Feliks Audio Euforia EVO

Feliks Audio Euforia Evo is a High-End OTL Tube Amplifier. Its price starts from €2699 and in this review we will check if it’s worth it.

Introduction to the Feliks Audio Euforia Evo review

Feliks Audio Euforia Evo review, main photo

Some time ago I visited Paweł’s place when he was preparing a review of the Feliks Audio Envy. I used to listen to the amp for a while and my only reaction was “PAWEŁ I WANT IT”, unfortunately, he wanted it even more. Later on, I had an opportunity to listen to Feliks Echo 2 and I was impressed that such a cheap (regarding its handcrafted in the EU, €899 isn’t so much) OTL amplifier can sound that good. And after a couple of months, the time has come for Euforia Evo, the latest headphone amplifier in Feliks Audio lineup.

But first, let me write something about the company. Feliks Audio is a family business based in Poland, they are a boutique manufacturer of hand-crafted tube (I know, I know valve is the only right name for this component) amplifiers with over 20 years of experience. Their products combine a passion for authentic sound, meticulous attention to technical details, and a beautiful finish. The company adheres to a philosophy of design simplicity, which involves reducing the number of elements in the projected signal path. This approach guarantees that the sound produced by their devices is genuine and unadulterated.

Mr. Henryk Feliks, the founder of the company but also an electronics engineer, is a big fan of OTL amps. He accepted the challenge of creating the amplifier that will be able to handle most of the headphones in the market, including planar magnetic ones and here it is – FeliksAudio  Euforia Evo, so without further ado, let’s move to my first review of the tube headphone amplifier (ok, second one, but let’s say that the characteristics of the triode at my university electronics course don’t count as a real audio gear review).


The box that the reviewed Feliks Audio Euforia Evo arrives in is pretty big, the only bigger box I’ve ever received with audio gear was the one containing Fyne F500 – a pair of bookshelf speakers. The cardboard is of good quality. Inside there is a foam insert that ensures that the amp and what’s more important the tubes made of glass will arrive in one piece.

Inside the package, there is an amplifier, four tubes (a pair of driver tubes PSVane CV-181 Mk2 “Gold” and a pair of power tubes 6N13S), a power cord, and a user manual. What’s important is that the tubes are paired, so you don’t have to worry that the channels will suffer the imbalance.

Tech, design and build quality

Let’s say that when I opened the box and put the Feliks Audio Euforia Evo on my desk I did not feel euphoric at the sight of it (ba dum tss…), I didn’t like the color of the device, but after some time I think it would be boring when it would be another black, or silver stuff. Almost like Mercedes-Benz cars sold in the current decade, black, silver, white, silver, gray, or silver, now Feliks Audio Euforia Evo breaks this monotony with its brownish, purple-ish gray body.

It’s pretty big, way bigger than other audio stuff I’m currently using. My daily driver stack – SMSL SU-9 and Topping A90 isn’t even half of the size of the reviewed Feliks Audio Euforia Evo. OTL means output transformerless, but it doesn’t mean that there are no transformers at all, there is one on the power supply stage and you can feel that it’s serious stuff, thanks to it, the amplifier weighs about 7 kg.

If the ridiculous weight and size don’t convince you, then remember that the vacuum tubes are also not very efficient. This means that they utilize lots of electric energy just to produce heat, I will skip how the tubes work, but you only need to know that to work some parts of it need to be hot, I mean literally these parts need to be red-hot. So if you have children, just keep the Feliks Audio Euforia Evo away from them.

Feliks Audio Euforia Review, photo of the front

Ok, so I’ve already mentioned that the reviewed Feliks Audio Euforia Evo, like any tube amplifier, is big, heavy, dangerous, and consumes kilowatts of electric energy, but the best part is that the tubes require some time to heat to the proper operating temperature. “Some time” means about 30 minutes, so before listening you can brew some coffee, watch an episode of your favorite series or clean up your apartment. As you can see, using the tube amp isn’t an easy thing. That’s kind of a commitment. The commitment that you want to spare some time just to make your listening session special, but about the magic and what the commitment gives you in return you will read in the next part of this review.

How does the Feliks Audio Euforia EVO sound?

The look of the device is important, and the experience and the way the user interacts with it are even more important, but at the end of the day, the sound is the thing that defines if the gear is good or not. Some people claim that good audio gear is the perfectly neutral one, and in that case, Feliks Audio Euforia Evo would be a bad amplifier, but we humans are a bit broken. Most people would pick seasoned and cured ham over the fresh meat and in terms of audio, distorted (of course in a proper way) sound is more pleasant.

Let’s start with the bass that is very dense, rich, and warm, but don’t get me wrong it’s far from being clumsy or boring. The amp perfectly pairs with headphones that have fast and punchy bass, but the smoother ones are welcome as well.

I didn’t test any headphones that wouldn’t gain in terms of the bass response when connected with Euforia Evo. The more bassy headphones like Campfire Vega 2020 (yeah, Euforia Evo can drive even some IEMs without bigger problems) sounded pretty well – the bass was smooth, but not too smooth and without overwhelming other frequencies.

While listening to Halayo by Duit the bass flows and it has great texture. Maybe it’s not as punchy as when played with some solid-state amplifiers, especially in this price range, but it doesn’t matter, because the “creaminess” makes the bass kinda magical and delightful.

The midrange is a place where the reviewed Feliks Audio Euforia Evo shines the most, anything you will plug into its output will reproduce the midrange in a magical way. It’s powerful, vivid, and lively. The timbre is very unique and analog, it causes any headphones to be extremely engaging. Maybe it could be a bit more pushed forward since many amplifiers do it way more, so the midrange is more intimate, but the warmth and richness provide that big dose of emotions that I don’t care about its minor flaw.

The way the reviewed amplifier reproduces vocals is also very unique. I used to listen to the vocal of Nick Cave in People Ain’t No Good many times with lots of different gear, but when played with Euforia Evo, his voice made me feel gooseflesh since I can’t remember when.

Acoustic instruments sound incredible as well and since I’m from Poland, Feliks Audio Euforia Evo is designed and made in Poland, so I just need to help myself in describing the sound with a song Chasing the Now by Polish cellist Dobrawa Czocher. The cello has an amazing full-bodied timbre, you can nearly feel the rough texture of this sound but at the same time, it has smoothness and warmness so the experience is charming.

The treble is the most colored part of the frequency response of the reviewed amplifier, but I can’t say it’s bad, to be honest, it’s again – beyond amazing. The way it’s tuned makes even the worst mastered songs with tones of sibilants and harshness in the top end sound pleasant. But don’t worry about details or the sparkle, it’s still present, but it’s served in a perfectly balanced way as all things should be.

Now the last and probably the best part of the reviewed Feliks Audio Euforia Evo – the soundstage. It’s wide and deep, with perfect positioning of sound sources. Apart from Feliks Audio Envy, I haven’t listened to any amplifier that would create such an exceptional soundstage. Everything is in the place you would expect.

As I’ve already mentioned in my previous reviews, To Be by Your Side by Nick Cave is the ultimate benchmark for soundstage reproduction, and usually, I’m writing that if I’m able to feel that I am surrounded by birds, the soundstage is more than satisfying. But when listening to it with Feliks Euforia Evo, I can easily pinpoint each bird flying around me, just let me emphasize it once more the resolution of the soundstage is purely EXCEPTIONAL.

What’s worth to mention, Feliks Audio Euforia Evo is also featured with a physical cross-feed switch. The cross-feed is a feature that partially mixes left and right channels together. Due to the lower separation of the channels, the soundstage is getting narrower, but the depth improves a lot, so you have two completely different characteristics of the soundstage shape in a single device. The resolution of sound sources is still on the top tier nonetheless the cross-feed is on or off.



Fostex TH-900 MK2

When thinking about good synergy with OTL amplifiers, most people would probably say dynamic driver headphones and Fostex TH-900 (priced at $1600) is a perfect representative of the family. It’s a closed-back headphone with a bio-cellulose dynamic driver and damn, that’s right – it pairs so well with reviewed Feliks Audio Euforia Evo.

TH-900 mk2 are known for their bassy tuning, the bass may overwhelm other frequency ranges and in addition, it’s a bit clumsy. But when paired with the Euforia amp, the bass becomes stiffer, and the dynamics are amazing. From pretty average in terms of sound quality the headphone becomes amazing, it discovers lots of texture and precision. I’ve decided to listen to Healing from the album Colure by Howling, but somehow I’ve just listened to the whole album… Twice… 

The midrange is ok, the amp makes it a bit warmer and adds a bit more texture, so it’s fine to listen to some acoustic instruments or vocals, but there are better options if you’re looking for headphones for that kind of music.

The treble of the TH-900 mk2 is a bit too harsh, but when powered with Feliks amp it’s getting more pleasant. The resolution is still on a very high level, but the tube warmth makes it a bit more “listener friendly”.

The soundstage is getting more layered with better resolution of the sound sources. The size is still not the best, but remember that Fostex TH-900 mk2 is a closed-back headphone, so expecting a tremendous soundstage would be at least slightly inappropriate.

Overall I think that’s a great setup for electronic music, as I mentioned, the album with Austrian-German electronics nearly hypnotized me. 

Fostex TH-909

In terms of drivers, Fostex TH-909 is a twin design with the TH-900, the only differences are that it’s an open-back headphone while the TH-900 is a closed-back one and it’s slightly more expensive, its price is $1799. So again quite expensive, dynamic, bio-cellulose driver headphone

The treble is getting slightly warmer but still very detailed. I’ve heard about a guy who modded the TH-909 to make it even more sparkly, he removed everything that was between his ears and the headphone – including earpads because that was the best way to listen to some niche Japanese music, but if you’re a more casual listener, then you probably won’t blame the change the amplifier introduces in this frequency range.

Another great thing is how the Feliks Euforia Evo improves the midrange – it’s getting more vivid and lively. The vocals are getting a more natural, analog timbre.

The bass is still weighted, I would say it’s getting tectonic. I loved how He’s The Pirate from Pirates of the Caribbean: The Curse of the Black Pearl soundtrack sounds with this kit. 

TH-909 has a pretty wide soundstage, and here comes the cross-feed. For example, I didn’t like how it changed the soundstage of TH-900, because it was getting a bit claustrophobic, so I enabled it once and didn’t do this anymore with it, but the open-back Fostex cans are a completely different thing. I loved how it improved the depth of the soundstage. I wish I could test how Sennheiser HD800 would improve with the Euforia Evo with enabled cross-feed, but for now, I need to satisfy myself with the Fostex.

Shortly speaking, if you’re a fan of orchestral music, then you should definitely test this pair. Otherwise, I think, there are more universal pairings, but still worth giving them a try.

HiFiMAN Arya Stealth

Guys from Feliks Audio told me that Eufora Evo can handle most headphones available currently in the market, and that means it should also handle planar magnetic driver headphones, which require watts of power at relatively low output impedance – that’s completely opposite to characteristic of typical OTL headphone amplifier.

HiFiMan Arya Stealth is an open-back, planar magnetic headphone priced at $2000. At that price you receive very technical-sounding headphones but with a dose of fun. Some people say that it’s a very good end-game headphone, but when I used to listen to it for the first time, I thought it was too harsh for me. The treble wanted to drill through my head, but it was connected to a bright-sounding source.

When connected to Euforia Evo, the HiFiMan headphone becomes extremely superb. The treble calms, but it’s still crispy and no details are lost, it just becomes pleasant to listen to. The midrange gets a bit more mass, it’s more lively, and finally, it isn’t too clinical, it becomes natural. And the bass – that sounds good no matter the source, typical for the planar headphones, goes very low, but it’s still fast and aggressive but with the reviewed amplifier, it gains on the impact.

To be honest I did some research before the review and one Redditor wrote that this is an awesome pairing and since I didn’t like Arya for the first time, I was a bit skeptical. But After the tubes warmed up I put on the headphone, and damn. I just wanted to listen to music, any genre, any release, I was gone. My curiosity about how another song will sound was tremendous, I just wanted to switch from one song to another but I wanted to listen to whole songs at the same time. 


Meze Liric

Meze Liric is a high-end, planar-magnetic, closed-back headphone, priced at $2000. When I listened to it I just fell in love, it’s not a headphone that will make you gather the shattered fragments from the floor, but it’s just fun to listen to them for hours, without tiredness, like all Meze headphones used to listen to – maybe on High-End Munich I will be able to listen to Rai Solo and Rai Penta, then it will be the whole lineup.

Let’s start this pairing description with the bass response. Liric has a natural bass with amazing texture and pretty good control but with a little lack of speed. When plugged into reviewed Feliks Audio Euforia Evo it’s still very analog, but unfortunately, the speed doesn’t improve. It also doesn’t decrease, but let’s say that there are better amplifiers that can improve this part of the frequency range. A good example can be a Ferrum OOR, another Polish construction, but it’s a solid state, so a completely different construction.

The midrange of the Liric is slightly recessed so it would be logical that when connected with the recessed midrange of Feliks Euforia Evo the result may be far from good, but you couldn’t be more wrong. The power of the midrange of Liric with the density and timbre of the amplifier makes the sound extremely appealing.

I think the most characteristic part of the Meze headphone sound is the treble. It’s very fast-forwarded, so a synergetic sound source is crucial to make the Liric treble not steal the whole show. And the character of Euforia Evo perfectly matches Liric’s. After pairing highs are relaxed, and way more pleasant to listen to, but still without a loss in detail resolution or texture, hard to imagine if there is a better source for Meze Liric to make the treble sound better.

The soundstage of the headphone is really impressive, especially when considering that it’s a closed-back headphone. After connecting to Feliks Euforia Evo, the soundstage is still amazing with slightly better resolution of sound sources, but that’s only a small step since Liric is great in terms of soundstage even with worse sources.

ZMF Atrium

Reviewed Feliks Audio Euforia Evo with ZMF headphjones

Last but definitely not least, one of the latest headphones from the ZMF lineup – Atrium. It’s a semi-open headphone with a bio-cellulose dynamic driver priced at about $2500. With 300 ohms of impedance measured at 1kHz, the headphone is pretty hard to drive, but Feliks Euforia Evo is the amplifier just made to be paired with this kind of headphone. I’ve never felt the reviewed amplifier doesn’t provide enough power to drive the Atrium.

The treble is smooth, but with a very agile presentation, I would say that the listener needs to get used to the presentation of the treble, because, for a couple of first songs, it’s a bit weird. But after some time, it just charms the listener.

The midrange is very analog and natural, well presented. Especially when plugged into Feliks Euforia it’s the most pushed-forward part of the sound signature. That’s why the most magic happens when listening to acoustic music. Tamacun by Rodrigo y Gabriela sounds just great played with the described pair – full-bodied and incredibly engaging.

The bass is very linear, for me even with Euforia it lacks a bit of impact and slam. It’s a bit too relaxed, but yet again, after a couple of songs when you get used to the signature, it’s getting interesting.

The soundstage is pretty wide and deep, but since ZMF Atrium is a semi-open-back headphone, it won’t be as wide and deep as when compared to previously described pairings. Euforia improves the width a bit, but anyways I’ve already listened to more spacious cans in this price range.

I think it’s a perfect pair for a person who wants to sit in an armchair with a glass of good whisky and just chill with music. Without focusing on technicalities, just play the music and let the magic happen.

Feliks Audio Euforia EVO review — summary

Feliks Audio Euforia Evo isn’t only a headphone amplifier, it’s a statement – the statement that the sound is the most important for you. That’s not the best-measuring amp in its price range, but it doesn’t matter, what’s really important is that it provides amazing timbre and enough power to drive most headphones available in the market. For me, that’s more than enough to highly recommend it if you’re looking for a tube amplifier that will easily drive most (or probably even all) of your headphones. 

There is only one problem with the Feliks Audio Euforia Evo – due to tube technology limitations, I wouldn’t pick it as a first amplifier in my collection, but if you already have an amplifier that is your daily driver and now you’re on the hunt for something special, that will put your listening experience on a higher level, then you should definitely give it a try, or just buy it without thinking because it’s purely awesome.

Purely awesome to the point, where I just ended up buying the review sample loaned to us from Feliks Audio. There was no way that I’m giving that amplifier back.

Wildly recommended. 

Big thanks to Feliks Audio for loaning us the Euforia EVO 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.