A pair of 12AT7 and 12BH7A dual triode vacuum tubes power the compact MHA200. The 12AT7 vacuum tubes amplify the incoming audio signal while the 12BH7A tubes provide the power to drive the output to your headphones with low distortion. The MHA200 uses a pair of our Unity Coupled Circuit output transformers to deliver pristine audio to your ears. Our Unity Coupled Circuit is the same technology McIntosh was founded on in 1949 and is still used in our vaunted full-size home audio vacuum tube amplifiers such as the timeless MC275 and the more recent MC1502. Indeed, the MHA200 shares many physical design traits with the aforementioned vacuum tube amplifiers.
A wide assortment of connectivity options come on the MHA200. For attaching your headphones, there are 3 options: a pair of 3-pin balanced XLR connectors for dedicated Left and Right balanced output; a 4-pin balanced XLR connector for balanced stereo output; and a 1/4″ stereo headphone jack.
For connecting the MHA200 to your home music system’s source components, it has 1 set each of both balanced and unbalanced inputs. Thanks to the MHA200’s small size of just 6-1/8″ (15.6cm) wide x 9-1/8″ (23.2cm) deep and its balanced inputs, it can be placed close to your listening position for ease use, with long balanced audio cables connecting it to your audio system without fear of signal loss.
The MHA200 takes advantage of unique McIntosh technologies to create the best possible personal listening experience. The Unity Coupled Circuit transformers have been adapted to produce 4 headphone impedance ranges of 32 – 100, 100 – 250, 250 – 600, and 600 – 1,000 Ohms at 500mW so that virtually every headphone can receive legendary McIntosh sound quality and performance.
We custom designed and manufactured the output transformers to match the tube amplifier section to the headphone output section in order to ensure maximum power transfer for various headphone loads. Instead of having to adapt to the impedance of the headphones with voltage gain in the input stage, the Unity Coupled Circuit output transformers’ secondary windings ensure the full power of the MHA200 is available regardless of the impedance of your headphones. A custom, high-performance, and highly efficient toroidal power transformer with low mechanical hum and a low magnetic field, which helps reduce electrical noise, provides clean power to the amplifier.
You can select the best impedance range for your headphones via the LOAD knob. The VOLUME knob allows the MHA200 to be connected directly to music sources that only have a fixed volume output without needing a preamplifier for volume control. Conversely, if you’re using a component with variable volume output, then the VOLUME knob should be set to the center Unity Gain point and the volume controlled by the variable output component.