Manley Absolute Headphone Amplifier Review

The name Manley has been legendary in audiophile and professional audio circles for many years now, and I recall my dad lusting after VTL and Manley high-powered tube gear when I was younger, not just because of its sound, but also because it was expensive. But, not so expensive that it was totally out of reach for the average Joe who saved their pennies. Likewise, the piece of gear on hand today is quite expensive, but not in the Millionaire-club stratosphere of Summit-Fi. I’d wager it is just about at the limits of what most headphone listeners can afford in a top-tier headphone amp, but attainable if you save quite carefully.

I mention this because EveAnna Manley, who is the personable head of Manley Laboratories, is one of the few two-channel company heads I know that decided to do a headphone amplifier right. What I mean by that is that instead of simply knocking out a quick design, pricing it stratospherically, and treating it as a second-citizen of their product line, Manley dedicated herself to the task of making an exceptional amplifier and she even shows up to CanJams and audio shows and runs the headphone booth personally. The two of us have had numerous conversations about what the great sounding current headphones, DACs and other trends are, and it’s confidence-building to see a manufacturer who is so excited about all aspects of sound – not simply the single golden-child project they’ve been working on refining their whole careers. 

The Manley Absolute Headphone Amplifier.

This brings me to my next point, which is that Manley Labs is not a company built on single technologies or topologies, but because of their pedigree in the professional world and expansive amplifier catalog, the best topology for the job is auditioned and tweaked extensively. This is reflected nowhere more in their consumer line than the $4,500 USD Absolute, which includes a technology which first showed up in their two-channel amplifiers, whereby one could switch between Ultralinear Push-Pull and Single-Ended Triode topologies on the fly. 

Manley’s Absolute headphone amplifier includes this same switching functionality between Push-Pull and Single-Ended Triode modes, but goes three steps further in functionality, also incorporating a variable feedback/gain control, an EQ, three output-impedance modes and a balance and mono control. That’s a lot of functionality with complex interactions, so let’s break it down. 

Build, design, features

Stunning attention to detail in the build execution and design.

First, the Output Impedance button, labelled H, M, L. I mistook this for a gain switch at first and was a tad confused initially. This actually changes the output impedance to Low (12-50 Ohm), Mid (50-200 Ohms), High (200-600 Ohms), and is designed for matching variable headphone impedances. I generally found I liked to live in the Low or Medium zones with most headphones, but some folks who really love a sense of that softer sound of high output impedance tube amps may like the highest setting on lower impedance headphones. Interestingly enough I found the medium and high settings not much different for low-impedance planars, while the highest setting actually sound clearer for headphones such as ZMF Verite 300-Ohm dynamic or other high-impedance dynamics like Sennheiser HD series headphones. For a softer listening experience with what sounded like relatively less gain, I could actually use the Verite or HD headphones with the medium setting, and found this very pleasing for longer or more relaxing listening sessions where I might be settling in to a more ‘ambient’ session. 

Next, I found the Feedback control to have a very subtle, but important interaction with the Impedance control: It actually seems to act as two controls in one. Feedback can be adjusted between 0 and 10dB of negative feedback. It also acts as a kind of gain control – as you increase feedback, effective-gain decreases, with total final gain being a factor of the load being driven, mediated by how much feedback is used. Manley lists a few loads and example of gains at minimum and maximum feedback. Needless to say, this control is quite complex, and you can get some very interesting results between it and the Output Impedance control, with everything from gentle harmonic effects to bold tone-shaping possibilities. 

Doubles as a headphone stand.

Manley still weren’t satisfied with this however, as they also tossed in a set of Baxandall EQ filters and both Mono and Balance functionality. Anyone with hearing loss or old mono records will appreciate the balance controls, though they were more ‘nice to have’ than necessary for me. The EQ was the real star of this show however, and Manley’s pro-audio heritage shines here. Most hi-fi companies, when they implement EQ controls, design simple bell or shelf filters, boosting frequencies in a given area pretty equally. The Absolute uses Baxandall filters which have subtle tapering and shaping around the outermost affected frequencies, and combining both controls can give interesting effects, such as boosting or cutting the midrange – if you’re a tweaker this will give you hours of endless fun. 

Taller, not wider.

More importantly, however, it means you can balance the effects of feedback and gain with EQ, so, if for example, you like the tonal richness of less feedback, but would prefer the relatively less-punchy sound of lower gain, you can adjust the output impedance down a notch, then compensate for lost bass and treble with the EQ controls. Or you could increase feedback, flip the amp into Single-Ended Triode mode and decrease EQ and treble to bring the midrange forward and minimize noise and maximize midrange frequencies on a headphone with a V-shaped frequency response. The interactions are incredibly fun, but complex, and there are no rules other than using your ears. I found the flexibility of the unit astounding in this regard. Between feedback, impedance, EQ and the two amplification topologies, I could alter not only the frequency response, transient quality and relative signal-to-noise ratio, but also the harmonic structure and character of the amplifier. Everything from nearly solid-state – in linearity and punch – to extremely rich and warm was available.

Manley Labs
13880 Magnolia Ave. Chino, CA 91710 USA
+1 (909) 627-4256

Simply Nobody's picture

Is it the 'absolute best headphone amplifier'? ....... Sounds like it :-) .......