Nautilus Flagship Personal Audio Tubed Integrated Amplifier ampsandsound

There are no words to describe how incredible this was


Now just imagine if the Aeolus had been plugged in! :laughing:

Joking aside, beautiful picture :+1:

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So this is what those “thick and stiff” cables are for I assume?

Yes. Trying to tease out the sound differences between the Nautilus’ RCA vs XLR inputs (e.g. without or with input transformers), and upgrading to the Lampi finally allows this (albeit the Lampi is actually ‘faux’ XLR as it’s not a truly balanced circuit). So far not sure which is preferred, but also different cables.

Wow, that’s a beautiful stack! What DAC is that? Or is it another tube amp below the Nautilus?

It’s a Lampizator Dac.
He will have to tell you which model, I don’t know the brand except that they are expensive!

Hi @SebastienChiu it’s a Lampizator “Atlantic 3 TRP DAC”. Owning a Lampi was on my bucket list, and oh it’s so worth it; but as @robson said I’m really not willing to ever listen to the higher end stuff as the drugs just get more and more expensive.

It’s interesting since Lampi used to be more R2R designs, but their latest iteration went back to DS and in their Polish secret labs somehow made it sound like a blend of R2R musicality with a healthy dose of DS technical prowess.

This one (“TRP”) is called Tube Roller’s Paradise as it has a large flexibility with rectifier and power tubes, and so the sound can be very much fine tuned if you’re a tubehead.


That’s so cool. I’d love to be able to try that out eventually.

Thanks for the great in-depth explanation!

Okay, my turn for a Nautilus review :wink:

High-end audio is, for many of us, a solace of joy and amazement amidst the busyness and stresses of everyday life. As a 2-channel audiophile, I recall blessed memories of that ambiance and atmosphere being in the sweet spot of my listening room; after switching several years ago to a pure headphone system I have restarted the long journey to achieve sonic nirvana. I was introduced to Ampsandsound in 2021, and started with the Mogwai SE which significantly elevated my ZMF Verite enjoyment.

When I reviewed the Mogwai SE, I had a small “what if…?” inkling of Justin Weber’s bigger amplifiers. I was happy for almost two years… but eventually succumbed to the adulterous eyeing of better, bigger and sexier tubes. Or perhaps it was FOMO as I get older. I called Justin at the end of 2022 to chat, and there must have been some strange Jedi mind-tricks because my new Nautilus soon showed up at the front door.

How does it look and feel?

Unpacking the Nautilus first starts in a similar way as any of Justin’s other amplifiers. A large Seahorse case protects these tubed jewels against any possible adventures by UPS. Thankfully the 98 lbs wheeled case helped me roll this behemoth into my office. The physical effort alone foretells that there’s some monster inside compared to the smaller Ampsandsound amplifiers that I’m used to, but nothing prepares you for when you actually open the crate.

Holy cow. This thing is huge, and HEAVY. It feels more like a full-sized mega speaker amplifier than a headphone amplifier (reminiscent of those with the huge heatsink fins and weighs a ton and you get hurt by lifting it). You do not want to drop the Nautilus. It will cause a crater. I’m pretty sure no one will ever be able to steal this thing. Once you set it in place, pat yourself on the back and have a cold beer.

I have always liked Ampsandsound’s glowing-tubes-with-a-wood-chassis look across the product line. But his statement pieces, the Nautilus and Red October, are differentiated with a commanding modern yet classy look. The individualized color options add extra appeal as these amplifiers are meant to be a centerpiece; this unit has a textured scratch-resistant “Steel Blue” color which beautifully complements the tube glow during late night listening. Props for the excellent tactile feel of the stepped volume attenuator, connectors in the back of the amplifier instead of on the top plate, and a power switch in the front (finally!).

The first time I turned on the Nautilus, the first thing I noticed was what I did NOT hear. With it plugged directly into the wall (without power conditioner), with the ZMF Verites on the 100 ohm jack, I cranked the volume up to max. Despite potentially 6W rms into my headphones, I heard nothing. Complete black silence, no hiss. How’s that for a noise floor? The Nautilus’ specification indicates 2.1 mV @ 300 ohm and 1.5 mV @ 100 ohm of noise, and it was clearly quieter than my Mogwai SE.

A Slight Detour... but it was so worth it!

The intention was for the Nautilus to replace the Mogwai SE in my office headphone system, which consisted of an Aurender music server, Shunyata Alpha USB cable, Rega P8 turntable with Apheta 3 cartridge, and Vinnie Rossi LIO integrated front-end with his L2 DAC and L2 phono stage. The LIO’s tubed unity gain stage directly drove the Nautilus via DH Labs Air Matrix RCA interconnects. The Nautilus was plugged directly into the wall through a Shunyata V10 Venom NR power cord.

During my burn-in week, I noticed with the LIO at max output (~2V rms), I was listening to the Nautilus with the volume turned quite high at 2 oclock. Furthermore, even though the music was LOUD, it felt like the macrodynamics were somewhat muted. Justin, the ever gentleman and scholar, spent a lot of time troubleshooting my setup and suggested a higher source voltage to the Nautilus (or adding a preamplifier). To make matters more complex, the Nautilus’ XLR inputs incorporate an input transformer, while the RCA inputs do not. The subsequent month resulted in a complete remodeling of the rest of my system, including a larger audio rack (The wife asked, “Why are there so many boxes? Is this more of that audio stuff??”). The LIO DAC was replaced by a Lampizator Atlantic 3 TRP (3Vrms SE, 6Vrms XLR output), and the LIO phono stage was replaced by a Sutherland Little Loco mk 2. Various RCA and XLR interconnects were tried, and the DH Labs ICs were replaced with Shunyata Anaconda-S XLR, and a new Shunyata Alpha V2 XC power cord was added to provide limitless current to the Nautilus. This was the final system used for this review; the Nautilus volume attenuator was usually at maximum, and volume was controlled by the Lampizator’s gain stage. Tube complements include for the Nautilus (NOS RCA 5U4G rectifiers, NOS Amperex Bugle Boy ECC81 input tube, and JJ KT88 power tubes) and for the Lampizator DAC (Western Electric 422A rectifier, Tesla EL51 and Sophia Electric coke bottle KT88-ST power tubes).

Fortunately, the wife was unaware that my Nautilus purchase unexpectedly led to even more costly upstream upgrades. But lessons were learned. First, in order to really experience the Nautilus, the rest of the system needs to be of high quality; my starting configuration with the Vinnie Rossi was no slouch (and not cheap!) by any means, but the Lampizator/Sutherland combo allowed the Nautilus to sing at a different level. Second, consider the input voltage into the Nautilus. In my experience, 1-2V RCA is plenty loud, but 3V+ RCA is where the magic really happens. Consider yourself warned that the Nautilus rabbit hole can be quite deep; I jokingly blame Justin for my entire system redo, but the end result was a higher level of performance than I ever imagined. I have zero doubts that this amplifier will keep up with any future component changes in my system.

Let's get on with the show! How does the Nautilus sound?

Holy. Was that bass there before?

Those were the impressions and thoughts of the first songs through the Nautilus. Starting with Guns N Roses’ “Sweet Child O’ Mine”, the iconic guitar opening solo had such presence and body that left my jaw agape. Within the limitations of the recording quality, what was previously a complex blend of guitars and drums at 4:10 is now defined as individual instruments, each with its own personality and voicing. Similarly, the rapidfire opening of “Mr. Brownstone” was characterized by the leading edge attack of each guitar and drum strike, interposed with the briefest of black silence between the notes; having listened to these songs since middle school, I was brought to a higher level of appreciation of the band’s interpretation and tight timing between Slash, Izzy and Steven. The Nautilus’ speed is best exemplified by the clear and detailed impossibly-fast drum roll at the beginning of “It’s So Easy”; this millisecond-level distinction of each drum hit is easily blurred by many other high-tiered systems. Despite my prior familiarity with Gn’R, listening through the Nautilus feels like Axel taking me metaphorically into his jungle and back.

The amount of transparency, details, and quality of vocal realism and instrument timbre is insane. Lisa Loeb’s “Stay”, a song well known to many of us, sounded as if it was a new recording. Her voice was so pure and full of depth. Each guitar strum is clear from the melody to background. I hear mis-plucks, chair creaks and nails on strings that were previously missing. There are now background vocals that I didn’t know were there.

A few nights ago, I was so enthralled by the interplay between Norah Jones’ sultry voice, the microphony, and the twang of the strings on “Lonestar” that I had to call my wife over to have a listen. Soon she had her eyes closed, bobbing her head with a smile. With the lights off, whiskey in my hand, I was transported into the Norah’s recording studio.

The Nautilus truly excels at bass control and both microdynamics and macrodynamics. In La La Land Soundtrack’s "Someone in the Crowd’ at 1:28 the bass drum sequence has such a meaty kick and crescendoing excitement that repeatedly brings forth a silly grin to my face. More than once I looked around my listening room thinking the explosive sounds came from outside of my ZMF Verites. In Natalie Merchant’s “Carnival” the drums and double bass extend further into the sub-bass without rolling off or loss of definition; the abundance of headroom, power and control is a rarity among ANY speaker or headphone amplifier.

Then, I was transported to a front row seat for Michael Jackson’s “Man In The Mirror”. MJ’s voice was center-stage with the nuanced microdynamics in each fingersnap, his vibrato, each “naa naa naa” and “make that channnnnge”, while balanced with the macrodynamics of each drum beat. Whether it is The Phantom of the Opera, Dire Straits, Dave Matthews Band, Taylor Swift, or the Leningrad Philharmonic Orchestra, listening through the Nautilus is more of an experience than simply a great recording playback. This amplifier is by no means euphonic; instead it is very truthful with a twist of honey. Mediocre recordings will be shown as such, but with an amplifier this good, it is pretty obvious when an album is well recorded or not.

We briefly mentioned the Nautilus’ XLR vs RCA inputs and the former’s incorporation of an input transformer. Testing the two inputs with sets of Shunyata’s Venom-X SE and balanced interconnects, the XLR sound was preferred with a slight advantage in midrange and upper bass warmth and presence, resulting (in my system) an overall more coherent and balanced, musical picture. The RCA input seemed to bring the singers a bit forward, and leaned more towards an audiophile sound. Both were very good and depend ultimately on listener preference.

Like all of Justin’s amplifiers, the tube-rolling possibilities are endless. My Nautilus came with JJ KT88 power tubes, but I also tried GoldLion KT88s and Sophia KT88-ST. The GoldLions provided a slightly sweeter tone, but at the cost of bass extension and detail retrieval. The Sophias created more air around vocals and a larger soundstage, resulting in a somewhat more dramatic presentation, but some soloists seemed more recessed as if they were further from the microphone. But in my system, the JJs created the best balance of neutrality and magic.

How does it compare to its little sibling, the Mogwai SE?

My Mogwai SE ($3600 USD at the time of this review) has a special place in my heart. It has already set a very high bar to beat, and sings with an intimate, sophisticated and warm yet fun voice, but Nautilus has a clear advantage in transparency, handling of complex layered music, and has a noticeably more life-like timbre, probably due to more body and details throughout the frequency spectrum, bass heft, PLUS a lower noise floor. The electric guitar opening riff for Cranberry’s “Zombie” had more grunge, meat, grit and air, the increasing layering of the different guitarists had greater separation and definition. Each tambourine shake rings farther into the treble frequencies with a more natural decay. O’Riordan’s yodel is more expressive, and the presentation of guitars, voice and drums at 03:40 is significantly more separated as individual, defined notes in a cohesive picture. The macrodynamic swings from the Nautilus goes from ppp to fff, whereas the Mogwai would only go to ff. By no means would I ever fault the Mogwai for its high performance, but these observations are only noticed in the context of the Nautilus’ utmost performance and control. They were evident while enjoying the music, but the differences even more stark during critical listening.

Some would say, “But the Nautilus is $9,200!” Well, in this hobby, we are well familiar with the law of diminishing returns. While many products with stratospheric prices are often merely different, the Nautilus is clearly better than its smaller sibling. Could I live forever with the Mogwai? Yes, but only if I have never heard the Nautilus. If the Mogwai SE is a tuned V8 engine, the Nautilus is an unleashed V12. The Nautilus creates such an incredible sonic experience that defines the je ne sais quoi between the rare “top-of-the-line” versus the “superb” amplifiers, one which brings you closer to the heart and soul of each performance. Is this worth more than 2x the price of the Mogwai? To me, without question, yes! With every shit-eating grin that I get, song after song.

In Conclusion....

With the Ampsandsound Nautilus in my system, I can no longer imagine a further upgrade step (except perhaps adding desktop monitors via its speaker outputs). The other amplifiers in its league, depending on system synergy, might be more lateral rather than clear upward moves. My wish is that everyone would have a chance to hear the Nautilus and, like me, realize how great the music can be.

Each day now ends with my favorite moment, headphones on. I want for nothing, and have reached the headphone amplifier pinnacle of diminishing returns regardless of price.

Bravo, Justin!


Thanks to the tube gurus here, this special tube arrived. And brought the Nautilus to a new level.

Damn. Damn damn.


What tube is that? I’ve never seen a tube that looks like that before.

I’m not the owner, but I think it’s the Telefunken G73R.

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Upcoming review on the bottom box…


I really like the NOS tung sol 6550s but I found that the midrange wasn’t as accentuated with these as much as the KR audio KT88s which I find gives makes the vocals more alive
I heard the NOS Brimar footscray is beauitful, but I haven’t gotten a hold of them. Right now I really like the GEC a2900s
The rectifier I use are similar to the amperex 5AR4. I have a pair of the bugle boy 5AR4 which I have saved. I haven’t found a big difference between 5AR4s but the 5UGB give the music a wetter sound.

I found the 5UGB were a good combo with the 6550s, but with the KR audio KT88s, I like the 5AR4.


It’s like making a cocktail, isn’t it? A particular tube isn’t necessarily good or bad on it’s own, its all about what it adds to or subtracts from the sound of the other tubes.

For instance, the Brimar Footscray accentuates the midrange, which may be why I like it with the NOS Tung Sol 6550s, whereas it sounds like you’re accentuating the midrange with your KT88s.

As far as rectifiers are concerned, I’ve only compared 5AR4 and 5U4G, and preferred the former with the type of music I enjoy (predominantly rock/alternative). A friend of mine has told me that he’s found 5U4GB to be a happy medium between the 5AR4 and 5U4G in terms of sound, and that I might like the 5U4GB as a cheaper alternative to the 5AR4.

With the Nautilus, I really only rolled the input tube (12a_7), keeping the other tubes static. I didn’t realize how much of a headache I avoided by only rolling 1 tube until I bought my newest tube amp (LTA Ultralinear+) and decided to roll 3 pairs of tubes at the same time. I overexcitedly bought way too many tubes from eBay and ended up creating a spreadsheet of all the different combinations, along with the results of how they sounded. It took me weeks to figure out the sound of each individual tube.


Unless they were all absolutely new, you may need another dimension to track wear. Back in my early days I tried to control brightness through tube wear – I bought some that tested poorly on purpose. They all lacked high-end details, and were indeed easy on the ears as they croaked like frogs.

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This is so true! That sounds great that the Brimar accentuates the midrange - certain songs are just so sweet with that pronounced midrange. I’ll have to consider those the next time I venture down the tube rabbithole. My wife was so sick of tubes arriving to the house when I was in a tube buying frenzy.

Whats your favorite thing about the LTA ultralinear? I’ve considered the MZ3 extensively.The microzotl technology was interesting to me because I hear the tubes don’t get as hot.

At least you created a system - my box of tubes is a complete mess now!

I love your review. I had this tube in my cart for months and never got around to pulling the trigger but I always wish I had. I’m glad you’re loving it!!