Ampsandsound Kenzie Ovation Rev 2 Headphone Amplifier: Review

The Head-Fi revolution over the past decade played a huge part in turning a cottage industry into a global one with some heavy hitters. The market for high-end audio headphones and amplifiers is now a substantial one with dozens of manufacturers scatted across the globe building really unique products in workshops that find their way into some of the world’s best audio dealers and luxury retailers.

California-based, ampsandsound, has been a love affair between Justin Weber and the community for many years and it would not be overstating it to suggest that his expanded lineup of headphone amplifiers, power amplifiers, SUTs, and accessories are some of the best available.

EIC Ian White and I have both been fortunate to have spent considerable time with the original Kenzie, Bigger Ben, Mogwai, and Agartha amplifiers, which we both agree are very impressive products.

Justin Weber is a craftsman who puts an incredible number of hours into each amplifier which is handmade; he also has a full-time job and family so his commitment to each product sold is rather commendable.

If you take the top plate off the Kenzie Ovation Rev 2, the attention to detail in the construction and wiring is rather evident; Weber is somewhat obsessive when it comes to how his finished products look (internally and externally) and it explains why they last and have proven to be very reliable components.

How I found ampsandsound is an unlikely story; when I first started reviewing audio components and exploring the personal audio category, a dealer selected me to be part of listening tour.

Todd The Vinyl Junkie, selected me for a 10-day review trial with the original Kenzie Headphone Amplifier. The original model was more “affordable” than the current Ovation Rev 2 and while we can certainly blame inflation and supply chain issues for the price increases — $4,200 is still a lot of money for a headphone amplifier.

The Kenzie proved to be a very impressive listening experience and being part of the tour, opened my eyes to the rather welcoming nature of the Head-Fi community; which has its jerks like any other hobby but most members are more than willing to answer questions or even get together for a listening session.

The high-end headphone side of the industry has taken the long road to get to this juncture and the collective family deserves a lot of the credit for the meetings, CanJams, and road show tours to grow the audience and community.

Have prices escalated too quickly for a lot of people? There is some truth to that but manufacturers have to make a living at this and the cottage industry had to make some financial and marketing decisions if it wanted to grow beyond mere enthusiasts.

The pandemic was a horrible two years, but a great opportunity for the category to grow with tens of millions of potential global customers stuck and working from home.

The community certainly rallied and companies like ampsandsound, iFi, HiFiMAN, and Grado Labs have grown exponentially even through all of the chaos; supply chain issues have been the one substantial hurdle for a lot of companies and Weber has not been immune to it.

The bespoke nature of each design and the quantities that we are taking about means that Weber isn’t the most important customer for parts suppliers who need to worry more about losing manufacturers who sell thousands of components each year, and that has driven up wait times and costs.

The Skinny

Our sponsorship and participation at T.H.E. Show in Long Beach, afforded us the opportunity to demonstrate headphones and portable audio equipment from a wide range of manufacturers.

It was also my first Hi-Fi show and being asked to run the eCoustics booth meant that I had less time to walk around and listen.

It was a matter of blind luck that the ampsandsound booth was directly next to our table and it offered me the chance to finally meet Justin Weber in person and listen to the rest of his products.

The Kenzie Ovation Rev 2 Headphone Amplifier is a rather popular product right now and the review sample needed to be returned for the CanJam SoCal Show which happens this month; Brian Mitchell will have coverage from the show and it is shaping up to be one of the largest of its kind.

Because of the time constraints, we pushed aside other reviews so that I could maximize the seven days with the amplifier. After 75 hours of listening time and putting the Kenzie Ovation Rev 2 through the wringer with the Astell&Kern KANN MAX, Cayin n6ii MK2, and Shanling M6 Pro DAPs, it was rather disheartening to have to send it back.

Headphones used included the Kennerton Rögnir, Audeze LCD-3, Kennerton Magni, and Monoprice Monolith AMT — which you can read about later this week. A very interesting attempt by Monoprice to take on some big players in the category.

Tubes, Igor. Find Me Some Tubes

2021 was a challenging year for ampsandsound (and many other companies) because it had to take a more realistic approach to its designs and how supply chain issues would impact manufacturing. The supply of vacuum tubes is an issue facing all high-end audio manufacturers that use them in their products and the octal input tubes used in the original Kenzie were no longer very practical and also somewhat noisy.

The problem is that the tube was part of the secret sauce that makes the Kenzie such a sweet, and colorful sounding amplifier. Others will describe it as a coloration that makes the Kenzie less than accurate sounding as far as headphone amplifiers are concerned.

They would both be right. And that reality has made the Kenzie both a success and somewhat controversial.

The changes required a new setup and the company has opted for a 9-pin front end, running 1626 VT-137 Hytron Corporation input tubes. These tubes are readily available, and not exactly going to empty your wallet.

One benefit is a reduction in the noise floor, which was a rather legitimate criticism of the original design. 12AX7 tubes are also not the hardest to find, even if they have become more expensive. NOS versions (Weber is a tube roller) are not exactly cheap and we stuck with the supplied tubes for the review.

There is trickle down technology in play here with the new Kenzie Ovation Rev 2, those familiar with the Bigger Ben and Suolo Mono Amplifiers will notice that Weber went “bigger” with almost everything in the new design. Bigger doesn’t necessarily mean better but these are not superficial changes to the older model.

Everything from the PS capacitors, choke filters, and output transformers has been changed. The output transformers have twice as much capacity as the older ones and while they do look a lot like the transformers being used on the Bigger Bens, they are specifically designed for the Kenzie’s lower output power.

A larger core does allow for 5 different impedance settings; making the Kenzie Ovation Rev 2 more versatile in regard to the types of headphones that you can use. The 8 and 16 ohms taps are fine for high sensitivity planar headphones, and the 32 ohms taps work well with low impedance orthodynamic headphones.

Audeze planar magnetic headphones worked well at 100 ohms, and the 300 ohms tap lets one enjoy harder to drive headphones from Sennheiser and ZMF; ampsandsound already makes a special headphone amplifier for ZMF headphones and the Kenzie has the ability to drive them well.

The ampsandsound Kenzie Ovation Rev 2 is the antithesis of the modern desktop headphone amplifier in a number of ways; there is no DAC, phono preamp, remote control, support for MQA or Bluetooth.

The hardwood chassis is 15.75″ W x 9.75″H and it is not an amplifier to carry around with one hand.

Supplied Tubes: 

• Input tube: 5751 or 12AX7
• Output tubes: 1626 or VT-137
• Cathode Bias/automatic bias allows for easy tube changes without adjustment.

Specifications:

• Input impedance is 10K ohm with alps pot
• Input Sensitivity 1V for full power out.
• Frequency bandwidth 8Hz -1db to 18kHz -2db full power
• 8 ohm power: 500mWatts RMS @ 1khz
• Noise on 8 ohm tapp @ 400uV
• 32 ohm power: 400mWatts RMS @ 1khz
• Noise on 32 ohm tapp @ 530uV
• 300 ohm power: 480mWatts RMS @ 1khz
• Noise on 300 ohm tapp @ 540uV

Sound

As we were finishing up our review of the Astell&Kern KANN MAX DAP, the Kenzie Ovation Rev 2 arrived and it made logical sense to use the Korean digital player as our primary listening device.

The KANN MAX is a superb sounding DAP, but it does not offer the warm tonal balance that I prefer from my own DAP’s. It is certainly a matter of personal preference and does not take away from its superb resolution, detail, and transparency.

Once connected to the Kenzie Ovation, the A&K DAP sounded like a different device and that was rather consistent with almost every headphone in my collection; the Kennerton Rögnir (32 ohms) had greater presence and the resolution, spaciousness, and tonal balance were spot on.

There was certainly enough clarity and detail, but it was the presence and midrange color that absolutely floored me. Vocalists had so much texture and body, it was almost criminal to take the headphones off.

The Kenzie Ovation also gave the Rögnir more impact in the low end; which might surprise those who own and listen to the headphone and disagree that the Kennerton is lacking in that department. The more I listened with the ampsandsound amplifier in the signal path, the more I realized that the headphones could use some additional impact and definition in the bass.

This trio emphasized the strengths of all three components, but it was the Kenzie Ovation that really brought it all together. The Kennerton is a very underrated headphone that really shines with better source equipment and amplification.

When you are spending almost $9,000 USD on a desktop headphone system — it better be a state-of-the-art presentation of music with a lot more than just low end prowess and a warm sounding midrange.

Synergy certainly matters and this trio utterly blew my mind with the level of detail, presence, soundstage depth and width, and transparency.

Switching to the Cayin N6ii MK2 DAP, the sound took on another level of midrange warmth and overall richness. I prefer that to a more neutral sounding presentation, but I would agree that it is not for every listener.

The Kennerton and Audeze LCD-3 really opened up driven by the Kenzie Ovation; greater mid bass impact, more natural sounding brass instruments, and a lot more presence.

Could the combination cross the line and come across as too smooth or warm sounding? There is certainly the risk of that because the headphones already lean that way, but the Kenzie Ovation Rev 2 is not as warm sounding as its predecessor which I think is a positive.

It certainly sounds more transparent and detailed regardless of the source, and the top end detail has more airiness to it if the headphones can showcase it.

The Audeze LCD-3 is my favorite open-back planar headphone, but it does not always sound as resolving or open with some DACs and headphone amplifiers. Headphones are very finicky and even the best models can sound very average if the source and amplification are a poor match. Are loudspeakers any different?

The Kenzie Ovation Rev 2 just meshes so well with these headphones that one finds themselves transported into the moment; the clarity, spaciousness, and presence listening to jazz is rather sublime — which is probably not the best word for it but you just want to sit back, pour yourself a drink, and listen.

The LCD-3 with the right amplifier can present music with a much wider and deeper soundstage, but the Kenzie Ovation never exaggerated it on any track and that was rather consistent with most genres of music.

The added depth and almost holographic presentation with better recordings made me lose myself in the music and just continue listening for hours. That’s the sign of a very special component — one that helps recreate a moment in time between musicians in a studio or in some tiny club with a smattering of listeners in attendance.

Switching to Pinetop Perkins, I was immediately transported to a small, dingy Chicago blues club, where the tables still smell from the alcohol from the previous show and the decay of the piano notes linger just long enough in the air to make you sit slightly forward and marvel at the playing.

That’s one of the strongest attributes of the Kenzie Ovation; the manner in which it can jump from one genre of music to the other and never lose a beat.

Listening to Jeff Beck’s “Hammerhead,” the Kenzie Ovation presents all of the intentional distortion without adding any additional emphasis or stripping away its energy and intent.

The Campfire Audio Cascade is a very underrated headphone that does not have a huge following; something that is a great pity because it delivers some of the best bass response of any headphone available. Does it offer the resolution or clarity of the other aforementioned headphones? Not even remotely.

But can they deliver the ferocity and impact of Led Zeppelin or Jeff Beck and keep their composure?

The Cascade requires a degree of control to really showcase what it can do and the Kenzie Ovation has the ability to do that and elevate these headphones to another level of performance.

Conclusion

The ampsandsound Kenzie Ovation Rev 2 is a superb headphone amplifier that is worth every cent of its asking price just for the sound quality alone.

Does the amplifier need more input options? Ampsandsound could follow the trend and include a USB DAC option, but I think that would take away from the purity of the signal path and complicate things too much. It would also probably add $500 to $1,000 USD to the price which would be pressing its luck in a very competitive market.

The supplied tubes are selected by Weber and they work as advertised. Can you tube roll with the amplifier and spend hundreds of additional dollars on NOS tubes that will certainly have an impact on the sound quality and presentation?

You can certainly do that but it probably makes more sense to stick with the stock tubes for awhile and try as many headphones and sources as you can before changing something that might not require a change.

Trust the designer with what comes in the packaging. He didn’t just pick them randomly from a mixed box of tubes and pray that they work. Considering the scarcity and demand right now — save your money.

The industrial design is the right mix of wood and iron and the glow of the tubes is very seductive when your turn the lights down low.

Is it time to begin saving?

Indeed it is.

The ampsandsound Kenzie Ovation Rev 2 will one day be considered a piece of American Hi-Fi history worth overpaying for.

Where to buy: $4,200 at ampsandsound.com

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