McIntosh MC1502 – Tube Power Amplifier for Stereo Systems

The McIntosh MC1502 is a 2-channel power amplifier for high-quality music systems. As the direct successor to the MC2152 Limited Edition 70th Anniversary tube amplifier, it adopts its fundamental technical orientation and combines it with a more traditional McIntosh design.

Tube Technology with Visible Presence

At the heart of the MC1502 is extensive tube amplification featuring KT88 output tubes and 12AX7A and 12AT7 signal tubes. The tubes are seated on a precisely shaped, mirror-polished stainless steel chassis and protected by a black powder-coated stainless steel wire cage.

Technologies in the MC1502

The MC1502 utilizes McIntosh Unity Coupled Circuit, Unity Coupled Output Transformer, Sentry Monitor™, Solid Cinch™ Speaker Binding Posts, Power Control, Balanced Input, and Unbalanced Input. The Unity-Coupled output transformers ensure that the amplifier can deliver its power appropriately to various speaker connections. Sentry Monitor™ monitors the output current and switches off the amplifier in critical conditions. Air-Pipe Cooling for the KT88 tube sockets, ceramic sockets with gold-plated contacts for the signal tubes, and gold-plated connections complete the technical features.

Connection and Operation in a Hi-Fi System

For connection to a preamplifier, balanced and unbalanced inputs are available. Input operation is selected via a switch on the rear panel. Power Control allows the MC1502 to be turned on and off together with other McIntosh components, such as preamplifiers, CD players, turntables, or music streamers. The Solid Cinch™ Speaker Binding Posts are designed for secure speaker connections.

Protection Functions and Operation Indicator

The MC1502 operates with Sentry Monitor™ Tube Protection. This protection circuit intervenes in critical situations such as impedance mismatch, short circuits at the output terminals, or the failure of an output tube. The small signal tubes are illuminated by LEDs: amber indicates the warm-up phase, green indicates normal operation, and red flashing light indicates the activation of the protection circuit.

Technical Data

General

• Product Type: 2-Channel Tube Power Amplifier
• Dimensions W × H × D: 46.4 × 26 × 53.3 cm
• Weight: 53.5 kg
• Frequency Response: +0, -0.25 dB from 20 Hz to 20 kHz;
• Extended Frequency Response: +0, -3.0 dB from 10 Hz to 70 kHz

Audio

• FTC Output Power: 150 W
• Output Power per Channel: 150 W into 2, 4, or 8 Ohms
• Number of Channels: 2
• Total Harmonic Distortion: maximum 0.5% harmonic distortion at any power level from 250 mW to rated power, 20 Hz to 20 kHz
• Total Harmonic Distortion additionally: <0.20% at 1 W, 20 Hz to 20 kHz
• Signal-to-Noise Ratio: 112 dB below rated output power
• Dynamic Headroom: 1.2 dB
• Damping Factor: >18
• Rated Power Bandwidth: 20 Hz to 20 kHz
• Speaker Impedance: 2, 4, or 8 Ohms
• Input Sensitivity: 1.7 V unbalanced, 3.4 V balanced
• Input Impedance: 47,000 Ohms unbalanced, 20,000 Ohms balanced
• Intermodulation Distortion: maximum 0.5% if instantaneous peak power does not exceed twice the rated output power, 20 Hz to 20 kHz

Circuitry and Tubes

• Circuit Concept: Unity Coupled
• Circuit Type: Tube Circuit
• Output Type: Unity Coupled Output Transformer
• Tube Complement: 8 × KT88 power output tubes, 4 × 12AX7A for input stage and phase inverter, 4 × 12AT7 for voltage amplifier and driver stage
• KT88 Tube Sockets: Air-pipe cooling at the base
• Signal Tube Sockets: Ceramic base with gold-plated contacts
• Mono Bridging: no
• Mono Parallel Operation: no
• Power Meters: no

Connections

• Balanced Inputs: 2
• Unbalanced Inputs: 2
• Speaker Terminals: patented Solid Cinch™ speaker binding posts
• Speaker Outputs: right and left output for Class 2 wiring connections
• Input Selection: balanced / unbalanced via input selector switch
• Power Control Input: present
• Power Control Output: present

Features and Operation

• Remote Switching via Power Control: yes
• Automatic Shut-off / Power Saving Function: present, factory activated
• Tube Illumination: switchable on and off
• LED Indicator for Signal Tubes: Amber for warm-up phase, Green for normal operation, flashing Red when Sentry Protection Circuit is active
• Sentry Monitor™: monitors output current and shuts down if safe limits are exceeded
• Front Panel: not applicable
• Switch for Display Illumination: not applicable
• Multi-channel DB25 Connector: not applicable

Finish

• Chassis Finish: polished stainless steel
• Tube Cover: stainless steel wire cage, black powder-coated
• Illumination of Small Signal Tubes: green, natural
• Inputs and Output Terminals: gold-plated connectors

Power Supply

• AC Voltage Variants ex-works: 100 V / 50–60 Hz / 6.6 A; 110 V / 50–60 Hz / 6.0 A; 120 V / 50–60 Hz / 5.5 A; 127 V / 50–60 Hz / 5.5 A; 220 V / 50–60 Hz / 3.0 A; 230 V / 50–60 Hz / 2.75 A; 240 V / 50–60 Hz / 2.75 A
• Subsequent AC Voltage Conversion: not possible
• Standby Consumption: less than 0.3 W
• Power Control Input: 5–15 VDC, less than 1 mA
• Power Control Output: 12 VDC, 25 mA
• Power Control Output Turn-on Delay: 0.2 seconds after power-on

Dimensions and Weight

• Device Dimensions W × H × D: 46.4 × 26 × 53.3 cm
• Device Weight: 53.5 kg
• Shipping Weight: 61.2 kg
• Shipping Carton W × H × D: 67.3 × 39.4 × 71.1 cm

Scope of Delivery

• McIntosh MC1502
• Cover (stainless steel wire cage)
• Power Cord
• Special Wrench
• Documents

• Anleitung I
• Anleitung II
• Broschüre