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In short, this amplifier sounds beautiful yet not too pretty. It preserves most the original tone colors, perhaps not as ultra-precisely as the Trafomatic and different also from my Luxman M-800A. The Nagra isn't the grand master of space or ambient retrieval. It also won’t differentiate as well as the above amps. But that’s likely deliberate. How I hear it, Nagra wanted to present the most possible tone whilst maintaining proper focus. And that they have achieved 100%.


There are some elements which even the best 300B amps can’t swing on conventional speakers. The first is bass. Here the Nagra offers an extended strong foundation with a bit of warmth. Although the very low end isn’t as controlled as my Luxman, it is still objectively good. Higher up, the bass becomes very good. Thus the MSA was fabulous on both the potent bass from Voo Voo's XX as well as Joe Pass’ guitar. In the upper part of the range where cymbals or vibraphone live—the latter for example on the Milt Jackson Quartet—things seemed slightly laid back and a bit darker.


Yet I'm not absolutely certain. On specific high-quality recordings like Haden's The Private Collection, especially the second disc with the Webster concert from the University in St. Louis, things didn't sound laid back at all. For confirmation, I paid special attention to tape hiss on a few more recordings. Naturally nobody in their right mind listens for background noise over music but for this purpose, judging master-tape induced noise is as handy a tool as white noise. The Nagra just limited this background noise a bit to indicate a minor modification in the upper band. This wasn’t a selective notch or peak but rather, a gentle slope over a broader range. It becomes unnoticeable on high-quality recordings and avoids impressions of darkness or limitations because the vocal range on a whole is very open and strong.


It’s worth focusing on this band as it does introduce some limitations. While the MSA offers 60 watts into 8 Ω, it doesn’t possess the same drive as my 60wpc Luxman. This suggests that size does matter. At high levels, the Nagra compresses just a bit as on Wojtek Waglewski’s voice on XX. This is a great recording for instruments but very poor on vocals likely due to some recorded compression. Warm amplifiers cover that up a little because they average out the sound on all recordings. Because the Nagra is no classic warm amp, it presents such mastering weaknesses precisely. If we turn up the volume, the Nagra will thus emphasize such flaws. Most likely it won’t be a big issue because it didn't happen in my 30sqm room at standard volumes. If you have a larger room and difficult loads however, I suggest you consider two MSAs in mono mode.


MSA without preamp
: The above comments included my Ayon Polaris II preamplifier with AC Regenerator power supply. Nagra offers their CDC player with integrated preamp so you can always experiment with a CD + amp combo to save money. By coincidence, my new Ancient Audio Lektor Air also sports a built-in (tube) linestage so going CD direct would become an obvious experiment. Surprisingly, withdrawing the amazing 50.000zl+ Ayon preamp changed little overall. While there were changes, they were so small as to render value comparisons irrelevant. By a tiny margin, the overall sonic scale shrunk. The first soundstage layer wasn’t quite as palpable and the bass wasn’t as energetic and less extended. But there also was an improvement in soundstage depth. Where it had been good before, now it was very good. Transparency and resolution were similar (bravo to Ayon). I was really impressed by so small a degree of change. A more distinctive sounding preamp—perhaps Nagra’s own PL-P—should affect greater differences. Given my CD-direct results, I’m certain that a combination of MSA with a CD player with integral line stage like Nagra’s or Ancient Audio’s makes very good sense to perhaps postpone thinking about a preamp.


Summary
: Nagra’s MSA is a very interesting device. With controlled warmth, it makes big transistor sound with vacuum tube traits from a tiny package. It’s important to state that this isn’t a hybrid concept to mix certain qualities. One can tell that everything here has purpose and was intentioned by the designers. Every feature and aspect complements everything else. The MSA amplifier thus has a clear agenda and that's why listening to it becomes so pleasant. Unlike other warm amps, this one might not be the favorite of electronica fans. I believe that Nagra's overriding concern for each sound and its tone reduced some dynamics and shrill edge which are essential for music like Diorama's. Depeche Mode and older albums like Abroken Frame sounded better but their sonic tangibility could still be improved.


Jazz and classic music were remarkable however. If you have a chance, listen for example to the new Linn Records releases of Mozart Symphonies or the fantastic J.S. Bach Goldberg Variations with Matthews Halls on harpsichord. With its brilliant combination of craftsmanship, great looks, a famous brand name and remarkable sound particularly with smaller ensembles, you then might find it difficult to resist this petite Swiss beauty.


Description:
Nagra’s MSA is a stereo amplifier that can be switched to mono. It ingeniously marries Swiss precision with small dimensions. The aluminum case is crowned with a massive heat sink and the front is adorned with the famous Nagra modulometer and power-on selector. The latter switches from off to standby to auto (signal-sensing) to mute to on. The back panel sports two pairs of quality gold-plated WBT 0763 posts and a pair of XLR inputs. Yes, there’s only a balanced input since the circuit is fully balanced. Fortunately you can use the included Neutrik RCA-XLR adapters.


A bridge selector switch on the rear allows parallel bridging to double output current as well as power. A small toggle switches between bridge, normal and bi-amp modes. There are also two small switches to change input sensitivity between 1 and 2V. Finally there’s the IEC power inlet and a mechanical on/off switch.


The compact dimensions were enabled by an innovative power supply. Although the main element is a large shielded power toroidal transformer placed on a separate support, the controller chips (one per channel) are key tooo. There's a specialized Linear Technology LT1248 power factor controller chip in charge of the entire power supply. It is part of the PFC power factor corrector solution first championed in the year 2000 MPA. This circuit is placed between transformer and power supply to generate a correct power sine wave - a sort of on-board power conditioner. This means more surface-mount parts and only two mid-size filtering caps. Here you’ll also find the inductive parts, cored coils and many large polypropylene Wima capacitors.


The actual amplification circuit is amazingly simple, its signal path very short. It is based on a pair of Mosfet transistors working in class AB. All circuit boards are high quality with gold-plated traces. The input socket is direct-soldered to the small shielded input PCB and input sensitivity is set via bridge resistors.


The MSA doesn’t use conventional footers but four plastic discs. Nagra simply encourages users to experiment with different feet, spikes and so forth. That explains the presence of four pre-drilled holes which for example fit Finite Elemente’s Ceraballs. In my opinion it is much more reasonable however to purchase Nagra's VFS vibration free support which, though first designed for their phonostage, also works very well with their PL-P preamplifier and now MSA amp. It is so universal because all these Nagra models share the same footprint. The VFS consists of two 7mm aluminum plates decoupled with alpha-GEL pellets. Colored differently, these pellets are weight-rated to eliminate specific vibrational energies in both the vertical and horizontal axes. The VFS ships with three spikes or feet to be screwed into the bottom of the Nagra unit you wish to support. Machined from ARCAp, a non-magnetic non-ferrous copper-nickel-zinc alloy with Delrin resin tips, these footers also really dress up this support system.


Technical data according to manufacturer:

Power: 2 x 60 W RMS/8 Ω (normal mode selected)
Input sensitivity: 1 or 2 V (selectable)
Bandwidth: (+0/-3 dB): 10 Hz-70 kHz
S/N: 104 dB
THD+N: < 0,09 %/100 W
Size: 280 x 230 x 118 mm
Weight: 9.6 kg


opinia @ highfidelity.pl

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