air must be able to flow in through the ventilation holes at the bottom, warm air must be able to escape upwards
• Installation in Cabinet or Enclosure: Quiet-running fan required
  
  

Scope of Delivery

• McIntosh MC275 AC
• Tube Cover
• Power Cable
• Documents

• Sicherheitshinweise
• Anschlüsse
• Anleitung
• Broschüre