McIntosh MA252 – Hybrid Integrated Amplifier
The McIntosh MA252 is a 2-channel Hybrid Drive integrated amplifier that combines the musical character of a vacuum-tube preamplifier with the power and control of a direct-coupled solid-state output stage. The preamplifier section uses two 12AX7A and two 12AT7 vacuum tubes, while the solid-state power amplifier delivers 100 watts per channel into 8-ohm loudspeakers or 160 watts per channel into 4-ohm loudspeakers. Designed as an all-analogue integrated amplifier, the MA252 provides balanced and unbalanced line-level inputs, a dedicated Moving Magnet phono input, a full-range mono subwoofer output and a High Drive headphone amplifier. McIntosh technologies including Power Guard®, Sentry Monitor™ and Monogrammed Heatsinks™ provide protection, reliability and high-current performance.
Key Features
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Hybrid Drive™ Architecture: Combines a vacuum-tube preamplifier stage with a direct-coupled solid-state power amplifier.
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Vacuum-Tube Preamplifier: Uses two 12AX7A and two 12AT7 vacuum tubes housed in protective tube cages.
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Solid-State Power Stage: High-current direct-coupled output section provides substantial speaker-driving capability.
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100W per Channel into 8Ω: Delivers 100 watts continuously to each channel with both channels operating.
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160W per Channel into 4Ω: Increased output into lower-impedance 4-ohm loudspeakers.
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All-Analogue Design: Focused on analogue audio without an internal DAC or digital audio inputs.
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Four Analogue Inputs: Includes two unbalanced RCA inputs, one balanced input and one Moving Magnet phono input.
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Moving Magnet Phono Stage: Built-in MM phono input allows compatible turntables to connect without a separate phono preamplifier.
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Mono Subwoofer Output: Full-range mono output allows integration with a compatible powered subwoofer.
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High Drive Headphone Amplifier: Dedicated 1/4-inch headphone output supports headphones with impedances from 20Ω to 600Ω.
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Power Guard®: Monitors the amplifier output and helps prevent harsh clipping that could damage connected loudspeakers.
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Sentry Monitor™: Protects the output stage against potentially damaging operating conditions.
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Monogrammed Heatsinks™: McIntosh heatsinks are connected to high-current output transistors for efficient thermal management.
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Bass & Treble Controls: Independent tone adjustments provide ±10dB control in precise 1dB steps.
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Tone Bypass: Tone controls can be bypassed when a direct signal path is preferred.
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Input Level Matching: Individual source levels can be adjusted to provide more consistent volume when switching inputs.
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OLED Display: Displays source selection and relevant operating settings.
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Remote Control: Input selection and major operating functions can be controlled remotely.
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Polished Stainless-Steel Chassis: Classic McIntosh construction is combined with styling inspired by the MC275.
Amplifier Specifications
| Amplifier Type |
Hybrid Integrated Amplifier |
| Number of Channels |
2 |
| Preamplifier Stage |
Vacuum Tube |
| Power Amplifier Stage |
Solid State |
| Output Type |
Direct Coupled |
| Power Output – 8Ω |
100W per Channel |
| Power Output – 4Ω |
160W per Channel |
| Rated Power Band |
20Hz – 20kHz |
| Total Harmonic Distortion |
0.03% Maximum |
| Dynamic Headroom |
1.8dB |
| Speaker Load Impedance |
8Ω / 4Ω |
Vacuum-Tube Preamplifier
| 12AX7A Tubes |
2 |
| 12AT7 Tubes |
2 |
| Total Vacuum Tubes |
4 |
| Preamplifier Technology |
Vacuum Tube |
| Tube Protection |
Protective Tube Cages |
| Power Amplifier Technology |
Solid State |
| Hybrid Drive™ |
Yes |
Frequency Response
| Frequency Response (+0 / -0.5dB) |
20Hz – 20kHz |
| Frequency Response (+0 / -3dB) |
10Hz – 100kHz |
| Rated Power Band |
20Hz – 20kHz |
| Total Harmonic Distortion |
0.03% |
| Intermodulation Distortion |
0.03% Maximum |
Signal-to-Noise Ratio
| High-Level Inputs |
97dB A-Weighted Below Rated Output |
| Moving Magnet Phono |
80dB A-Weighted Below 5mV Input |
Input Sensitivity
| Balanced High-Level Input |
600mV for Rated Output |
| Unbalanced High-Level Input |
300mV for Rated Output |
| Moving Magnet Phono Input |
3.0mV for Rated Output |
| Maximum Balanced Input Signal |
8V |
| Maximum Unbalanced Input Signal |
4V |
| Maximum Phono Input Signal |
40mV |
Input Impedance
| Balanced Input Impedance |
20kΩ |
| Unbalanced Input Impedance |
20kΩ |
| Moving Magnet Phono Impedance |
47kΩ |
| Moving Magnet Phono Capacitance |
50pF |
Analogue Inputs
| Total Analogue Inputs |
4 |
| Balanced Input |
1 |
| Unbalanced Inputs |
2 |
| Moving Magnet Phono Input |
1 |
| Moving Coil Phono Input |
No |
| Input Naming |
Yes – User Assignable |
| Input Level Matching |
Yes |
Moving Magnet Phono Stage
| Built-In Phono Preamplifier |
Yes |
| Cartridge Type |
Moving Magnet (MM) |
| MM Input Sensitivity |
3.0mV |
| MM Input Impedance |
47kΩ |
| MM Input Capacitance |
50pF |
| MM Signal-to-Noise Ratio |
80dB |
| Moving Coil Support |
No Direct MC Input |
| External Phono Stage Required for Compatible MM Turntable |
No |
Digital Connectivity
| Internal DAC |
No |
| Digital Coaxial Input |
No |
| Digital Optical Input |
No |
| USB Audio Input |
No |
| MCT Input |
No |
| HDMI ARC |
No |
| Upgradeable Digital Audio Module |
No |
| Design |
All Analogue |
Subwoofer Output
| Subwoofer Output |
1 × Mono |
| Output Type |
Unbalanced |
| Output Frequency Range |
Full Range |
| Rated Output |
1.7V |
| Maximum Output |
6V |
| Output Impedance |
200Ω |
| Powered Subwoofer Compatible |
Yes |
Headphone Amplifier
| Headphone Output |
1 × 1/4" / 6.35mm |
| Technology |
McIntosh High Drive |
| Supported Headphone Impedance |
20Ω – 600Ω |
| Built-In Headphone Amplifier |
Yes |
| External Headphone Amplifier Required |
No for Compatible Headphones |
Tone Controls
| Bass Control |
±10dB |
| Bass Frequency |
70Hz |
| Bass Adjustment Steps |
1dB |
| Treble Control |
±10dB |
| Treble Frequency |
10kHz |
| Treble Adjustment Steps |
1dB |
| Tone Bypass |
Yes |
| Balance Adjustment |
Yes |
Power Guard®
| Power Guard® |
Yes |
| Function |
Output Signal Monitoring / Clipping Protection |
| Protection Objective |
Helps Prevent Harsh Clipping & Potential Speaker Damage |
| Maximum THD with Power Guard Active |
Less Than 2% with up to 16dB Overdrive at 1kHz |
| Visual Indication |
Affected Channel Vacuum Tubes Flash Amber |
Sentry Monitor™
| Sentry Monitor™ |
Yes |
| Function |
Output Stage Protection |
| Protection |
Monitors Potentially Unsafe Operating Conditions |
| Automatic Operation |
Yes |
Damping Factor
| Damping Factor – 8Ω |
Greater Than 200 |
| Damping Factor – 4Ω |
Greater Than 100 |
| Speaker Output Loads |
4Ω / 8Ω |
Speaker Connections
| Speaker Outputs |
2 Channels |
| Speaker Binding Posts |
Gold-Plated |
| Output Load |
4Ω / 8Ω |
| Stereo Speaker System |
Yes |
| External Power Amplifier Required |
No |
Control & Operation
| OLED Display |
Yes |
| Remote Control |
Included |
| Input Selection |
Front Panel / Remote |
| Bass Adjustment |
Front Panel / Remote |
| Treble Adjustment |
Front Panel / Remote |
| Tone Bypass |
Yes |
| Balance Control |
Yes |
| Input Offset / Level Match |
Yes |
| User-Assignable Input Names |
Yes |
System Control Connectivity
| Power Control Output |
1 |
| Power Control Voltage |
12V DC |
| Power Control Current |
25mA |
| Rear Panel Data Port |
1 |
| RS232 |
No |
| IR Sensor Input |
No |
| Home Theater PassThru |
No |
Chassis & Construction
| Chassis |
Dual-Layer |
| Chassis Finish |
Polished Stainless Steel |
| Heatsinks |
McIntosh Monogrammed Heatsinks™ |
| Side Badges |
Die-Cast Aluminium McIntosh Name Badges |
| Tube Protection |
Protective Cages |
| Design Inspiration |
McIntosh MC275 Vacuum Tube Amplifier |
| Output Meters |
No |
Power Requirements
| AC Power |
Factory Configured According to Market Voltage |
| Supported Factory Versions |
100V / 110V / 120V / 220V / 230V / 240V AC |
| AC Frequency |
50/60Hz |
| Standby Consumption |
Less Than 0.5W |
| Field Voltage Conversion |
Not Supported |
Dimensions & Weight
| Width |
12" / 30.5cm |
| Height |
7-5/8" / 19.4cm Including Feet |
| Chassis Depth |
16-1/2" / 41.9cm |
| Overall Installation Depth |
18" / 45.7cm Including Cables |
| Net Weight |
28lb / 12.7kg |
| Shipping Weight |
37lb / 16.8kg |
General Specifications
| Brand |
McIntosh |
| Model |
MA252 |
| Product Category |
2-Channel Hybrid Integrated Amplifier |
| Architecture |
Vacuum-Tube Preamplifier + Solid-State Power Amplifier |
| Vacuum Tubes |
2 × 12AX7A + 2 × 12AT7 |
| Output Power – 8Ω |
100W × 2 |
| Output Power – 4Ω |
160W × 2 |
| Analogue Inputs |
2 × Unbalanced + 1 × Balanced + 1 × MM Phono |
| Subwoofer Output |
1 × Full-Range Mono |
| Headphone Output |
1 × 6.35mm High Drive |
| Internal DAC |
No |
| Digital Inputs |
No |
| Power Guard® |
Yes |
| Sentry Monitor™ |
Yes |
| Monogrammed Heatsinks™ |
Yes |
| Dimensions |
30.5 × 19.4 × 41.9cm (W × H × D) |
| Weight |
12.7kg |
System Integration
The McIntosh MA252 can serve as the central amplifier in a high-performance 2-channel analogue Hi-Fi system. Passive loudspeakers connect directly to its speaker outputs, with the amplifier providing 100 watts per channel into 8-ohm speakers or 160 watts per channel into 4-ohm speakers. A turntable fitted with a compatible Moving Magnet cartridge can connect directly to the dedicated MM phono input without requiring an external phono preamplifier. Line-level sources such as a CD player, DAC, network streamer or tuner can connect through the balanced or unbalanced analogue inputs. Because the MA252 does not include a DAC, digital-only sources require an external DAC or source component with analogue outputs. A powered subwoofer can be connected to the full-range mono subwoofer output, while compatible headphones can be connected directly to the built-in High Drive headphone amplifier.
