Tube for the fine, solid state for pure power, combined in a single power amplifier, which should therefore be an ideal solution for bi-amping, this is how McIntosh Laboratory Inc. describes the new McIntosh MC901 Dual Mono Amplifier, which thus combines two amplifier concepts.
The US-American high-end hi-fi forge McIntosh Laboratory Inc. is probably best known for its outstanding amplifier systems, because in this field the company can point to a multitude of solutions with the most diverse concepts. The company is quite open about the question of which technology is supposedly the better one, but this question is not really a decision to be made, as the company offers products for all “faiths”. But the fact that one goes so far as to combine classic tube and solid state in a single power amplifier is again new and very exciting.
So the new McIntosh MC901 Dual Mono Amplifier presents itself as the usual powerful solution, combining tube technology and solid state in a new way, in the form of an amplifier designed for bi-amping, with tube for the upper and middle range and solid state for the bass. The tube section alone is not stingy with power, it delivers a full 300 watts. But Solid State really gets down to business, with the new McIntosh MC901 Dual Mono Amplifier an additional 600 watts are available.
The company speaks of “a truly one-of-a-kind home audio amplifier” and is probably right, because the concept used in the new McIntosh MC901 Dual Mono Amplifier is indeed at least exceptional. An amplifier that combines two amplifier concepts in order to drive a loudspeaker in the best possible way and get the best out of it is not unusual, but this is usually found in the form of a pre- and power amplifier combination. Tube is then used in the preamplifier, solid state in the power amplifier. The McIntosh MC901 Dual Mono Amplifier is a pure power amplifier, however, and relies on separation across the frequency range.
According to McIntosh Laboratory Inc. tubes would not function optimally when it comes to amplifying low frequencies, so the new McIntosh MC901 Dual Mono Amplifier does not include this, and transfers this task to a much more suitable solid state amplifier section. In this way, the two amplifier technologies should work in absolute synergy and guarantee an optimal result.
McIntosh Laboratory Inc. has been developing and manufacturing tube amplifiers since the company was founded in 1949, Solid State since the 1960s. All the expertise gathered over the decades has gone into the new McIntosh MC901 Dual Mono Amplifier.
The new McIntosh MC901 Dual Mono Amplifier is designed as a so-called Quad Balanced Dual Mono Amplifier.
The tube section of the McIntosh MC901 Dual Mono Amplifier relies on no fewer than eight KT88s in the output stage, to which four 12AT7s and two 12AX7As are connected. The McIntosh Unity Coupled Circuit Output Transfomer, known since the first systems in 1949, is used here to achieve the full power of 300 watts, regardless of the impedance of the loudspeaker systems of 2, 4 or 8 ohms.
The solid state section of the McIntosh MC901 Dual Mono Amplifier uses a similar concept to deliver full power at impedances of 2, 4 and 8 ohms, known as McIntosh Autoformer Technology.
Each amplifier stage of the McIntosh MC901 Dual Mono Amplifier has a separate power supply to ensure optimal isolation.
Of course, a concept like this requires an additional component, namely a crossover network. After all, the new McIntosh MC901 Dual Mono Amplifier is designed to divide the frequency ranges for the division of labour between tube and transistor directly in the amplifier. This is designed in such a way that the crossover frequency can be adjusted by the user, and the level for the two power amplifiers can also be fine-tuned in the range from -6 dB to +3 dB. Of course, the McIntosh MC901 Dual Mono Amplifier also offers the possibility of a bypass.
It goes without saying that the new McIntosh MC901 Dual Mono Amplifier also uses all the manufacturer’s known technologies. First and foremost, McIntosh Power Guard is used, although McIntosh Power Guard Screen Grid Sensor (SGS) is also used here, which is dedicated solely to the tube section. The McIntosh Sentry Monitor is just as important as the traditional design of the cooling elements in the form of the McIntosh logo, called McIntosh Monogrammed Heatsinks. For the connections, gold-plated solid RCA speaker binding posts are used and the front is adorned with the familiar blue illuminated VU meter, although a DualView meter is used here since the signal from two power amplifiers must be visualized.
No one will be surprised that the new McIntosh MC901 Dual Mono Amplifier is not a lightweight. It weighs an impressive 81.6 kg and measures 44.5 cm in width, 33.7 cm in height and 74.9 cm in depth.
The McIntosh MC901 Dual Mono Amplifier should already be available in specialist shops these days. The recommended retail price is € 22.450,-.
Getting to the point
The new McIntosh MC901 Dual Mono Amplifier presents itself as the usual powerful solution, combining tube technology and solid state in a new way, in the form of an amplifier designed primarily for bi-amping, with tube for the upper and middle, solid state for the bass. The tube section alone is not stingy with power, it delivers a full 300 watts. But Solid State really gets down to business, with the new McIntosh MC901 Dual Mono Amplifier an additional 600 watts are available.