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Audio Swiss Army Knife: Manley Labs Absolute Headphone Amplifier

01-04-2020 | By Al Chieng | Issue 107

This review took a little longer than I thought. I originally found out about this amp from my colleague Robert Levi, and could not resist sending EveAnna Manley an email to see if I could procure a review model. She was more than willing to send it out with the 250 monoblocks that I also requested, and in short order everything arrived.


Manley Labs really did a great job in packing this amp safely. Double boxed and having foam in all the right places, it was just a matter of lifting this amp into position. The tubes were already seated and protected in a foam shroud, which I obviously removed before powering this baby up. Manley made this amp ready to rock with NOS RCA tubes, power cord, and operating instructions.

Manley Labs Absolute Headphone Amplifier


I had seen this amp in pictures and several YouTube videos, but I was not prepared by how unique it looks in real life. First of all, it has a very solidly built chassis that is slim and slightly tall. Fit and finish is impeccable, as I have come to expect from Manley, with burl walnut veneer and copper colored metal trim in all the right places. The choice of materials is clearly something unique, as it blends the old world charm of warm wood with the modern feel of metal accents, smoked acrylic, and that satisfying tube glow. The semitransparent acrylic pieces allow you to view the circuit boards and led lights in a playful high tech sort of way, complete with a white led that crowns the Manley Labs logo on the top of the amp. The knobs are all color matched copper with a prominent volume wheel. Out back, the amp is ready to play with multiple hookups to turn the headphone amp into a preamp if need be, as well as balanced and single ended hookups for your headphones. The shape lends itself to headphones draped over the back half. Kudos to the design team for both its striking looks and some practicality to display both amp and headphones together.

Manley Labs Absolute Headphone Amplifier


I loved the brief explanation of the controls found on the back of the amp, to let the user know without the manual what they can do with this Swiss army knife. The power button is found on the back of the unit and once powered on a soft start function is enabled, properly powering up the system and letting the tubes ease into operation. Up front of the amp is where the fun starts. Detailed specs can be found on the website, so I will just stick to some of the highlights. The tubes, like I mentioned, are NOS RCAs that consists of two 12AX7 and four 6AQ5A. They were pretty quiet throughout my listening, and are tubes that replacements could be commonly found ready for you tube rollers out there. As the website states, the amp has fifteen independent controls available. Simple and intuitive, I found that I could use them to fine tune a particular need, or could leave it all basically alone and let the amp do what it needed. The flexibility was amazing, and contains helpful features like a mono button, negative feedback control, single-ended/push-pull modes, and a sweet stepped actuator for volume. All this can be done on the fly, making this amp ready for all different kinds of musical and gear changes without a single hiccup or power down. As a side note, this amp did respond to some tweaks, like different tubes and cables so if you are into that, enjoy.

Listening impressions

The all-important test is how this thing sounds, and for the most part this amp delivers on so many levels. I switched between multiple sets of headphones, such as Audeze LCD 3, XC, EL-8, Grado customs, and even some IEMs just to see what it would be like. I settled mainly with my trusty LCD 3s, but rest assured that this amp can handle many different headphones with aplomb (varying the impedance allows for multiple headphones to be compatible). Listening to Hi Res digital tracks for this review, I cued up the song "Chitlins and Gefiltefish" from Christain McBride featuring Gina Gershon. The playful song tests the ability of the amp to produce human voice, pace, and reproducing the bass. I enjoyed this track in push pull mode at 10dB negative feedback to give the bass a plucky deep sound coupled with a hop and bounce to induce the prerequisite toe tapping on my part. The recording session was brought to life, and the joy of creating music together was reproduced in great detail without ruining the overall improvising and pace. The second track was Amy Winehouse's "You Know I'm No Good." That soulful voice was never lost in this quintessential Winehouse track. Winehouse is in fully fleshed form. The back beat with the bass track and melodic instruments was well rendered in the background. Switching to single ended mode, and turning down the negative feedback, I put on an old but new track in Jennifer Hudson's "Memory," from the newly released Cats Motion Picture Soundtrack. Although the film itself has been getting mixed reviews to say the least, the song and Hudson's voice is beautiful and raw with emotion. The amp in single-ended mode rendered her voice with intimacy and a hint of added warmth left out of push pull mode. The amp was able to highlight her range, and her voice was free of semblance and had both the power and delicacy. The orchestra was well placed, coherent, and produced quite a large soundstage. Push pull on this track lost some of the warmth, but gave better depth and width. This track showed many of the strengths of this amp, and the way you could tailor it to focus on particular things you enjoyed about a performance. The last track I used was "Bad Guy" from Billie Eilish's debut album When We All Fall Asleep, Where Do We Go? The mix of this particular song is intoxicating, weaving a great bass line (beat) and her electronically altered vocals to paint a story of her relationships, and what people should be worried about in being with her. The Absolute Headphone Amplifier allows all aspects of the song to be combined to form a whole. The studio effects can be placed, and the layers are audible as the amp has great resolution. The track had great pace and timing, and shows that popular music can be done in creative ways.

In the end, what do you get for your money? EveAnna and her team have put together a comprehensive all in one package. You get a headphone amplifier that is built like a tank and reproduces music for a variety of headphones. It has the versatility to customize and compliment the hardware and software you are using in an aesthetically pleasing affair. This headphone amp can be placed anywhere due to its small footprint, and can even do double duty if you need it as a preamp for a system. I forgot to mention that you even get a remote to control the volume, which has a nostalgic size which makes it large enough so that it cannot be swallowed by a small child or lost easily. You will pay for the pleasure of having this amp in your home, but you definitely have an amp that is scalable to your headphones and includes features that are hardly seen in some headphone amplifiers regardless of price. If you are shopping this should be on your shortlist. Highly recommended. Take care. 

Manley Labs Absolute Headphone Amplifier

Absolute Headphone Amplifier

Retail: $4500

Manley Labs

13880 Magnolia Ave.

Chino, CA 91710 USA