An aesthetic that leaves no one indifferent due to its calculated combination of luxury and constructive sophistication constitutes the letter of presentation of one of McIntosh’s most striking – and powerful – proposals regarding stereo integrated amplifiers: the MA352. A product that, like other achievements of the legendary New York firm, demonstrates extensive mastery of the different existing engineering solutions for the processing of audio signals.
In this case, the chosen combination has been tube preamplification and transistor power amplificationthe latter with a topology different from that usually used by McIntosh, in order to expand the range of available options for the lover of absolute sound who seeks guaranteed excellence in all aspects. The result in this case is a superb bass control that merges with some warm middle and upper zones and precise at the same time. In short, an integrated electronic that deserves to be among the elite in its own right.
Valves and transistors in integrated amplifiers: guaranteed seduction
We have already spoken on numerous occasions about the advantages that in terms of sound the vacuum valves and the devices solid state (bipolar transistors, FET’s and MOSFET’s). Advantages… and also disadvantages that depend on both the aforementioned devices and the passive components that accompany them and the design of the circuitry of which they are part. Hence, depending on the preferences of the engineer responsible for the conception of a certain product, the type of sound sought and the available budget are multiple possibilities to consider.
Without a doubt, integrated amplifiers are the type of product that most lends itself to combine valves and transistors, being able to find both models with vacuum devices in the input/preamplification section and solid state in the output/power amplification section, as well as others that opt for the reverse configuration. Still, whatever the topology used, there is a common concept that influences directly in the signal that is sent to the speakers and, therefore, in the sound: the coupling.
To understand this concept, the first thing you need to know is that many audio electronics contain several stages of amplification and consequently several amplifiers. This is because amplification stages are often added when one cannot provide the required amount of amplification.
For example, if a single amplification stage provides a gain of 100 and the desired gain for our product is 1,000, two amplification stages will be necessary: for example, one of 10 and one of 100, one of 20 and one of 50. or one of 24 and one of 40. In any case, there has to be some way for the audio signal enters the amplifier and exits of the same. Well then: the process of transferring energy between circuits is known as coupling and, as expected, there are several solutions to carry it out: direct coupling, RC coupling and transformer coupling.
MA352: valves in preamplification and direct coupling in the output stage
What we have just said leads us directly to the protagonist of this Blog, an impressive and elegant integrated stereo amplifier. one hundred percent analogwith hybrid circuit architecture, and that responds to the name of MA352. An electronic device that combines a preamplification section based on vacuum tubes with a direct-coupled power amplification section that allows it to deliver 200 continuous watts per channel over 8 ohms or 320 continuous watts per channel over 4 ohms. This leads us to ask what is the direct coupling and what advantages it can bring to an audio amplifier, since McIntosh is characterized by using the transformer coupling not only in their tube amplifiers, but also in their solid state ones.
Of all the coupling methods, the direct coupling It is the one that uses the smallest number of circuit elements and consists, as its name suggests, of directly connecting the output of one stage to the input of the next. The direct coupling provides a good frequency response, since frequency-sensitive components (coils and capacitors) are not used, which means that said frequency response will depend only on the amplification device itself. Weak points? In principle, the fact that each successive stage requires a higher voltage implies extra demands in terms of power supply and impedance adaptation, but in the High End field, which is to which the MA352 belongs, such impediments are solved using top quality components as cost is a secondary factor. In this sense, it is important to note that the MA352 includes two of the exclusive Monogrammed Heatsinks heatsinks by McIntosh for maximize thermal stability of the advanced high-current, high-speed response transistors in its output section.
In the area of connectivitywe have a total of 6 entries divided into 2 balanced line, 3 unbalanced line and 1 phono for moving magnet (MM) capsules, to which a exit game unbalanced. To this we must add a 5 band tone control completely analog, one of the versatile high current headphone amplifiers Headphone Crossfeed Director (HXD) from McIntosh, powerful electronic protection – the proven Power Guard and Sentry Monitor systems from the American firm – and two iconic elements of the brand: the treated glass front panel and two elegant analogue vu meters with a blue background.
A listening overflowing with vitality
The power of the MA352 goes a long way when it comes to attacking loudspeakers, so we listened to it in the company of a couple of Sonus Faber Olympica Nova Va turntable Pro-Ject The Classic EVO with moving magnet capsule Ortofon 2M Black LVB 250– and a CD player with network connectivity Primare CD35 Prismthe assembly being wired with 5th Generation Transparent Super. It cannot be denied that the status of the MA352 as 100% analog electronics translates to a sound in which the liquid character and tonal precision (although without excesses of surgical analysis) set the tone at all times, regardless of the musical genre reproduced and the source used.
But what we have just said is not particularly surprising in an electronics of McIntosh origin because, in a way, it constitutes one of the hallmarks of the brand. On the contrary, the use of a very robust and well-tuned transistorized output section results in a Truly powerful bass control and extension that in combination with a genuinely “live” dynamics The result is a punch that borders on the visceral. In this sense, it cannot be denied that the MA352 makes the magnificent Olympica Nova V “fly”, to the point of providing a prodigious realism to the sound scene obtained because it is structured perfectly in the three dimensions of space. Without a doubt, the MA352 is an integrated amplifier that will dazzle lovers of amplified live music, without this quality forcing you to sacrifice delicacy thanks to the impeccable balance between tubes and transistors what he boasts about.