Feliks Audio Envy

The Feliks Audio Envy is a flagship, Summit-Fi 300B Tube Amplifier. It starts at 6999 Euro, and we'll find if it's worth it in this review.


Today it’s time for something really, really special. The entire Ear Fidelity crew is Polish and we’re located in Poland, but we haven’t had any significant Polish products reviewed here. I know that many of you see Polish audio as something exotic and interesting, but we’ve been waiting for our domestic manufacturers to come up with something that might be able to shock the audio world. It’s called Feliks Audio Envy, and this review contains everything that you could get. 

The Polish manufacturer that I’ve known for the longest is Feliks Audio, as I used to listen to their Espressivo all the way back in the early 2010s. Back then, Feliks Audio was a small company that only offered the Espressivo, and it gained some attention on our Polish scene. A few years later the guys at Feliks Audio started to launch new, higher-end devices onto the market, and how surprised I was when I saw their table at the 2017 CanJam London. Surprised to the point where I approached them and asked (in Polish of course) – are you guys THIS Feliks Audio? What a dumb question, I agree.

We’ve been in touch for some time now, but everything changed at the 2022 Munich High-End exhibition. I’ve tried their newest flagship amplifier, the Feliks Audio Envy with some high-end headphones and immediately rushed to the Hifiman booth to try it with the Susvara. About 10 minutes into the listening session I knew that I’m experiencing something truly incredible, and discussed this review with Łukasz Feliks right away.

Then, it took a few months for my Feliks Audio Envy to be manufactured, and a few more to be reviewed, because even though this device is insanely expensive, Feliks Audio wasn’t able to keep up with the orders, which was incredibly great for me to hear. This was the moment when I said to myself: Yes, this is it, a Polish product that’s going to be something epic. My Feliks Audio Envy finally arrived in September, so this review has been in the making for quite some time, but you don’t simply sit and review a €7000 headphone amplifier right away. It takes time to truly understand what it is and what it’s capable of.

So, after intensively testing the Feliks Audio Envy with countless headphones, DACs, music genres, etc, I’m finally able to review it in a proper fashion. Bear with me, as this is probably the most challenging review in my entire career. 

A couple of words about tube amplifiers in general. The last couple of years has been all about solid-state amps, as they simply pair with planar magnetic headphones better. We’ve all experienced the shift towards measurements in audio, lack of distortion, low output impedance, etc. Many tube amplifiers on the market go excellent with dynamic drivers, but these kinds of headphones have been turning niche more and more. 

Feliks Audio saw that as well, and they challenged themselves to make an amp that goes well with planars. They have their hugely successful Elise and Euforia amps, but those aren’t ideal for planars either (The new Euforia EVO will be reviewed at Ear Fidelity as well!). That’s how the Envy was born, which is described by the manufacturer himself as “Class A Single-ended transformer coupled, balanced amplifier, powered by the legendary 300B tubes”.

Sounds yummy, doesn’t it? Oh, and it’s a mouthful for sure, so let’s dive right into it as I’ll try to answer the big question – is it really THAT good?

Packaging and Versions of Feliks Audio Envy

Let’s start with the unboxing experience. If you’ll order your Feliks Audio Envy anytime in the future, bear in mind that the box it comes in is absolutely huge. The box is made of good quality cardboard, nothing fancy or really special, but there’s a lot of foam insert to make sure your 7000 Euro amp arrives safely, don’t worry.

The amplifier itself is wrapped in a cloth that further helps keep it free from scratches or small blemishes during the shipping process. Apart from the Feliks Audio Envy, there’s a manual, tube guards, and of course…the tubes themselves.

Speaking tubes, you’ll have to make a choice when ordering the reviewed Feliks Audio Envy. Should you go for the standard version, or do you want to go all-in and get the “Performance” version (+€800). To be completely honest, if you’re paying €7000 for the amplifier to begin with, the performance version is just slightly above 10% price difference, so the choice should be pretty easy in my opinion.

What’s the performance version then? First of all, instead of using premium copper inside, Feliks installs UPOCC (single crystal copper) signal wiring inside the amplifier for improved sound quality. More importantly though, you’re getting Full Music 300B tubes, instead of Electro Harmonix Gold ones, and it’s a really, really significant upgrade. 

As I said, I strongly recommend going for the performance version, the price difference isn’t that big when you’ll take the base price into consideration, and if you’re going for the best of the best, there are no shortcuts. My unit is the Performance version, so the review will reflect my impressions of the fully upgraded Feliks Audio Envy.

Lastly, you can choose different wood finishes. I personally like the base version the most, but you can choose American Walnut for $200 extra, or go full custom for €400 – whatever tickles you fancy. The “stock” wood choice is oak and it just pairs so well with the entire visual concept that the choice was really easy for me. 

Tech and Design of Feliks Envy

Now let’s address the tech and design. Reviewed Feliks Audio Envy looks simply striking, it’s definitely one of the most epic and most beautiful headphone amplifiers ever made, and yeah…it’s absolutely huge.

The amplifier weighs 15kg which translates to around 33 lbs, so yeah, it’s a big boy. Make sure you’ve got plenty of space at your listening corner or on your desk, as it’ll take up a lot of space and its weight will require some good quality furniture. This aspect has its pros but it also has cons. First of all, you really see what you’re paying for, as the amount of materials alone is incredible and this just couldn’t have been done for less. Secondly, this is a statement piece, so if you’re looking for an amplifier that will be a conversation starter, I can’t think of anything better than this. 

However, in the world where small solid-state amplifiers are more and more popular, this is just an absolute behemoth that will probably occupy half of your desk, so this is definitely NOT a subtle audio device for your everyday usage. Additionally, it gets plenty warm, you won’t burn your fingers (as far as you don’t decide to touch the tubes after a few hours of listening to music), but it will make its surrounding a bit warm. If you’re living in a very hot area and you have no A/C, the Feliks Audio Envy might make your life even slightly more challenging than it is right now. Yeah, this was an exaggeration.

The design aspect that I absolutely love about the Feliks Audio Envy is the power “button”. You simply touch the surface that you can see in the picture above to start the magic, and this is so satisfying to do. In the world of power buttons and switches, now we’ve also got a touch button, and it’s just a joy to use. A very simple detail, but it’s these small things that elevate the experience from good to fantastic.

The volume knob is absolutely huge and again, incredibly satisfying to use. It’s buttery smooth, has a great range, and has just enough resistance for you not to accidentally turn up the volume significantly and blow up your eardrums. This is just literal perfection, the best volume knob I’ve used in a headphone amplifier.

Envy is a SET – Single Ended Triode amplifier. That means that all tubes used in the amplification are triodes. This is the most purist approach to tube amplifiers. It is not that unpopular in headamps, we do have a lot of SET amps with 6080 output tubes.

There are other things that set Envy apart. Lets start with the tubes used. 300B and 6SN7 (CV181) are the most linear tubes in current production. Linear tube means lower distortion, and simpler construction of the amplifier. 6SN7 is a double triode of medium gain which is very popular in first stages of amplifiers, in preamps and other tube audio that requires best performance. The 300B is a special tube. It is one of the oldest models around. It uses different technology, than the tubes you usually see. It’s a DHT – Directly Heated Triode, meaning the heater circuit is a part of the cathode. It’s the oldest construction of tubes and it is praised as the best sounding.

There is no free meal, and the 300B is very demanding to sound good. The engineers have a tough challenge to make it sing as it is harder to use than regular tubes. Only the best can make the heating circuit that is dead quiet and good sounding as it is directly in the signal path (acts as cathode). The another thing that sets apart Envy is the transformer coupled output. Most tube headamps are OTL – Output TransformerLess. That’s why most of them sound the best with high impedance headphones, or use solid state buffering. Tubes are just not good at pushing the current into low impedances (and even 300 Ohm is low for a tubes, not mentioning 50 Ohm loads).

The oldest, and best answer is the output transformer, which takes high impedance, high voltage output from the tube amplifier, and scales it down to lower voltage and lower impedance. This allows to match the headphone impedance allowing for the best power transfer, and lightens the load on the tubes, bringing lower distortion of the amplifier.

What are the cons? Weight, there is a reason Envy clocks in at a healthy 15 kg. The even bigger one is cost. A high quality, low distortion, high bandwidth transformer can be worth it’s weight in gold. And it is not a too big extrapolation. Especially nowadays, tube output transformers are considered exotic, and not many manufacturers can provide the quality product the Feliks wants to use. The Envy is much more similar to speaker amplifiers, than it is to headamps. The nice comparison would be the legendary SunAudio SV-300B. 

Envy produces up to 8W (around 5% THD) of power, but the useful power is around 5W (below 1% THD), which is still more than you might need. This power can be delivered with 3 output gain settings: low, medium and high.The bandwidth is also solid at 18 Hz – 40 kHz +-1dB. This means that the audio spectrum will be reproduced perfectly, with no audible drops.   

Build Quality and I/O of Feliks Audio Envy

Okay, let’s get to the actual build QUALITY. So, the Feliks Audio Envy is built and finished marvelously, it’s in a league of its own. The wood finish and overall attention to detail are mind-boggling in every single inch, this is definitely what a high-end device should look and feel like. Just look at these little details and the quality of the print, there are simply no corners that have been cut. I really appreciate it. 

Also, the last couple of years was all about going simple in terms of the design, which caused one small problem – many amplifiers look very similar now, even when they were released by two different companies. You know what I’m talking about – black or silver CNC machined aluminum, boxy design, small footprint. In terms of functionality, this kind of approach is definitely correct, but where’s the fun in it? Envy simply went bonkers on that thing and they definitely weren’t scared of creating something that looks big, muscular, and “classic”. 

As far as the I/O goes, this is just an amplifier, so you won’t find any digital inputs and outputs, but as far as analog goes, you’re pretty much covered. At the back panel, you have 3 sets of inputs (two RCA and XLR), which allow you to plug the Feliks Audio Envy into three different DACs, CD players, or Phono Preamps. Additionally, there’s a preamp section that allows you to use the Envy as a preamp in your stereo setup, and you can plug it into an external power amplifier and get that 300B magic onto your speakers as well. This is a great addition, as I’m planning to use the Feliks Audio Envy in my stereo setup in the near future myself. Of course, the preamp section has both RCA and XLR outputs, to make use of the balanced topology. I will definitely update this review once my stereo setup is ready and I’ll get my opinion about the Envy as a preamp.

Let’s now turn the Feliks Audio Envy and look at the front. First of all, you have two headphones outputs, a 6.3mm Jack and a 4-pin XLR. There’s no 4.4mm output, it would have been a great addition, but this plug is still rather exclusive to IEMs, and why on earth would you buy this monster of an amp to drive your IEMs? I mean…you can, but seriously?
Next up, there’s an “Impedance” selector which allows you to switch between low, medium, and high. To be honest, this selector should be called gain, as impedance selectors are not relevant anymore. The Susvara has an impedance of 60Ω, yet it’s harder to drive than any dynamic driver headphone ever built. 

So treat this selector more like a gain control, and if you plan to use the Feliks Audio Envy with the Susvara, just go straight to the high setting and never look back. UPDATE : Nowadays the Envy comes with a gain selector instead of the impedance one. 

Next to the Impedance selector, there’s an input selector as well, which lets you choose between three different inputs that I’ve mentioned earlier. The selectors work great, they have a nice click to them and yet again, they are not too firm, nor not too smooth. What’s there more to say about switches?

Sound of Feliks Audio Envy

This was a rather long intro, but I had to go in-depth with this one. Special products like this require special treatment and special attention to detail.

However, this is an amplifier, and the most important thing it can offer is a high-quality sound. You won’t be spending that much of your money on furniture (or if you want to, just get the Herman Miller Eames). So, the Feliks Audio Envy was made to run every single headphone on the market with authority, while offering that legendary, sophisticated timbre of the 300B tube. Does it deliver on that promise?

Before I’ll answer that question, I want to address a very important aspect. You see, tube amps were hugely popular back in the day, and even as far as 10 years ago, tube amplifiers were very popular thanks to their great synergy with headphones like the Sennheiser HD650, HD800, AKG stuff, and many, many more. Then came planars that have changed things significantly, as most tube amps weren’t suitable anymore. 

However, I always liked tubes, even though I surely appreciate a good solid-state sound as well. Tubes just have that magic about them, a timbre and sense of realism that is just hard to explain. Additionally, it’s old-school, it’s hot, big, chunky, non-practical, and very, very climactic. Nothing beats the slight, orange light coming from tubes at 3 AM in a pitch-black room, and you cannot convince me otherwise. I’m a big fan of functionality, to the point where the most used pair of IEMs in my arsenal for the past couple of months are the AirPods Pro 2. Are they the best that I have? Definitely not, but are they the most convenient to use? YES.

But, this hobby is not just about functionality and convenience. Actually, that lack of convenience makes you focus on the entire aspect more, which improves your listening sessions in my opinion. It’s the same with vinyl. I love it because it’s so impractical and inconvenient, that it MAKES me sit and enjoy the entire album at once, with no skipping or switching the song every 5 minutes. That kind of inconvenience serves a purpose, and in today’s world, where all of us are constantly distracted and oversaturated with content, something that makes you wait and contemplate can be worth a lot.

Well, yes, you’ll have to wait about 40 minutes for the Feliks Audio Envy to reach its optimal temperature to sound its best. Yes, using it for an hour at a time is totally pointless. Yes, it is huge and heavy. Yes, it gets hot and the tubes have a lifespan. This is definitely NOT a “one-and-only” headphone amplifier for your desk, to use while watching YouTube or playing games. Because of all of this, when you decide to power it on and listen to it, you’ll appreciate it more, treat it as something impractical so much, to the point where it serves a very practical purpose – to make you focus more. 

Okay, this could have been a little too poetic, but I hope you got my point. Another aspect that I’d like to focus on is the entire solid-state vs tube situation. This amplifier will never measure as well as something like the Topping A90, which is like 1/10 of its price. So what? I’ve had both, and I would literally NEVER choose to listen to the A90 over the Envy, and it’s not a close call. These two are miles away from each other when it comes to the sound performance, and no measurements and audio objectivist is going to convince me that I’m wrong here, so don’t even try.

The energy, timbre, dynamics, sweetness, and punch of the reviewed Feliks Audio Envy are all the best I’ve ever heard from a headphone amplifier, beating some great amps on its way. To truly understand the level of audio goodness that this huge guy outputs, you’ll have to try it with your favorite headphones. Hopefully, this review will help you make a decision of trying the Envy, or you’ll simply blind-buy it, but trust me: No words I’m going to use here are going to be enough to express the number of emotions that the Envy delivers. But I’ll try my best!

So, let’s start with the BASS. Yes, that capslock was intentional, as the Feliks Audio Envy delivers an absolutely crazy bass response with every headphone that I’ve tried it with (and I’ve tried a lot). The first myth is busted right away: Tube amps don’t have enough juice and punch for an excellent bass response. Busted. The low frequencies here are incredibly powerful, rich, dense, and perfectly controlled, to the point where you won’t believe that it’s a tube amp. This is probably the biggest surprise that the Feliks Audio Envy has for you, as it’s definitely not a soft, warm-sounding amplifier. 

Even with the Hifiman Susvara, the reviewed DAC/Amp is able to deliver a very powerful, impactful, and firm bass response that these headphones lack very often. I’ve always seen the Susvara to be a little too anemic and calm in the bass department for my liking, but ever since I’ve got the Feliks Audio Envy for sake of this review, this feeling is gone. And when you’ll try it with something like the Meze Elite or the Rosson RAD-0 is when you’ll experience a bass that is just absolutely insane. 

Of course, the resolution, speed, control, and texture are all top-tier (as you should expect that this price), but to have all that aspects married with such energy and power is a rarity that is definitely worth paying for. It’s immediately prominent that the Envy has ultimate control over every driver, resulting in a lightning-fast response time, which further improves the resolution and dynamics. 
Because of all of this, the Feliks Audio Envy is a Jack Of All Trades, as there are simply no headphones or music genres that it doesn’t perform incredibly with. The bass response is just highly universal, to the point where it doesn’t overdo anything, but you’ll never have a feeling that it’s lacking in power or slam. Another great aspect is the spatial capabilities of the bass itself, which is quite hard to achieve in headphones. 

If you’ll play a track with multiple bass instruments, they all will resonate in different places around your head, which is a very unusual yet highly natural feeling. Let’s take a song called “Abraham” by Miles Mosley, which has that big double bass. It sounds so rich, yet incredibly natural and well-controlled, to the point when it’s never going to interfere with the rest of the instruments. The amount of air pushed just feels right, it doesn’t resonate infinitely, yet it’s not too fast and lean at the same time. Just perfection.

The midrange is where the 300B shows its legendary status. You see, I don’t know how experienced you are in the stereo market, but 300B amplifiers have been incredibly popular in high-end for many, many years now. That’s because of its truly unique timbre, which shows mainly in the midrange. These tubes just make the music come to life, but at the same time, they don’t sound overly “tube-y”. You see, I always imagined the perfect amplifier to sound like a good tube amp, but with the technicalities of a top solid-state one, and the Feliks Audio Envy finally showed me that it’s possible and that it exists. Having that in mind, don’t expect the Envy to sound like any other tube amplifier you’ve ever tried, because it definitely won’t. 

Most people that have tried it, including my friends and myself, have found it less “tube-like” than they expected. And this is actually the best thing that could have happened in my opinion, as you don’t need a lot of that 300B magic to make the music sound the way it should. The high-end audio is all about proportions, not overdoing anything, yet giving us something unique and pleasant. 

This type of sound gives you a truly different experience. The albums that you know perfectly suddenly sound a little bit different, and not in a bad way, but not in a “this is what high fidelity sounds like!”. No, it just has a different flavor, that is incredibly fun to experience and gives you a feeling of dealing with something unique. I always thought that high-end audio isn’t really about sounding ultimately better, but rather creating a sensation of experiencing a sound that is highly colored, but in a specifically designed way. High-End often isn’t really about chasing the best measurements and purest audio signal. It is designed to sound in a “specific way”, which I can compare to fine dining. 

Why am I expressing this so much? Because the 300B tube is in a lot of ways just what I explained. If you want ultimate transparency and a sound that is perfectly uncolored,  just get a solid-state amplifier. If you’d like something that has a spice to it, but it’s not just a spice but rather a meticulously seasoned dish that sounds “as intended”, then I believe that there’s nothing better than 300B in the world. This tube has so many enthusiasts to the point where I know a handful of people that will never buy a non-300B amp ever again in their lives. Well, who can blame them?

Well, that was a lot of words, but what does all of that really mean? I’ll give you an example. “Lovely” by Billie Eilish and Khalid is a great example of a song that is insanely emotional and simply melodic, but the mastering (while pretty good actually) kind of kills those emotions in the vocal range. These vocal parts often lack a bit of softness, natural thickness, and harmonics, resulting in a sound that is very energetic, but a little bit emotionless in my opinion. The same song played via the Feliks Audio Envy gets that beautiful timbre in the midrange, and suddenly the music flows effortlessly with a lot of richness to it. 

It’s not that it starts to lack anything because it overpowers certain portions of the sound, hell no. It just adds that final touch to simply improve the richness and desirability. That’s what’s worth an extra penny in my book. I’ve heard a neutral and transparent sound hundreds of times in my life, just give me something flavorful and unique, especially if I’m spending many, many thousands of euros/dollars. While enough has been said about it, I must highlight the fact that the Feliks Audio Envy DOES sound very natural and accurate, as all of those 300B perks are subtle to the point where it’s literally the perfect amount. When you’ll listen to it you’ll immediately hear that this amplifier has been tuned very, very lovingly.

The treble is yet again incredible. I know this might be starting to get boring, but that’s just a fact. The amount of shimmer, the transient response, the decay, saturation, and proper weight of instruments. Everything sounds just fantastic to the point where there’s literally nothing even remotely wrong with this treble response. It never gets too hot, it’s never veiled, dark, or muffled, it is just ideal. Something that basically no solid-state amp can do for me is to reproduce the natural weight of cymbals. While many get to sound very fast, snappy, and detailed, it is the thickness and weight of the sound itself that does that for me. If you’ve never heard a percussion live, just go to the nearest music shop that has one on display and start bashing those hi-hats. It’s not harsh or sharp, it’s rich, ringing, and very intimidating sounding, and that’s exactly what the Envy can reproduce. 

Once again, a tuning designed for what the real instrument sounds like, not what’s the most accurate on the frequency response. I know that I’m going to piss many audio objectivists with this sentence, but hey, here it goes anyway. I said it a million times and I’m going to say it again: I’m in this hobby long enough to appreciate Harman and perfectly neutrally tuned gear, but I’d rather quit this hobby than listen to the perfectly flat system for the rest of my life. No, thank you, I’ll leave that one for measuring devices, I’m a human being and I want my emotions in my music, this is THE ingredient that is the most important, and nothing is going to convince me that it’s not. Actually, audio objectivists will never ever even start to consider buying an amp like the Envy, so they probably aren’t even reading this review. 

Well, jokes aside. You know “Dreams” by Fleetwood Mac, it has some intensive treble action, and this track sounds absolutely ridiculous on Envy. The amount of energy, the sublime texture of it, crisp yet naturally rich and smooth, you’ve got everything that you could have asked for. And more. Another great example is the “Chocolate Chip Trip” from the latest Tool album, Fear Inoculum. I’ve used this song many times now in my reviews, but it just never gets old. Just go and play it, it’s such an incredible show of Danny’s godlike skills, and it’s well-mastered as well. So, this track just gets so intense on Envy that it gets shockingly close to a true live concert. 

You immediately start banging your head, and you can’t help it. This once again proves that the Envy is NOT just another 300B amplifier that sounds unique and tube-y. This is peak solid state level of performance, seasoned with some high-end tube magic powder to create a type of experience that you simply cannot fake. This is big brain stuff, no other amplifier that I’ve heard could have done this even remotely close. Woah.

The amount of treble you’ll get will also hugely depend on your headphones of choice. The Meze Elite focused more on weight and richness, without going to outer space when it comes to scale and extension. But, when I switched the Elite for the Hifiman Susvara, the treble immediately opened up, went further up, and scaled better. This is a brighter-sounding combination, no doubts about it, so you can easily control the amount of treble with your headphones. At the end of the day, you don’t want an amplifier that is going to highly alter your headphone’s tone, to the point where they’ll suddenly start being a bit harsh or overly bright, right? The Envy is just so sophisticated and well-tuned, that it never gets in the way, but you always know it’s there. 

The soundstage, will it surprise you at this point if I’ll rate it as exceptional? Doubt it. Yet again, absolutely brilliant performance with infinite depth and width, ultra-precise imaging, layering, and separation. If you’ll try the Envy with great staging headphones like the Susvara, HD800, or the HEDDphone, you’ll be amazed of how a pair of headphones can project the sound outside of your head. Say goodbye to the music playing in your head, these days are long gone for Envy users. 

Because the Envy has so much power and it delivers it with such authority, the complete control over any driver gives you an endlessly low response time, which allows the soundstage to sound as precise as it gets. Again, the harmonic characteristics and that unique type of presentation further extend on that feeling, as many great solid-state amplifiers tend to somewhat struggle with proper staging. While the Topping D90SE is a DAC, not an AMP, I will never forget how non-existent the depth is on that DAC. 

Everything is very close in front of you, everything in the same distance, and there’s nothing you can do to improve that, this device just has no soundstage depth and you have to accept it or choose a different one. The Envy on the other hand shows again why it’s worthy of being a TOTL, end-game piece of audio, as it just delivers a performance that is just as perfect as it gets nowadays. I truly don’t know if you can get any better right now, regardless of the cost. The amount of air, scale, ultimate accuracy, and resolution is insane, you can simply pinpoint every single violin in the recording, even if there are 12 of them. 

Nothing is blooming, nothing gets in the way of anything, every single piece of audio source has its place and it does respect its boundaries, squeezing every single drop of air it has to play. I really don’t want to write any witchcraft saying that this amplifier creates a soundstage that is like standing in the middle of a huge field with instruments as far as 100 meters from you, I’m not that crazy…yet. But when the credit is due, I have to give it, and for me, the soundstage capability of the Envy is just as good as it gets in 2023. Absolutely stunning.


Hifiman Susvara

Let’s start the pairing paragraph with an obvious choice. The Hifiman Susvara is well-known for both its incredible sound quality, as well as for being ridiculously hard to drive. Up to this day, you had basically next to zero choices for tube amplifiers to run your Susvara with. Some people used stereo tube amps via speaker outputs, and while this is a way to do it, it’s definitely not ideal.

Here comes the Envy, which pairs absolutely beautifully with the Susvara. As I said in the introduction, when trying the Envy at the Munich High-End show, I immediately ran to the Hifiman Booth and borrowed a pair of Susvara to try that combination. I was blown away to the point where I basically had to get my hands on the Envy for a longer time, and yeah…here we are. 

So, this pairing is really special. Susvara is known for its natural, fatigue-free, and organic presentation, and the Envy just empowers these trademarks while giving you all the dynamics and slam you’d ever need. The Susvara finally came to life when it comes to bass performance, where its rather soft and delicate low end turned into a monster. No, it’s still not a bassy-sounding headphone by any means, but there’s slam, impact and rumble now to be found, and quite a fantastic one actually. Apart from that, the rest of the frequency response sounds absolutely spectacular, with a rich and organic, yet technical and crisp midrange and that thick, insanely detailed treble. 

The soundstage is definitely one of the best I’ve ever heard in a headphone, and all of that creates a sound quality that is just mesmerizing. The Susvara is such an epic product on its own, but when paired with the Envy you’ll really get a sense of experiencing something special, and ultra-high-end. I still imagine myself around 10 years ago, and how insanely shocked I would have been if I got to try that setup back then. This hobby has improved so much over the last decade that it’s the main reason I’m still in love with audio. 

I’ve seen a lot of people chatting about the Susvara + Envy pairing on Head-Fi and on Facebook, and I must admit that this is one hell of a setup that will definitely satisfy literally every high-end audio fan. I’ve heard stereo setups that were more than 10x more expensive that didn’t offer this level of immersion, richness, and detail reproduction. I honestly think that this pair could rival behemoths like the original Orpheus, which might give you an idea of how great it is. Susvara fans are no longer limited to solid-state amplifiers, as it has been for many years now. There’s a new kid in town, and it’s making quite a fuzz – and the fuzz is justified. If you own the Susvara and you have been struggling to find the perfect amp, you HAVE to try the Envy. 

Rosson RAD-0

When I received the RAD-0 and the burn-in process ended, I immediately plugged them into the Envy, and yeah…I finished at 5 AM. The RAD-0 is a highly musical pair of headphones that are designed to provide fun while also being great at monitoring.

What’s great about this pairing is that both devices shine in quite similar areas. While being very good from the technical point of view, they do have their unique type of presentation that is incredibly fun to listen to, but it’s not to the extreme in any way. The RAD-0 has a wonderful bass response, and when paired with the Envy, it gets even better. Rich, strong, well-controlled, and marvelously tactile, this is the bass response that I absolutely love. I actually prefer the bass response of this pairing to the flagship Susvara + Envy pairing, mainly because it’s even more energetic and punchier and it hits harder. Yet again the Feliks Audio Envy has absolute control over the driver, which gives you that highly dynamic and firm bass notes. 

When it comes to the midrange, you’re yet again getting that rich, full-bodied, and flowing tonality with exceptional resolution and detail. The RAD-0 doesn’t offer a soundstage that is on the same level as the Susvara, but it also sounds quite a bit closer to you and more intimate, which performs great with 300B tubes. You’re getting that sense of a private concert in a small room that feels very welcoming and calming. 

This pairing does great with every music genre, but it shines in electronic music, rock, and everything that needs a lot of energy and punch. What’s interesting is that new mainstream music sounds absolutely ridiculous here, so this setup is perfect if you like todays music. Energetic, fun, quite forgiving but highly insightful at the same time. Definitely a great pairing, and while the price difference between the two products is quite big, I can definitely recommend the Envy if you own the RAD-0. They just go wonderfully together.

Meze Elite

The current flagship of Meze Audio, the Elite is my second favorite pair of headphones right now. It’s a pinnacle of what a Daily Driver should be – beautifully tuned, forgiving, and welcoming, paired with the best build quality on the market. The Elite is my go-to pair when I simply want to listen to music and enjoy it, without overthinking about what to listen to or what to pair it with. Just plug them into anything that is near me, click play, and enjoy your time. There’s no other headphone that does this for me in a similar fashion, and because of that, I can say that I’m a huge fan of the Elite.

So, one of the biggest pros of the Elite is its ability to basically sound great with everything. How does it go when we plug it into a 300B beast? Well, it does exceptionally well. The Elite definitely scales up with better equipment, just not as much as the Susvara for example. Luckily, the Envy is not just about its raw technical performance, but also its magical, rich tuning which the Elite definitely pairs well with. Yes, the Elite does not need a smooth and magical-sounding midrange from the amp, as they do have that kind of midrange performance on their own. But when paired with the Envy, this feeling is not overpowered suddenly. 

Because of that, this pairing is perfect for late-night, chill listening sessions or to watch movies and have some fun. There’s literally nothing that you’ll pinpoint and call “wrong” in the sound, everything flows and it just sounds…effortless. You definitely don’t need to buy the Envy immediately if you own the Elite, as this headphone works beautifully on its own, but if you have a spare 7000 Euro, you definitely should try this combination. This is the type of sound that would have been chosen by many hardcore 300B stereo fans out there actually, and I mean it. If you don’t want to chase the absolutely best detail retrieval, the most neutral type of sound, and absolute transparency, this might be the setup to go for. Rich, soft, romantic, incredibly addicting, and just musical. This pair sounds like music, something that should be really, really important for you. 

Final D8000 Pro

Now let’s turn the table and go in the opposite direction. The D8000 Pro is everything that the Elite isn’t, and vice versa. Very technical, neutral, and reference-sounding, this feels like the perfect candidate for the Envy, right? Yes, these two yet again pair fantastically. In my opinion, the D8000 Pro definitely needs a bit of richness, softness, and magic to counter its highly neutral, and to be honest, boring tuning. The Envy does that beautifully, as the Final flagship suddenly turns into a much more musical and enjoyable headphone. Another thing is that the bass response of the D8000 Pro is very unusual for a planar headphone, being more reminiscent of a dynamic driver. It slams hard and has great attack and decay, and the Envy further improves on that. 

Here you’re getting an intense low frequencies action, with some of the best dynamics you’ll be able to find in the planar world. While not as texturized as the Susvara, it slams harder and roars more, which might be highly desirable for many. The rest of the frequency response is countered by the Envy in the perfect fashion – it just improves the overall smoothness and realism, while not worsening the overall technical capabilities. Because of that, you’re still getting that fantastic detail retrieval and resolution, but it’s paired with a tone that is slightly more natural and enjoyable now.

This pairing is a perfect example of how two elements can help each other. The D8000 Pro is definitely not the perfect pair of headphones (hell, there are no perfect headphones, to begin with), but when paired with the Envy it definitely goes in the right direction. If you own the D8000 Pro and find them to be a bit too technical, too neutral, and fatiguing, the Envy is the perfect amp for you.

Audeze MM-500

This is the same as the D8000 Pro. The MM-500 is a technical, neutral-sounding headphone that even though it offers excellent detail and resolution, might be a bit too much for you. The Envy once again tames this headphone to become more enjoyable and more forgiving, while not sacrificing its excellent transparency and coherency. Yes, if you own the MM-500 then you probably want that ultimate, neutral tonality, but maybe you’d like a second amplifier that will turn your setup into a more “enjoyable” experience.

Here comes the LCD5 as well, as its frequency response is quite similar to the MM-500, and given their price, they are a more “logical” choice for the Envy than the MM-500. Yet again, the LCD-5 focuses hugely on the midrange, it is a mid-forward headphone, and the Envy should love that kind of performance. At the end of the day, we’re talking 300B amplifier, and its biggest strength is in the midrange, so a mid-forward, flagship pair of headphones should be a fantastic pairing. Unfortunately, I don’t have the LCD5 at my hand, so I cannot test this pairing, but it seems logical that it would have been a great combo. Let me know if you tried it.

Hifiman HE1000se

Now onto the little brother of the Susvara, the 1000se. This pair is very efficient, and you can run the 1000se out of basically everything, even a potato large enough should be enough (please don’t try it). 

So, do you need an amp like the Envy if you own the 1000se? Definitely not. But will the 1000se sound great with it? Absolutely yes. It’s not only about what the headphone “needs” but rather what it “could use”. And the 1000se can be a touch too bright and lean for many, especially when paired with very neutral amplifiers like Topping or SMSL. Here comes the Envy with its insane bass response, and that beautiful, rich midrange to save the day. This amplifier made the 1000se so much more enjoyable for me, less fatiguing, and more mature sounding actually. While this model doesn’t really benefit from the sheer power of the Envy, it surely appreciates the tuning that changes the response here and there to achieve a more high-fidelity experience. 

But, there’s a big risk. If you own the 1000se and you’ll end up buying the Envy, then I already know how it’s going to end. You’ll be amazed of your setup and you’ll swear that you ain’t changing a thing in the future…but sooner or later you’ll get your hands on the Susvara and try it with the Envy, and boom, you sold the 1000se, and bought the Susvara. Well, mission accomplished, you finally made it to the end credits, right? Right.


I’ll be doing the comparisons differently this time. I don’t have anything remotely close to the Envy at my desk right now, but I’ve heard the Susvara on many, many amplifiers, which I had here at my disposal at a time, so I can give you something at least.

First of all, I haven’t tried the Bakoon (now Enleum) amplifiers in a long time, and when speaking about Woo Audio, I only have had the WA22 for long enough to be able to give you a no-bs comparison.

So, long story short, the WA22 doesn’t even come close to the Envy. There you are. Comparing these two is really pointless because the Envy sounds so much better in every aspect. Man…I really have to put my hands on the WA33 to really have a good rival for the Envy. Hopefully, I can update this review in the future when I’ll have the WA33 side-by-side with the Envy.

What I can for sure do, is compare the Envy to the Octave V 16 Single-Ended. This is also a big-boy amplifier, but instead of using the godlike 300b tubes, the Germans went with a KT120. Well, no surprises here – the Envy completely demolishes the V 16 when it comes to energy, control, timbre, and resolution, and it’s not a close call. Don’t think that it’s because it’s more expensive though, because actually, the Octave is significantly more expensive than the Envy, coming at around 10000 GBP. Ouch.

So, the Envy sounds a lot more natural, sophisticated, powerful, and rich than the V 16. I’m not saying that the Octave is a bad amplifier because it definitely is not. The Envy just sounds better, especially with very high-to-drive headphones like the Susvara. And this difference is obvious, you don’t have to really focus on it. The detail retrieval is superior, the resolution and slam are both in a completely different class, and the timbre is miles ahead of the V 16. I’m sorry Octave, but it looks like your V 16 isn’t relevant anymore. Well, to summarize that comparison as simply as I can: 300B > KT120. Period.

Next up, the Ferrum OOR. I actually had the OOR for about 3 months in 2021 and had a really good time with it. The OOR is a fantastic amplifier when it comes to value, as there’s probably nothing that runs the Susvara so well in its price range. However, yet again, it doesn’t stand a chance with the mighty Feliks Audio Envy, which is just more powerful sounding, while also being more detailed with better tonality. The OOR is a natural-sounding amplifier that is actually quite smooth for a solid state, but the Envy is a real deal. If you’re on a “budget”, definitely buy the OOR as it is a fantastic piece of gear, but if you want the best of the best, your eyes should be set on the Envy. 

However, these two offer different approaches to sound. The Envy is definitely more colored of the two, with a more “magical” and tube-y sound (well, that’s logical isn’t it?). The OOR on the other hand is sounding more like an ordinary amplifier, so it will never be able to reach that incredible timbre of the Envy. The price difference is huge though, so my easy recommendation goes to both. Different levels, that’s all. Both are excellent.

Another comparison worth mentioning is with the Cayin HA-300 (mk1). Both amplifiers use 300B, but as far as functionality goes, the Cayin is  victorious here. You can plug loudspeakers into its speakers outputs, that’s a incredible addition if you ask me, and I wish Envy had speakers outs as well. However, when we’ll get into the sound, the Envy is a clear winner here. The HA-300 is definitely warmer of the two, thicker sounding with more tube influence into the sound. The Envy however hits much harder, is faster, more detailed and has a better soundstage. The difference is quite significant actually, with Envy being a much better sounding device. On top of that, it while looks are highly subjective, its build quality is more impressive as well. Cayin is well-made, don’t get me wrong here, but there’s just more about the Envy that makes you feel you’ve got something truly special on your desk.

Feliks Audio Envy – Summary

Kudos if you made it this far. This review was incredibly fun to do for me, and the results exceeded my expectations.

The Feliks Envy is a pinnacle of the High-End headphones market today. It’s an amplifier that checks all the boxes and then it does even more. Fantastic technical performance paired with timbre to die for, this is a true statement piece that should place Feliks Audio on top of the game, and it probably will in time. The Envy is an incredible amplifier to pair with every high-end headphones on the market, as it will surely run everything that you plug into it. On top of that, it looks marvelous and is built with such perfect craftsmanship, that even looking at it and touching it gives a smile on your face. A true State Of The Art device, in every single aspect. Congratulations to the entire Feliks Audio crew for creating this monster. It must have been quite a long journey for you guys, but you made it. Wow.

Highly Recommended.

Big thanks to Feliks Audio for providing the Envy for this review. I wasn’t paid or asked to say anything good or bad about this product, all of the above is just my personal, unbiased opinion.