Manley Labs is proud to announce the release of a stunning design: the Absolute Headphone Amplifier. Brimming with functionality, this new art piece from Manley Labs is as enthralling musically as it is handsome visually.

With over three years of development in its creation, Manley has drawn from its 30 years of experience in conceptualizing and developing each precise element of this multi-talented unit. This masterpiece embodies high-performance flexibility for every person to be able to custom compose sonic performance reliably, repeatedly, or even spontaneously. Artistic expression with sound!

Oh, and by the way, it is also a Line-Level Preamplifier!

DETAILS

There are fifteen independent controls available, each of which was exhaustively developed for convenient adjustability and aural variety. Two selectable stereo RCA jack pairs receive the input signals. Even these RCA jacks are of our own design. Teflon® insulated and gold plated, we have been producing these excellent RCA jacks since the mid-1990s. The volume is controlled on the facia by the sexy front thumb wheel and also by the included Radio Frequency remote control, both of which operate a precision stepped relay ladder matrix attenuator in half dB steps. The RF remote can be operated anywhere in the home, even through walls or cabinetry, especially useful when using the unit as a stand-alone preamplifier. Next to the front volume control wheel you’ll find the Mute switch to instantly kill the signal. Spinning the volume wheel all the way to minimum also mutes the signal.

And you know how maddening it is to try to listen to a mono LP record on headphones - which is why we have provided a MONO switch!

In case your source needs some correction or if your own ears do not hear equally, we have included a Balance Control which can swing the signal up to 72dB either way. In its center detent position, this special balance control is completely out of the circuit. Also to be able to execute some sonic authority over what is handed to you in a given recording or to just make your headphones sound nicer (to you!) we have provided historically proven pleasing and gentle Tone Controls - and these Baxandall Bass and Treble equalizers can be completely bypassed at the push of a button. Try them! We think you really will enjoy having the choice to enliven and enrich your sonic experience.

Along those lines, the Variable Feedback control allows you to control the amount of overall negative feedback applied to the amplifier from 0dB, or no Global Negative Feedback, to 10dB of NFB. Negative Feedback in electronics is when a small portion of the output signal is re-introduced back to the input signal to provide a more stable and beneficial corrective result. This control is very useful when determining how “tight” you want your amplifier to sound. For example, a simple female vocal with minimal percussion can sound more intimate with very little feedback, but a complicated symphony orchestra passage may sound better positioned with more feedback. Applying different amounts of negative feedback can also affect the slew rate and apparent “speed” of the sonic character. Other aspects for which to listen include placement, forward or relaxed, darker vs shimmering, or punchy vs mellow. Feel free to play with this knob and listen for the not-so-subtle diversity that altering the amount of feedback provides. It’s one of our favorite circuit tricks and we’ve been pulling this one for decades!

Ah! And our other coolest tonal trick: Switching Topology!
We’re pretty sure we originated this concept in the audiophile world back with the Manley SE/PP 300B power amplifiers and it’s only because we have our own in-house magnetics department that we are able to devise such complaisant output transformers that can accommodate such radical demands. The Absolute Headphone amplifier features custom hand-wound air-gapped dual-mode MANLEY IRON® output transformers, designed and manufactured at the Manley Labs factory in California. Interestingly, the output tube stage can be switched on-the-fly between all-triode Push-Pull to Single-Ended topology. This completely alters the harmonic structure from odd-order to even-order and basically halves the output power again providing yet another spicy ingredient to flavor the sound.

Additionally, with a push of a button, these transformers cycle through three ranges of output loads accommodating headphones from 12 to 600 Ohms or greater. Choose between three sets of outputs: the expected ¼” TRS Headphone Jack, a 4-pin XLR Balanced Stereo Output for your high-end balanced headphones, and a set of stereo RCA outputs to use this component as your line-level preamplifier in your existing hifi system. The Bypass Thru Mode sends RCA Input 1 directly to the RCA Outputs, when in STANDBY mode. Useful, as your main audio system sources can drive either playback system without having to change upstream cabling.

DRIVEN BY MANLEY POWER®

The Absolute Headphone amplifier incorporates our own innovative purpose-designed-for-audio High Voltage switched-mode power supply. All super-low impedance DC rails are fully regulated and worlds quieter than any linear supply we have ever encountered. The resulting sound is fast and dynamic with a deep punchy bass, deadly-quiet inky blacks, and superior headroom.

The 6AQ5 or EL90 is the vacuum tube used in the output stage of the Absolute Headphone amplifier. It is well suited for our purposes in a headphone amplifier. The tube is configured as a triode due to the low power requirements needed for headphone use. This tube is widely available from well-known manufacturers such as RCA and GE. The tubes can be ordered as a matched quad and for ease of use the tubes do not require biasing. Simply plug them in and forget ‘em!

We offer the solid billet chassis for the Manley Absolute Headphone Amplifier in three color options: Black, Copper, and Silver.

All three options feature carbon fiber accents for the headphone head-band and ear pad rest areas.

With its universal power supply allowing it to operate anywhere in the world, robust build quality and breathtaking audio playback, the Absolute Headphone amplifier is at home absolutely anywhere, from a cozy listening room, to your bedside, on your office desk, or as a reliable workhorse in a professional recording studio. Conductive plastic pots and film caps are just some of the fine components utilized, proven over decades of loyal use. Manufactured completely to stringent standards in California, USA, crafted by hand, by American workers, the Manley Absolute Headphone Amplifier certainly makes for a formidable player in today’s headphone listening arena.

This very unusual and visually striking audio sculpture was brought to life by Manley’s team of engineers including Mitch Margolis - of Manley STEELHEAD fame - and our lead engineer Humberto Rodriguez, finalizing the amplifier and bringing it to life and into production - in America, of course!

EveAnna Manley, President and co-founder of Manley Labs observes: “Headphone listening is not new to us; we have been producing personal headphone playback systems aka “Cue Mixers” for recording studios around the globe for well over twenty years. In the HiFi world, our legendary Manley Neo-Classic 300B Preamplifier has become a total cult classic with headphone listeners since the mid-1990’s. Reaching forward, we wanted to produce an extraordinary sounding headphone amplifier chock-full of features and sonic variety for the audiophile, at a price that wouldn’t break the bank either. I know you’re going to Absolutely LOVE this exciting creation of ours.”

Q: Does the Manley Absolute Headphone Amplifier have enough power to drive my Abyss 1266’s?

A: From our good customer John A. in AZ, he reports, “The Absolute drives the Abyss TC1266 (latest version) planar headphones without issue and that is good to know as they aren't easy to drive but [they are] one, of if not the best, planar on the planet we inhabit.”

Q: Well what about the HiFiMANs? Aren’t those SUSVARAs impossible to drive?

A: No problem for us! We have been using HiFiMAN HE1000’s as our main testing headphones since day one R&D with the Manley Absolute Headphone Amplifier. After Mark at HiFiMAN heard our Headphone Amplifier at a trade show driving the SUSVARAs, he bought one of our units for his demo rig and to use as his in-house reference amplifier as well!

Q: I haven’t decided what headphones to buy. What do you use?

What we have in our arsenal are:

• HIFIMAN HE1000 original v1 and HE1000v2 and HE6se, and the Manley Absolute Headphone Amp can drive any of their stuff, even the Susvaras.

• Audeze LCD-4 rich and luscious sounding!

• FOCAL UTOPIA (love the Stellias too!)

• Dan Clark Audio (formerly Mr. Speakers)

• and various IEMs from CARDAS, SHURE, ETYMOTICS

I haven't found a headphone that our unit won't drive! Basically the world is your oyster!

Q: Why can't I have balanced inputs?

The input stage of this amplifier, and the way the feedback is configured for the amplifier is configured for this single-ended input stage design. The input circuitry uses single-ended topology. In order to be able to provide balanced inputs we would have to convert the signal from balanced using something like some IC's or transformers. Both these options would add more "stuff" to the signal and be certainly audible detracting from the pure sound this amplifier provides. If you are driving this headphone amplifier from a balanced preamplifier, check to see if you also have unbalanced outputs, change your cables and go with that. You might be pleasantly surprised that they too added extra audible "stuff" in order to provide balanced outputs and the RCAs on your preamp that don't have that extra "stuff" in the signal path actually sound better. (Depends on a given unit's specific design.) Or use some XLR to RCA adaptors. Most balanced gear has no problem driving single ended but check with the manufacturer if they are going to want the negative pin 3 of the XLR grounded or floating. Transformer-coupled XLR jacks always can drive single-ended by running Pin 2 to the HOT middle RCA pin and grounding pin 3 to the RCA outer shell. Some IC coupled XLR outputs will want pin 3 floating, others will require it to be grounded when driving a single-ended input. Check with the manufacturer of your gear to see how to hook it up to a single-ended input.

Q: My remote is not working. Send me a new one.

All remotes are paired up when they ship out. However, if at some point, if both UP and DOWN buttons get pressed at the same time, it will un-pair the remote and it will need to be re-paired. Follow the pairing procedure in your REMORA REMOTE manual to mate it up again.

Q: For the input tubes, may I try the 5751 instead of the 12AX7 tubes?

A: One of our customers told us, "I am finding the Absolute has even better focus and timbre with the 5751. ...there are some good JJ5751s currently made. True, I am using some Sylvania GP but the 5751 in general has a very good focus to the sound, with good layering and a solid bass impact."

One of our engineers warns, however, "I think in general I like the sound of the 5751 over a 12AX7. However in the Absolute headphone amp the lower gain of the 5751 drops the overall sensitivity of the amp and it does not reach acceptable volume levels with a standard 1VRMS device such as an iPhone, especially with max FB and PP."

So the answer is, yes you can try 5751 tubes in place of the 12AX7 input tubes but you will not have as much gain, so be aware of that! If you have an abundance of input level drive, no worries.

Q: Single ended is noisy but still amazing. Best sound to hit my ears. Pricey but well worth it. Keep making awesome stuff.

Yeah sorry, if you are using low impedance headphones and using the high Z output and 0 Feedback, this would be the worst case scenario, and show off worst case noise in SE mode. We would call that a "disallowed state". Apply some feedback or lower the output impedance to fall into acceptable noise figures.

Q: I am turning the EQ controls but I can’t hear much difference. Why?

Number one, make sure you have the EQ Bypass switch set to "IN" with the LED illuminated and not Bypass! The Bass and Treble EQ is way out on the edges of the frequency spectrums so you won't hear a big change! That's normal. Look again at the frequency response curves for the EQ in the owner's manual and you'll see why the effect is subtle. This EQ circuit is not trying to make sound effects. Just trying to solve problems....

Q: The volume wheel has come loose. How do I tighten it back up?

You will probably want to contact Tech Support as we have some disassembly videos we can send you and it’s a bit tricky… but importantly, the hex allen key that you’ll need to re-secure the set-screws that hold the wheel onto the volume encoder is a very small weird size of 0.035”. Let us know how we can help.

Q: Didn’t you guys used to offer wood burl accent inserts?

Yes, we offered walnut burl inserts for the first few years of production. They were laborious to hand-rub, wax, finish, and install and the heat of the chassis accentuated wood’s propensity of expand and contract. The issues of imperfections and inconsistencies have been solved by moving to carbon fiber inlays instead. Plus carbon fiber makes it run faster! 😎