June 2026

World Premiere Review!
Nagra PREAMP II-S Review: Swiss Reference Vacuum Tube Engineering Unveiled
First expert listen to Nagra's tube preamplifier with their eye-candy Modulometer.
Review By Tom Lyle

  This review features Nagra's latest preamplifier, the Preamp II-S. I previously had the opportunity to review two other Nagra products for Enjoy the Music.com. My first experience with their Swiss-made Nagra components came during my 2018 review of the Nagra Classic Preamp. Many audiophiles are aware that Nagra has spent 50 years designing and manufacturing "indestructible, Swiss-engineered, portable, and industry-standard" reel-to-reel tape recorders. Their first model was launched in 1953, and by the late 1950s, these recorders had gained considerable popularity. Nagra began designing high-end audio components in 1997.

In the past, I frequently saw journalists and engineers using Nagra reel-to-reel recorders at music events. These machines were trusted and gave the appearance that they were built to last. Anyone familiar with location recording understands the importance of having reliable, high-quality portable recorders. It's no surprise that music enthusiasts appreciate Nagra's high-end audio gear for its sonic quality, dependability, and distinctive aesthetics.

Modulometer
I appreciate that Nagra designs many of its components, including the Preamp II-S, to evoke the look and feel of its classic reel-to-reel tape recorders. For example, its front-panel Nagra  Modulometer allows users to see left- and right-channel audio levels.

The  Nagra Audio Modulometer is not only distinctive in appearance but also functional; its needle responds rapidly to changes, making it easy to monitor sound levels. The meter's scale is well-marked, allowing users to easily detect slight volume differences between channels and set accurate levels during setup. While I didn't use the  Modulometer daily, it was helpful during setup and troubleshooting. It enabled me to confirm that both channels were receiving a signal and functioning correctly. At times, it helped identify cable issues or signal loss, which I could then address quickly. Plus, it looks cool.

Priorities
Some high-end audio brands share my priorities, and Nagra's latest components particularly resonate with me. Nagra describes its Series II design as prioritizing sound quality while maintaining a compact footprint. I agree that sound quality should be the top priority—even if it necessitates a larger component. However, many will appreciate that the Preamp II-S is only 11 inches wide, making it more practical for contemporary spaces.

Nagra also emphasizes vibration control. A phenolic damping layer under the preamp's aluminum top plate provides added strength, heat resistance, insulation, and chemical resistance.

Vacuum Tubes
The Nagra Preamp II-S utilizes vacuum tubes in its audio circuits. The linestage section includes two 12AX7 (ECC83) tubes to manage the input signal and boost its strength, along with a 12AT7 (ECC82) tube functioning as a buffer to maintain clarity. Nagra states that these tubes are a newer, more durable generation that produces less unwanted noise. The result of these upgraded tubes, according to Nagra, "Is a clear, open sound with detailed imaging and an airy treble."

For those who enjoy swapping tubes—often referred to as "tube rolling"—various brands or versions can be used to modify the character of the sound while keeping the music clean and precise.

Power
The performance of the Nagra Preamp II-S is significantly enhanced by its power supply. As noted in many of my reviews for Enjoy The Music, I place great importance on the power supply in audio components. The Preamp II-S featured an external power supply, which helped minimize interference from one's home's AC power and lowered the noise floor. The unit came with Nagra's Compact PSU, providing clean and stable power. If one already owns a Nagra power supply, such as the Nagra MPS or Classic PSU, one can purchase the Preamp II-S without a power supply, as these models use the same LEMO connector that Nagra has employed since they began manufacturing high-end audio equipment.

On the front panel of the Nagra Preamp II-S, two notable switches stand out. The switch on the bottom right controls the output level. One position sets it to 0 dB, where the preamp adds no additional gain, making the II-S function like a passive preamp. Yet the preamp remains fully active, with a high-impedance input and an exceptionally low impedance output, so it can drive any amplifier. The other position adds +6 dB of gain, which I used for most of the review. The other switch lets the user choose between RCA and XLR outputs on the preamp's rear panel.

The measured noise performance of the Nagra Preamp II-S is exceptional, closely matching that of the Nagra Classic Preamp I reviewed earlier. However, when it comes to enjoying music, measurements take a backseat—the true test is one's ears.

Compared to other preamps, the Nagra Preamp II-S did not produce a black background; instead, it was sonically invisible. This near-total silence often evoked awe and made me trust that this preamp revealed every detail without distraction and enhanced my connection to the music. Combined with its other sonic characteristics (which will be discussed later), the Nagra Preamp II-S competes with much higher-priced preamps. Ultimately, as I listened, I found that breaking down audiophile traits became unnecessary, as the experience was wholly about the music itself.

In my experience, when compared to other top-tier preamps I had at hand, including the Nagra Classic Preamp, the two-chassis Pass Labs XP-22, and the TAD Evolution C1000 preamplifier, the Preamp II-S stands out not only for its nearly complete absence of background noise but also for its ability to retain intricate musical details even at low volumes.

While some high-end preamps maintain a low noise floor but may introduce a slight haze or remain somewhat audible at high-gain settings, the Nagra Preamp II-S delivers an almost uncanny sense of silence. The dynamic range of the Preamp II-S is equally impressive. The dynamic range of the Preamp II-S surpassed that of its competitors, capturing sudden shifts in intensity with precision while avoiding compression or added grain. This remarkable combination of an incredibly low noise measurement and dynamic range made music emerge from silence, enhancing both the musical signal's expressiveness and realism.

System
The system I used for this review was not a state-of-the-art, no-expense-spared setup like the systems in an active audio show display. But I've spent quite a bit of time fine-tuning my setup to achieve an accurate, musical sound that's also revealing enough to expose this Nagra preamplifier's true sonic characteristics.

The review system was in a dedicated, acoustically treated listening room, with two power lines devoted to it that ran directly to our home's circuit box. Not only are there acoustic panels lining the front, rear, side walls, and the ceiling, but there are also shelves filled with LPs lining many of the listening room's walls. The room was painted with Sherwin-Williams "Sky Fall" blue. Psychology Today claims that blue affects people cognitively and emotionally, reducing stress and lowering heart rates, among other benefits.

The system's analog front-end used a Basis Audio Model V turntable with an AC synchronous motor, which allowed me to use an outboard power supply and speed controller. A Lyra Atlas Lambda cartridge was mounted on a Tri-Planar 6 tonearm; its integral cable connected to a Pass Laboratories XP-27 two-chassis phono preamp. The XP-27 then fed the Nagra Preamp II-S's XLR input.

The digital front-end included a computer-based music server and a Simaudio Moon 681 DAC/streamer. The streamer in the 681 used a proprietary app that let me use TIDAL and Qobuz streaming apps, both of which were loaded on my iPhone and iPad. Both TIDAL and Qobuz were also loaded onto the music server, along with many terabytes of FLAC files stored on NAS hard drives hard-wired to the computer, which could either be streamed to the Moon 681 DAC or sent via its USB output. I sometimes used a discontinued but very capable Oppo UDP-203 Blu-ray / universal disc player to spin SACDs and DVD-Audio discs.

All the components, other than the subwoofers and some accessories, were connected to a Stromtank S-2500 battery power supply. This German behemoth removed the audio components from the power grid, therefore bypassing the dirty AC power from our local electric company. The rest, including the subwoofers, had their AC cables connected to a Chang Lightspeed ISO 9300 power conditioner.

The Nagra Preamp II-S fed a pair of Pass Labs X600.8 monoblocks, each with 600 Watts into 8 Ohms. They powered my Raidho TD4.2 reference loudspeakers. Their low frequencies reached down to a very respectable 25 Hz, but I augmented the very lowest bass with a pair of SVS SB16-Ultra subwoofers, which extend down to 16 Hz.

Height
During the height of the CD era, from the 1990s to about the early 2000s, even though new releases were often difficult to come by on vinyl, it was a great time to buy harder-to-find vinyl. Many collectors and others sold their LPs, perhaps seeing them as outdated, while they made the switch to CDs. One thing I would do during this period is log on to eBay and search for Japanese vinyl and other vinyl treasures, where sellers offered their records at what seemed like bargain prices. I often paid more for the postage than the vinyl. That is how I obtained my nearly perfect-sounding Japanese pressing of John Coltrane's album, A Love Supreme.

The copy I acquired was pressed in 1973. This all-analog copy was pressed in 1973, and although there were other Japanese pressings of this album made before and after, this copy is considered by many to be the best Japanese pressing of all. There have been many "audiophile" vinyl reissues of this album since then, but I find no reason to upgrade this fantastic-sounding edition. John Coltrane and his quartet recorded A Love Supreme in one day in December 1964 at Rudy Van Gelder's New Jersey studio. Coltrane led on tenor saxophone and vocals, joined by McCoy Tyner on piano, Jimmy Garrison on bass, and Elvin Jones on drums, gong, and timpani. Released on Impulse Records in 1965, the record stands as both one of Coltrane's best-sellers and, by many, as one of the greatest albums ever recorded, regardless of genre.

The Nagra Preamp II-S preserved the recording's integrity, letting the signal pass without adding its own character. As a result, my speakers delivered a very realistic presentation of this session. While no home system can perfectly replicate a live event, the Preamp II-S helped my reference system reproduce this album with impressive accuracy and realism. I often found myself quickly turning my head to locate sounds that seemed to be coming from elsewhere in the room. If you've ever sat near a tenor saxophone in person, you know it can produce very loud peaks. Even without turning up the volume to as loud as possible, even at a "reasonable" volume, the Preamp II-S allowed Coltrane's sax to move from a whisper to a howl, capturing microdynamics and subtle shifts within a single phrase with ease.

During John Coltrane's stream-of-consciousness solos, his sax became his voice, and his articulation and expressiveness were rendered with an eerie realism. Each measure of music in Coltrane's solos seemed to be a different thought, which could be divided further into sentences made of the notes in each mini-melody he played. I realize some might think I shouldn't discuss John Coltrane's playing on this record more than the traits of the Preamp II-S. But this is one of the greatest compliments I could give a component, where the music becomes what is praised, not the component.

Rock
One of my favorite rock albums is David Bowie's The Rise And Fall Of Ziggy Stardust And The Spiders From Mars. For this review, I streamed the 24-bit/192k version via Qobuz on the Moon 681 streamer, even though I have a few other versions available, both digital and on LP.

Even though the production on this album is credited to both David Bowie and Ken Scott, I suspect that Ken's experience as an engineer made him more responsible for the album's excellent sound quality. During the 1970s, many of David Bowie's albums were produced by either Ken Scott or Bowie's friend Tony Visconti. I believe their styles are similar in that they can sort through the multitude of sounds on a multi-track tape to separate the instruments and voices, the opposite of a wall of sound.

This album features a typical rock lineup: Mick Ronson on guitar and piano, Trevor Bolder on bass, and Mick Woodmansey on drums. Bowie performs vocals, saxophone, and some guitar. Yet, the resulting sound is far from typical. Ken Scott achieves this by combining instruments in new ways, using overdubs, and applying his unique style, almost acting as a member of the band; yet there is never a doubt that it's a Bowie album.

On "Starman," which was intentionally written as a single, Ronson or Bowie entered, playing two 12-string guitars, which were not centered between the speakers, but instead each was panned to a separate channel. The guitars sounded eerily realistic. Mick Ronson's electric guitar sat at the rear of the large soundstage until Bowie's first verse, when both 12-string guitars merged into one channel. This intro took less than a minute, but it could have been the basis of an entire song if written by a lesser songwriter.

David Bowie's voice was solidly placed between the two speakers, seemingly separated from the many instruments and voices, but this might not have had more to do with the transparency of this Nagra preamplifier, reflecting Ken Scott's production methods. This album didn't sound nearly as good before the new Nagra preamp was installed in my system. This preamp faithfully reproduced the Moon streamer's output signal, producing a version of this album that never sounded better coming through my speakers.

There are many, many reasons why I love this album. Beyond David Bowie's primary contributions, it is Mick Ronson's guitar work that made the Nagra Preamp II-S reveal its notable clarity and energy. On Bowie's previous album, Hunky Dory, the piano led the way, but on Ziggy Stardust, the recording gave precedence to Ronson's guitar. The Nagra preamp presented Ronson's Les Paul through Marshall amplifiers with a presence that was tough to ignore and easy to appreciate, even when it wasn't the loudest thing in the mix.

Mick Ronson's guitar continued to grab my attention, throughout the album, especially on tracks such as "Moonage Daydream", "It Ain't Easy", and "Ziggy Stardust", which all feature Ronson's massive-sounding guitar. When listening to this album through the Nagra Preamp, on every track featuring Mick Ronson, and even when he was playing rhythm guitar, I never heard it separated from the surrounding instruments like it did when the Nagra II-S was in the system. I think I listened to this album about five times during the review period.

Assume
One might assume that because this Nagra preamp was powered by tubes, it should have sounded tube-like. Not so. Even when I squinted my ears to hear these characteristics from the Preamp II-S, I could not detect even a hint of "tube sound." Its presentation sounded neither like a tube nor a solid-state preamp. The Preamp II-S sounded like an outstanding preamp. Period.

I suppose there was one trait of the Preamp II-S that made it sound a bit more tube-like, but this was a positive: it was the II-S's ability to maintain a dynamic distance between sounds. When two instruments or voices were located in the same place in the soundstage, not only could this preamp separate the two sounds, but it also made their volume differences much more audible. Its dynamic distance gave rise to an almost indescribable ability to hear "behind" each sound. I've also heard this trait in some very high-quality solid-state components, but it's more common in tube-powered equipment.

Near the end of the review period, I swapped out the Nagra Preamp II-S for the other in-house linestages, those that I listed earlier in the review. These linestages were all very high-quality components, but when I returned to the Preamp II-S, it seemed to have all the qualities of these other components, but enhanced their traits significantly. These refinements were true regardless of which trait I was considering.

Preamplifier: How Good Is The Nagra?
What makes a good preamplifier? Some want specific features, such as input/output types, tube or solid-state power, or a cabinet size to fit custom spaces. For others, price is key. But if sound quality is your priority, the Nagra Preamp II-S will fit the bill perfectly. Those with good systems to begin with will be very thankful to have acquired their Nagra Preamp II-S, even if it replaces an earlier version. Because of its high level of transparency, this preamp will also reward future upgrades of other components in their system. But its transparency might also be a shock to their wallet when it reveals weaknesses in other components in their system.

Throughout the review period, I heard the Nagra Preamp II-S deliver a realistic, unforced presentation that brought out the best in the music that passed through it. Highly recommended.

Specifications
Type: Vacuum tube stereo preamplifier

Output impedance:18 Ohm – Gain selection switch @ +6 dB 9 Ohm – Gain selection switch @ 0 dB

Frequency Response: 10 Hz to 50 kHz (+0 / -0.5 dB)

Dynamic Range: >125 dB (Gain selection switch @ +6 dB)

Input Level To 0 dB (Modulometer): 1 V rms (Gain at +12 dB) (Gain selection switch @ 0 dB, volume potentiometer @ 0 dB)

Total Harmonic Distortion (THD): <0.01% @ 1 kHz, 1 V rms out, no load

Crosstalk: >85 dB @ 1 kHz, 1 V rms out, no load

Vacuum Tubes (selected by Nagra Laboratory): Two 12AX7/ECC83 and one 12AT7/ECC81

Inputs: Balanced XLR and four unbalanced RCA 

Outputs: Balanced XLR and unbalanced RCA 

Dimensions: 15" x 11" x 3" (WxDxH)

Weight: 10.6 pounds

Price: $27,900 with included Compact PSU
$24,500 without power supply (for existing owners of Nagra MPS or Classic PSU)

Manufacturer
Nagra Audio Technology Switzerland, SA
Chemin de l'Orio 30A
1032 Romanel-sur-Lausanne
Switzerland

Voice / Fax: +41 21 643 7240
Website: NagraAudio.com

Sales & Marketing Manager USA And Canada
Rene Laflamme
Voice: (514) 826-4825
E-mail: rene.laflamme@nagraaudio.com