Norma Audio Revo IPA-140
The history of Norma Audio began in 1987 in Cremona - the hometown of famous composers, such as Ponchielli and Monteverdi, and great violin masters - Stradivari, Amati, and Guarneri. It was a man with an equally Italian-sounding name - Enrico Rossi - who created the apparatus on which you can listen to such wonderful music in the comfort of your living room. The first device manufactured under the Norma Audio brand was the NS 123 amplifier. It was not a spectacular commercial success, but nobody expected that. A completely new chapter in the company's history began when it was acquired by Opal Electronics, a manufacturer of electronic measuring devices. In 1991, Norma's owner started a research project to understand how audio equipment can degrade sound and how this can be avoided. Seven years later, he found what he was looking for. It was certainly not one brilliant solution but rather a collection of rules and general guidelines. Unlike manufacturers who have built their reputation on a particular technical solution, Norma doesn't base its entire business on a single patent. But if you would like to know what you can expect from this gear, Enrico Rossi makes it clear - the sound should be natural, dynamic, and succinct with a very realistic midrange.
As a well-trained listener who has regularly attended classical music concerts since childhood, the Italian designer understood quite quickly how different amplifiers sound and how their parameters translate into what comes out of the speakers. One can guess that he spent a long time analyzing how the character of the sound of a given system is affected by, for example, distortion or phase. In the course of his work, Enrico Rossi investigated how circuit topology, component quality, mechanical design, and power supply structure affect one another and how they can be combined to achieve the best possible sound quality. He discovered that for an amplifier to be able to deliver current instantly, a much more efficient power supply is needed than is commonly believed, and that to achieve neutral, convincing sound, wide frequency response is also required, far beyond the limits that most experts consider to be the end of the human hearing organ's capabilities. A wideband amplifier places high demands on the designer in terms of electronic circuit design and its power supply and grounding. 20 kHz? Nope. In Enrico Rossi's devices, the frequency response reaches 2 MHz! At first, I couldn't believe it, but when the frequency response of the Revo IPA-140 integrated amplifier starts at 0.1 Hz and goes all the way up to 2 MHz (-3 dB). And it's not a "digital" circuit or an exotic device based on computer graphics cards, but a completely normal analog amplifier. Or is it?
Design and functionality
Revo IPA-140 is the flagship integrated amplifier in Norma Audio's catalog. The current generation is the fifth, but the manufacturer doesn't boast about that fact, nor uses any new designations like "mkV", claiming that it is better to introduce minor improvements on an ongoing basis than to introduce a "new model" every two years. As its symbol indicates, the amplifier delivers 140 W per channel into 8 ohms and doubles that power into 4 ohms. It's a conventional class AB design with twelve MOSFET transistors, six in each channel. What seems slightly unusual for an Italian manufacturer of audiophile equipment, the appearance seems to play a secondary role in the design of the electronics. In my opinion, Revo IPA-140 is a beautiful amplifier, which results not only from the shape of its enclosure, but most of all from high-quality materials, very precise metalwork, and clever ideas such as hiding the heat sinks in the space between the base and the cover.
The entire housing is made of brushed aluminum. Customers can choose between two color versions - black and silver, where the inner skeleton, the heatsinks visible on the sides, and the rear panel are always black. The silver version changes the color of the front panel and twin plates, one of which is the base and the other - the cover of the amplifier. Interestingly, the black version is a little more expensive. The front panel is decorated with a relatively large volume control knob, protruding strongly to the front. The same finish is applied to the button located on its right side, which serves as a standby mode switch and an input selector. On the left, we have an infrared receiver for the remote control, and as far as the design is concerned, that is basically it. The aesthetes are probably not going to love the silver heads of screws holding the cover in place. Surely it could have been done differently, for example, by mounting this element from the bottom with longer screws. However, it seems to me that the manufacturer anticipated something quite obvious. Because the cover slightly protrudes beyond the heatsinks, there are two places where you can grab and lift the Revo IPA-140. And it's pretty heavy - 25 kg, to be exact.
Although we'll get to the description of the Revo IPA-140's interior later, I'm confident that experienced audiophiles will see the true beauty of this unit the moment they lift its cover. This amplifier is one of the most elegant examples of a dual-mono circuit I have seen in my life. The silver knob marks the axis of symmetry, and the "mirror" reflects everything, including the toroidal transformers. Truly wonderful! Perfect symmetry can also be seen at the back. The top part of the rear panel contains a total of eight RCA sockets, four for each channel. Their descriptions are a bit strange - while "IN1 Phono" or "IN4 Line" don't raise any doubts, "IN3 Out" can cause consternation. So what is it after all - input or output? Before connecting cables, it's certainly worth having a look at the manual. Owners of sources with balanced outputs will have an easier task, as they will immediately use XLRs. However, the manufacturer does not encourage us to use the balanced input, and our listening session confirmed that switching from RCA to XLR cables doesn't bring any spectacular improvement in sound quality. The Italians are probably not fans of bi-wiring either, as there are single speaker terminals mounted on the sides. In the center of the rear panel, we find a power socket with an on/off switch and a fuse, a USB type B input, and a ground terminal for the turntable. The last two of these items are optional. The DAC module for the Revo IPA-140 is simply called USB-2. It's based on the AKM 4391 and costs $800. The PH-2 phono stage is even more enjoyable. It has the form of two identical boards that are mounted, as I understand, behind each of the sockets described as "IN1 Phono". The module works with MM and MC cartridges, and its price is $500. I must admit that I have seen various "cards" with a phono preamp section but using two separate modules is quite something. Perhaps there is nothing strange in that as Enrico Rossi supposedly collected about thirty thousand vinyl records.
In the box, apart from the amplifier, there are only two important things - a thick manual and remote control in the form of an interesting metal bar. It's a system controller, and therefore, there are too many buttons to operate the integrated amplifier, but if you're planning on buying Norma Audio's source as well, it will be just fine. I'm not too fond of the tiny but strongly protruding buttons, but the overall form of the remote control and the fact that it even has rubber feet, so it does not slip and does not scratch the table surface deserve recognition. The user manual doesn't look particularly impressive at first glance, but I heard a strange rattling sound when I took it out. Surprisingly, it wasn't a sachet with moisture-absorbing granules but a ziplock bag with tiny spare parts like fuses, screws, and plastic caps. The manufacturer clipped it to the back cover of the manual, along with a description of each fuse. I must admit that I like it very much, and if I had bought the amplifier and not just borrowed it for the review, I would have liked it even more. You don't buy such equipment for one or two years. Its life cycle is much longer, or at least it should be. After a few years, such a machine may end up in the hands of another audiophile (sometimes a descendant of the purchaser, accustomed to good sound since childhood), then another, and so on. Lovers of hi-fi equipment usually take good care of their toys. It can be assumed, however, that after twenty years, such equipment will have to get serviced or renewed. Speakers usually have a longer life, but with an amplifier, maintenance work usually includes replacing capacitors, cleaning or reconditioning the volume control, replacing the heat conductor between the transistors and heatsinks, and adjusting the bias. Most internal components can be replaced by a good technician, but some small details are hard to match. Fuses can be found at any electronic store, but try to remove a screw from some hi-end amplifier and buy an identical one somewhere. Believe it or not, as I have been professionally reviewing stereo equipment for almost eighteen years, this is the first time I have seen a bag with spare parts included in the set. And it wasn't done by reasonable Scandinavians, not by practical Germans, but in an amplifier that smells of pizza and pasta, built by Enrico Rossi in Cremona. It is time to check how this Italian stallion will perform in the listening test.
It's no secret that Italians like to go crazy. First of all, with the design, but sometimes also with the sound. You can get the impression that they cannot create a device that doesn't strike the eye or sound characteristic. Unison Research loves tubes, so its amplifiers sound warm. I like it, but I know they aren't aimed at 100% transparency. Synthesis is quite similar, but we are dealing with even more frivolity in design and strange ideas, such as creating a hybrid with a small chip in the preamplifier section and a tube power amplifier. Pathos, Gold Note, Monrio, Riviera Audio Laboratories, Aqua - these are all devices with plenty of character. Of course, many audiophiles salivate at the sight of these amplifiers, but even if you can also fall in love with their sound, some people are afraid to buy something that crazy and decide on equipment that looks and sounds, let's say, more normal. They will choose Hegel, NAD, Marantz, maybe even Naim. Why? Because it might be time to change speakers soon, and a neutral amplifier is more straightforward when matching speakers to it. Because our musical preferences change over time and a good stereo must cope with any material. Because in a few years, we will probably be able to replace such amplifier with something better, and it's much easier to sell a device with an even and relatively neutral sound than one that has its approach to music and is not ashamed of it. Of the Italian manufacturers who focus on a completely different sound, without excessive warming, without coloration, going more in dynamics and transparency, I can think of two big brands - Audio Analogue and Audia. Both brands offer very appealing equipment, but if we want to taste a truly high-end sound, we must forget about their cheapest amplifiers and prepare ourselves for a much more considerable expense.
And where is Norma Audio in all that? Well, it's where not many Italian audiophile manufacturers have gone before - right next to Krell, Mark Levinson, Parasound, ModWright, and other brands famous for manufacturing extremely powerful amplifiers that can grab even extremely difficult to drive speakers by the throat and on the other hand - deliver an even, natural, well arranged, rich, and convincing sound, not only in terms of dynamics. To put it briefly, after just a few minutes of listening, I knew that I was dealing with an outstanding design, and during a more extended listening session, different variants of "ohs" and "ahhs," sometimes even dressed in censorious words, were uttered frequently. The Italian amp immediately took complete control over the situation. It did not care what speakers, source, and cables I used. Revo IPA-140 started with such charisma and confidence that changing the speakers probably wouldn't make much difference. So if you long for amplifiers that were not yet extremely expensive but able to rock like powerful monoblocks and at the same time sound ordinary and natural enough not to seem overcomplicated, I bring you good news - such devices are still manufactured.
This amplifier will not bet on any one thing, offering a holistic approach to sound. However, I don't think it sounds boring. The bass is deep and resilient. The midrange is neutral, detailed, and delicately, but only slightly thickened (just enough to get the impression that the vocalists are robots and not flesh and blood people). High frequencies are selective and nicely polished. On top of that, we have a vast reserve of power and something that will be the absolute icing on the cake - holographic soundstage, confirming all "stereotypes" about full dual-mono amplifiers for many listeners. Enrico Rossi resisted the temptation to create another distinctive device. He went a bit crazy with the design, but not as crazy as some of his compatriots. From the outside, this amp is not so interestingly shaped as beautifully made - we pay more attention to individual components and the way they are put together than the form of the device itself. I also hear only one element that bears traces of its coloration in terms of sound - the midrange. Anyway, maybe there is nothing strange in that because Enrico Rossi emphasizes that, in his opinion, it's the most critical part of the frequency range. In music, vocals are the most important. Let's say that I agree with that. Everything else is, well, normal. And wonderfully easy to listen to. That is why the Revo IPA-140 will appeal to both the experienced audiophiles and the beginners who are not accustomed to using specialized vocabulary and don't really know what to pay attention to but trust their ears. They don't associate dynamics with large transformers, but they can often unerringly point out which equipment sounds well. I am convinced that the Revo IPA-140 is an amplifier so successful that it will impress even novice listeners. And I consider that a high compliment.
Build quality and technical parameters
Norma Audio Revo IPA-140 is an integrated amplifier delivering 140 W per channel (8 Ω). Lifting the aluminum cover reveals that we are dealing with a dual-mono system, although some components, including two substantial toroidal transformers, are hidden in additional cases made of black anodized aluminum. If we don't count the volume control, a power jack, optional USB input, and grounding terminal for the turntable, what we have here are, in fact, two monoblocks with one front panel. Interestingly, we won't see a single wire inside. The power amplifier section is placed at the very top. The circuit uses six MOSFET transistors for each channel. They are screwed to aluminum blocks, which are mounted together with the entire board. Once in place, these blocks fit tightly onto the actual heat sinks, clearly visible from the outside. A few centimeters below the power amplifier section, we see a module of the same size with input circuits and the power supply. I could not get to that part of the amplifier. Still, the manufacturer shared some very detailed pictures with us, where you can see densely packed red Itelcond capacitors, also used by Pathos and Unison Research. As far as the quality of components is concerned, there are no weak points here. The parameters are equally satisfying. The frequency response certainly stands out against the competition, not only at this price. 0.1 Hz - 2 MHz! Enrico Rossi explains that simpler circuits are not necessarily better than more complex ones. That's why Norma Audio components are very complex. Their frequency response extends well beyond 20 Hz - 20 kHz, not at all to please humpback whales and bats, but to improve the overall speed of the amplifier and immediately deliver the right amount of current to the speakers. An amplifier constructed in this way has other advantages as well. Because the circuit operates linearly up to very high frequencies, it remains insensitive to intermodulation effects and interference from, for example, the mains supply.
Audiovector QR5, DALI Menuet SE, AudioSolutions Figaro B, ELAC Debut Reference 62, Auralic Vega G1, Unison Research Triode 25, Clearaudio Concept, Cambridge Audio CP2, Cardas Clear Reflection, Albedo Geo, Enerr One 6S DCB, Enerr Transcenda Ultra, Enerr Transcenda Ultimate, Custom Design RS 202, Norstone Esse.
The Revo IPA-140 is a wonderful device. Beautiful on the outside, beautiful on the inside, and as powerful as an American power amplifier weighing forty kilograms. Most importantly for an audiophile, delivering natural, dynamic, transparent sound with powerful bass and rich midrange, holographic space, and sublime treble. If someone asked me to put together the best possible stereo system for them, where speakers, source, cables, and accessories can be as big and expensive as they need to be, but at the center of it all must be an integrated amplifier costing no more than $10000, I would call the nearest Norma dealer and order the Revo IPA-140, confident that the mission would be accomplished. Actually, the only regret I have is that I received a version without the DAC and phono stage for the review. Fortunately, nothing is lost because Norma Audio offers several stand-alone digital sources that are said to be not even slightly inferior to the amplifiers in terms of craft and sound quality. I think I'll have to take one of them in for a review and see for myself.
Output power: 2 x 140 W/8 Ω, 2 x 280 W/4 Ω
Analog inputs: 4 x RCA, 1 x XLR
Digital inputs: 1 x USB (optional)
Input impedance: 10 kΩ
Gain: 34 dB
Output current: 36 A continuous, 150 A peak (per channel)
Frequency response: 0,1 Hz - 2 MHz (-3 dB)
Dimensions (H/W/D): 12,5/43/43 cm
Weight: 25 kg
Manufacturer: Norma Audio