Woo WA5-LE vs Feliks Euforia AE - Two high-end tube amps fight it out to claim their place as king of the (audio rack) hill.
This will be the primary review, with some follow-ups as questions are asked and tubes are rolled. The amp I prefer less will eventually be sent off to another home, but I’ll keep both for some weeks so that members of the community can ask for specific comparisons or tests.
I will be concentrating on both amps with their stock tubes for this review. I do have a few upgrades for each, and I’ll make notes on them later, but given the nearly infinite permutations that can be had with tube rolling, and a not-infinite tube budget for me, I feel it’s most fair to start with what the manufacturer would send you.
Some months ago, I decided to wade into the world of tube amps to see what this “tube magic” was all about. After weeks of reading and carefully watching buy/sell forums, I pulled the trigger on a Woo WA5-LE. Days ago, I came across a Feliks Euforia AE, which I have generally considered one of the primary competitors to the Woo, given both cost about the same, and both supposedly play nice with low-ish impedance headphones (like my Utopias). The beauty of buying used is that you can try things out with minimal loss, and I wanted my comparisons to potentially help others on their journey. I will try to be as objective as possible about specific qualities of the sound, but always tread carefully around “better” or “worse”. I would call my approach scientific-ish. Same tracks, in close proximity time-wise, but I simply don’t have a setup where I can have both amps turned on at the same time and quickly flip between the two, and I don’t have a measurement rig to volume match. Still, I feel that the perceived differences are clear enough to me that I can give a sound (hee hee - see what I did there?) comparison.
Power: PS Audio Stellar Power Plant 3 with meaningfully upgraded power cords throughout
Source: Custom NUC running Roon ROCK with access to Qobuz, Tidal, and some locally stored hi-res files
DAC: Chord Hugo 2
Headphones: Focal Utopia through upgraded single-ended cable
Primary Test Playlist
(Artist - Album - Track)
Doug MacLeod - There’s a Time - Black Nights
AC/DC - Back in Black - Back in Black
PaTRAM Institute Male Choir - Teach Me Thy Statutes - Blessed Is the Man
King’s Singers - Gold - Die Nacht
Yo-Yo Ma - Six Evolutions: Back Cello Suites - Suite No. 2 - Prelude
Trifonov / Philly Ochestra / Nezet-Seguin - Rachmaninov: Piano Concertos 2, 4 - Piano Concert No 2 - 1. Moderato (1st movement)
Bamberger Symphoniker - Mahler: Symphony No. 9 in D Major (Live) - 2nd Movement
Yosi Horikawa - Wandering - Letter
Infected Mushroom - Army of Mushrooms - The Rat
Coryells - Chesky 30th Anniversary Collection: Complete Set - Love and Happiness
Jen Chapin - Chesky 30th Anniversary Collection: Complete Set - You Haven’t Done Nothin’
The New Appalachians - From the Mountaintop - Make Me Down a Pallet on Your Floor
Lorde - Pure Heroine - Royals
Beyonce - Partition - Partition
Beatles - Rubber Soul (Remastered) - Norweigian Wood
Stevie Wonder - Songs in the Key of Life - Sir Duke
Van Halen - 1984 - Hot for Teacher
Nickel Creek - Nickel Creek - The Lighthouse’s Tale
Michael Wollny Trio - Weltentraum - In Heaven
The Fairfield Four - Standing in the Safety Zone - Children Go Where I Send Thee
Feliks Euforia Anniversary Edition
The Anniversary Edition is not posted on the Feliks Audio home page, but apparently can still be had by special request
Read, Set, FIGHT!!!
I started by listening to my test playlist directly through my Hugo 2 as a “palette cleanser”. That acted as my baseline against which I could judge relative changes in detail, speed, and instrument separation. To help you all level-set to my subjective preferences, I want to note that I love how my Utopia sound directly through the Hugo 2, and am not of the opinion that the Utopia need a tube amp. I chose the Utopia because I love the speed and the detail, and don’t find them harsh or sharp through most equipment. That said, a great amp can definitely provide synergies, and I have found this to be a really fun and rewarding exercise.
Category 1: Detail Retrieval
Winner: Woo WA5-LE
Both amps had a noticeable drop off in detail from plugging straight into the Hugo 2, but the way in which that manifested itself was a bit different. Both had what I would describe as slight muffling, but the Euforia felt like it also had what I can best describe as “fuzziness”. Put another way, the Woo might have put the music on the other side of a big quilt that was hung up in a room, where you could mostly hear the detail, but it was just a smidge less pronounced, whereas the Euforia turns that quilt into a thick fleece blanket. Neither sounded particularly “liquid”, which is something I’ve experienced with other amp combinations. I would, however, give a slight edge to the Euforia in bass detail, as the Woo did have a bit of bass bloom that wasn’t as evident in the Euforia. Still, considering detail overall, I felt the Woo was the winner here.
Category 2: Speed
Winner: Feliks Euforia AE
I felt that both amps had pretty good response in terms of the attack (transients) of notes, but the Woo had a slightly longer decay, resulting in less crisp stops. This was particularly evident on electronic music (which isn’t really ideal to listen to on tubes, in my opinion, but worthwhile to test speed), and for any faster drum sections (like the intro to Too Hot for Teacher by Van Halen). I’d like to note that the “fuzziness” I mentioned in the detail retrieval section is still a factor in the Euforia’s transients, so while still fast, they don’t sound as clear or close to the Hugo 2 as on the Woo. While I think the detail/speed tradeoff is important to consider here, if we’re talking purely speed, I have to tip the contest to the Euforia.
Category 3: Sound Stage and Instrument Separation
Winner: Tie / Personal Preference
For this category, I have a hard time choosing a winner, and have to just say that they’re different. Both amps put good distance between the instruments, and the sound stage for both is perceived as deeper than on the Hugo 2 alone. I couldn’t pick out a clear winner on depth. The major difference is in what is going on between the instruments. I perceived that the Woo puts some air in between the instruments, and I felt like that I could pick up both the instruments in their pockets, as well as the space between them - like they’re all playing in the same physical space. The Euforia had very distinct pockets of instruments with about as much distance, but noticeably less air between them, which is closer to the Hugo 2, by itself. I personally like the more open feeling of the Woo with the airy space in between instruments, but I want to be careful to not inject my personal preference there, as some may very much like the more distinct pockets (or blobs) of sound in the Euforia.
Category 4: Blackness of Background
This one is the toughest to pin down, as there can be differences in individual tubes or amp builds that can swing the result on a case-by-case basis. Both amps are quiet, but certainly not dead silent. At a quarter turn on the volume knob (no music), the Woo is a hair quieter.
Interestingly, the Euforia had a pronounced hum between 1 o’clock and 3 o’clock on the knob, that mostly went away as I turned past it to max volume. That indicates to me that there may be a small issue with my volume pot. In any case, the Euforia was quieter at max volume. (Edit: This seemed to go away with time / tube rolling, so may have just been how I inserted a tube). Without getting into details, changing tubes has had a huge effect here (on both amps), so I don’t think there was enough in the stock setup either way to declare a winner.
Category 4: Build
Winner: Tie / Personal Preference
Both awesome, but different. They are both heavy, and fairly tank-ish in build quality. The Euforia is more refined, with clean lines and a glossy finish. The volume knob is super smooth. The Woo is a beast, with rougher edges, but also solid as a rock, and looks more like something out of a 60’s space movie. I personally like the Woo for it’s wow-factor, but the more compact and sleek Euforia may very well be preferred by some.
And the winner, considering stock tubes only, is…
… you ready for this?..
The Hugo 2
“WAIT WHAT!? WHAT IS THIS GARBAGE!? I thought you were going to help me pick an amp…”
Okay, okay, hold on. Catch your breath. Both amps have their merits with stock tubes, but this is where I get to be subjective. I personally wouldn’t recommend buying either amp unless you are willing to invest a meaningful amount ($500+) in tube upgrades. I’ll dive into that in further commentary in follow-up posts, but long story short, the modest shortcomings of the stock-tube versions were enough for me to feel I’d rather just go straight out of the Hugo 2. Otherwise, why bother with equipment as capable as the Utopia and Hugo 2? I might consider the stock-tube Euforia if (1) I felt that the Utopia (or similar) was a bit too harsh and needed some “warming up” (which I don’t), or (2) to help take the edge off of sub-par recordings, which the amp actually does accomplish nicely. Basically, the Euforia can wrap your music in a fuzzy (but very fast) blanket, and that’s actually perfect for some use-cases. After my formal review listening I did to back to recordings I don’t love out of the Hugo 2 (with or without the Woo), and ended up being very satisfied with them out of the Euforia. The stock Woo, I would prefer only on a limited set of recordings - even more limited than the Euforia. However, I wouldn’t personally spend this kind of money on an amp that didn’t improve things meaningfully for my primary listening.
So what’s next? Well, some tube rolling. It won’t be conclusive, because my tube access is limited, but my conclusions with new tubes change meaningfully. More on that in a day or two…