Kenzie Encore Headphone Amplifier Review by InnerFidelity

I must admit, this review is a little different for me. I generally try to focus on lower or mid-priced gear that represents a value proposition — essentially, things that would interest other 23 year old freelancers on strict budgets — so I was a little trepidatious before my first call with ampsandsound founder Justin Weber, as a $2,000 USD tube amplifier is decidedly not what I would consider within my budget. Weber spoke very thoughtfully about his attempts to keep costs down and consider ergonomics for those without the luxury of equipment racks and gobs of space or funds. "The idea was that you could fit it on a bookshelf if you needed to," said Weber.

Photos courtesy of ampsandsound. A quick survey of other small manufacturers of tube headphone amps revealed that many are similarly priced or sometimes even more expensive than ampsandsound Kenzie offerings. Weber explained the Kenzie Encore as an attempt to tailor the design and feature set to the personal-audio community while improving sound quality over the base Kenzie. It is designed as a classic Darling circuit topology using one 12SL7 input tube and two 1626 output tubes. Input impedance is a nominal 10K ohms and there is a choice of output impedances, with each Encore allowing two different impedance outputs ranging from eight all the way up to 600. I opted for 32-Ohm and 300-Ohm outputs and skipped the Input Transformer and Upgraded Capacitor options, which add $450 USD and $100 USD to the price respectively. I was tickled when Weber told me that while the upgrades do make a difference, he recommends most people, "skip the caps, buy music." Definitely speaking my language. The amp itself is rather industrial looking to my eyes: two single-ended 6.3mm jacks on the front, three tubes in the middle surrounded by four transformers and one pair each of inputs and pre-amp outputs on the back. The build quality is nice and very sturdy, the wood is nicely finished, the metal plate is thick and engraved. The transformers add a ton of weight on one side, but everything fits very securely on the chassis without any wobble or looseness and it seems to support itself well. The ALPS volume pot moves smoothly and draws no overt attention to itself. Tube installation and removal is easy, and is not noticeably tight or loose. From the outside the Kenzie is a nicely assembled piece of gear, understated and totally functional.

The amp specs are a bit shy on output, about 200 milliWatts at 32-Ohms at 1kHz. As long as an amplifier provides plenty of current and drive, I’m not fussy about what the specifications say. I will make a note here that my general preference is for a fairly balanced, somewhat drier solid-state sound, with plenty of punch, and with a preference for a slight warm tilt over a slight bright tilt — a byproduct of working as a musician and mastering engineer. I am open to and have purchased and used a wide variety of sound palettes and amplifier topologies however and consider myself open to a variety of presentations. Enough details though, let’s dive into the sound. I’ll be clear about this upfront: the Kenzie Encore is not a neutral amplifier.

However, it is most certainly a high-end one. The tonal balance is quite midrange-forward, with bass that is softer and lower in balance and somewhat colored in the presence region and rolled off but sparkly with saturated highs. Unlike other tube amplifiers I have listened to, the coloration of the Kenzie was most obvious at the transition points between these three bands though. The midrange is actually quite clear and dynamic with snappy transient response. I was surprised by just how dynamic the Kenzie was, it never steers into overly rich or warm territory and as a result has a startling sense of stage depth and transparency — the "3D" effect as some people like to call it. In fact, because of the rather subdued bass level, I found the Kenzie on certain headphones was a bit too dynamic for tastes, occasionally sounding a bit aggressive in sensitive presence and treble regions for my tastes. I know some people enjoy this very sharp transient sound however, so while not to my preference, it is not necessarily a downside. The treble too has a really remarkable sense of air and presents music very naturally, giving it even a little soundstage enhancement. I felt that this effect was generally very pleasing, but it sometimes made aggressive or more compressed recordings sound a little deeper or airier than they really were. This is most likely an upside for most, and I will admit it made for pleasant listening on some poorly-produced recordings. However there were other recordings that did not fare so well. I found that some recordings I have that are a little dark had me reaching for the volume knob, only to find the midrange much too prominent, bordering on shouty. A few examples of recordings I used, to illustrate these characteristics were Robert Randolph and the Family Band’s "Ain’t Nothing Wrong With That." This is a song with huge dynamic punch. The recording is heavily compressed, though not in a brickwall, chop off the transient peaks way, but in a tight, punchy rock and roll way, with some nice saturation and sparkle in the upper frequencies. The beauty and danger of this recording is that very punch — the midrange and upper-midrange energy between 500-3000Hz is enormous and with midrange-happy equipment quickly becomes shouty. Unfortunately, this was the case with the Kenzie, which added midrange and treble sparkle and saturation, but emphasized the aggressive midrange of the song too much. I found this a fatiguing combination. Unlike some tube amps which soften transients, the Kenzie makes them appear more aggressive in the midrange.I ran into similar problems with other modern rock and hip-hop tunes, such as Prince’s "FunkNRoll," which lacked the 28-32Hz bass fundamentals and sounded harsh in the midrange. On the other hand, the music that played to the Kenzie’s strengths sounded phenomenal — older recordings or those with more muted transient energy were excellent. Melody Gardot’s “Morning Sun” and "Once I Was Loved" are mixed with a huge amount of presence in the vocal part. The overall album has an interesting, thick and dark sound to it however and most of the punchiness is in the 200Hz range. The Kenzie added a layer of 3D sound-staging depth and midrange and treble sweetness that colored the darkness of the album in a very pleasing way. The vocals went from intimate to spine-tingling in their transient clarity. In this case the Kenzie’s chosen coloration worked wonders — accentuating just the right bands of warmth and clarity to make the music spring to life. I think the combination of my heavily-modded HD800 with the Kenzie is my favorite presentation of this album on headphones I’ve yet heard. Other music that worked well was folk music, and some classical. The Goat Rodeo sessions between Yo-Yo Ma, Chris Thile, Edgar Meyer and Stuart Duncan is an album of bluegrass and classical crossover, with plenty of string plucking and a wonderful clarity and ambience. As it is an entirely a string band with some vocals, there’s little in the way of extreme-bass content and the Kenzie presented the music with a pleasing combination of warmth and clarity. Likewise the Carolina Chocolate Drops sometimes bright cover of "Hit ‘em Up Style." Orchestral music from the likes of Austin Wintory’s Journey Soundtrack and Tellarc’s famous Jupiter rendition by Andre Previn, had sound-staging and midrange sweetness and warmth that played well to the Kenzie’s upper-midrange coloration in just the right ways. By emphasizing that frequency band, and transients, the Kenzie took the music to a higher level of tactility, perceived transparency and depth. Weber also suggested I would enjoy the preamp capabilities of the Kenzie, so I tested it in that capacity and in this use it behaves much like what you might expect of an all-tube gain stage. The sound is quite warm, with plenty of soundstage and a little softening and more roll off at frequency extremes than when driving headphones. Speaking of headphones, I found the Kenzie a capable match for pretty much anything I plugged into it. I had far more gain and volume pot play than I would ever need with the HD800, Mr. Speakers Aeon, ZMF Ori and Beyerdynamic DT880 just to name a few. In terms of ideal pairings, I feel that darker headphones like ZMF make for a response that is too colored for my tastes, although I know many enjoy using tube amps with these headphones. The DT880 benefitted a bit form the somewhat forward midrange, helping to enhance their sense of depth in that range, while taming a little of this headphones brightness in the 8-12kHz region. The Mr. Speakers Aeon had tremendous presence, though I found it occasionally harsh. This was a pairing that only worked sometimes for me, but when it did work it was phenomenal, the Kenzie helping to open up the slightly flat and clinical soundstage of the Aeons, and giving the illusion of greater detail and a slightly smoother frequency response. I did the majority of my listening on my modified HD800 and found these to also be an excellent match for the Kenzie. The HD800 can be somewhat reserved in the upper-mids, even after modification, and the Kenzie helped bring some extra transient energy and presence, which worked well in my opinion. As a side note, between the two different output taps, I preferred the lower impedance 32-Ohm tap on all the headphones I tried with this amplifier. The 300-Ohm tap seemed overly colored and muddy, even on higher-impedance headphones.

So there it is, the Kenzie is exuberant and somewhat forward in the midrange, with sharply defined transients, depth and a sort of sparkly-saturated upper midrange, and somewhat rolled off or at least subdued extreme bass and treble bands. If your music tends toward older, duller recordings, or music with softer transient energy, the Kenzie brings a level of midrange magic and harmonic euphony that can make appropriately-matched recordings a joy to listen to. If my music choices consisted solely of bluegrass, old rock, quieter orchestral recording and the like, I would not hesitate to see this amplifier as an endgame purchase. While my personal tastes are for a less colored, less aggressive presentation to the music, the Kenzie is an excellent amplifier. My philosophy on gear choice outside the studio setting is to pick things that match your music and make you happy. I certainly had many evenings of listening pleasure with the Kenzie, and as I surveyed other options in the high-end tube amplifier market, I had an interesting realization. While there are less expensive tube amplifiers, the Kenzie really plays with high-end tube amplifiers that I’ve heard from the likes of Eddie Current, DNA. However most of those amplifiers are quite a bit more expensive and often very difficult to obtain, with long wait lists and some out of production completely. With this in mind, the level of quality on offer here is quite high. At $2,000 USD MSRP I don’t believe I can call it affordable, but I will say I think it is appropriately priced in relation to the rest of the market, and a fair bit less than some of the excellent competing amplifiers I mentioned. On a pretty subjective note, I’ve listened to some popular $1,000 USD~$2,000 USD tube amplifiers out there and been unimpressed by the value proposition. Many are nice, few are as nice as I would hope for the price. With the Kenzie I never got that feeling, during my entire time with the product, I felt everything from build quality to sound quality was above average. Even though aspects of the amp do not fit my preferences, I feel these are the result of conscious design and manufacturing choices, and not deficiencies or quality issues. The Kenzie gets a thumbs up from me.

Recommended for anyone looking for an endgame tube amp with some midrange magic and transient mojo. Original review