Back in the late nineteen eighties I ran a small boutique by appointment only high end Hi-Fi shop, and at that time our preamplifier of choice was the Manley (their first and only product at the time if my memory serves correctly), which we considered to be the finest audio product in the world. Not long after that, Manley moved into pro audio which they quickly took by storm and has remained their primary focus ever since. When I met Zia Faruqi at T.H.E. Show Newport 2016 demonstrating the original samples of the Manley Absolute Headphone Amplifier I knew this was a product I had to review. Not only was it aesthetically distinctive and beautiful, it offered unique features not seen before in Personal Audio, and exceptional performance that was apparent even at a crowded HiFi show.
If I have this correctly, Zia Faruqi was David Manley's first employee at the first Vacuum Tube Logic company in England in the 1980's. The Absolute Headphone Amplifier was Zia's brain child and he is responsible for the Design Concept, Industrial Design and acted as Project Manager throughout the entire development process going so far as to personally accompany the product to a plethora of Personal Audio Expos.
The MANLEY Absolute Headphone Amplifier
In addition to the EQ bypass switch there is a button for mono, source, output (1/4" 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 the Absolute Headphone Amplifier as a line-level preamplifier in an existing hi-fi system) and a button that cycles the transformers through three ranges of output loads (Low 12-50 Ohm, Mid 50-200 Ohm, High 200-600 Ohms).
There is also a selectable Bypass Thru Mode that sends RCA Input 1 directly to the RCA Outputs, when in STANDBY mode, as well as a user adjustable Headphone Overload Protection System which allows you to preset a maximum output level.
Which brings me to the two most interesting and unique features; the first being the ability to switch on-the-fly between all-triode Push-Pull to Single-Ended topology. Essentially, in Push-Pull mode the Harmonic Distortion is significantly lower, power output is greater and noise floor should be lower, whereas Single-Ended completely alters the harmonic structure from odd-order to even-order which is more musical.
The other is my favorite feature the Variable Feedback control which allows you to control the amount of overall negative feedback applied to the amplifier from 0dB, or no Global Negative Feedback, to 10dB of Negative Feedback.
"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 versus shimmering, or punchy versus mellow."
On to technical features; 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. It also incorporates their 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 review sample I received was fitted with Ruby 12AX7WBC input tubes and RCA 6AQ5A vacuum tubes in the output. The solid billet chassis for the Manley Absolute Headphone Amplifier is available in three color options: Black, Copper, and Silver, and feature hand-rubbed walnut-burl veneer accents for the headphone head-band and ear pad rest areas.
I will start with, you get out of the Manley Absolute Headphone Amplifier exactly what you put into it, which is high praise for an amplifier, and unusual for headphone amplifiers, especially tube headphone amplifiers because many Personal Audio designers seem to be under the delusion that the amplifier should somehow "improve" the sound of the signal fed into it, this usually means rolling off the highs or adding bass or midrange, or adding delay to create more "air", or messing with the phase to create a more three dimensional image and soundstage, or dynamic range expansion, or a myriad of other tricks to fool people into believing an amplifier sounds better, not to mention basics like TIMD which makes the amplifier sound crisper, and gives the impression of added detail (well there is added detail, the Transient InterModulation Distortion itself, but that's not music), when in fact any change in the signal is simply degradation and distortion.
After a bit of experimentation, I found that running single ended with the Negative Feedback set to its fully on position (the default position) most fit my tastes and produced the greatest musicality. Listening to Artur Pizarro & Vita Panomariovaite piano duo performance of Rimsky-Korsakov's "Scheherazade Op 35Andantino quasi allegretto" (Nikolay Rimsky-Korsakov Piano Duos 24-bit/48kHz) through the ETHER C Flows was a magical experience with the piano reproduced full and natural in a large recital hall with excellent dynamics, timbre, speed and soundstage.
Dusty Springfield's voice was palpable and intimate through the ETHER2s for "The Look of Love" (Casino Royale 24-bit/192kHz) bracketed on a Jazz Club stage by the upright bass, drums, piano and guitar. The saxophone, brass and strings were warm and inviting without any of the usual harshness associated with those instruments.
The LCD3s let me explore the Absolute Headphone Amplifier's ability to handle higher impedance loads, and the on the fly impedance switch made it quick and easy work to change headphones. "Sister Seagull" from BeBop Deluxe's Live In The Air Age (16-bit/44.1kHz) was reproduced lifelike and lively with a 10th row at the Forum soundstage.
Anytime I have a Class A Triode amplifier to audition, I am almost compelled to run vinyl, and the Manley did not disappoint. Nicky Hopkins' No More Changes was a true pleasure to play though the Absolute Headphone Amplifier regardless which headphones I used. The higher resolution of the ETHER2 was put on display for "The Lady Sleeps" bringing out the multiple piano tracks and the sweetness of the guitar leads.
The Come Away
As expected from a true audiophile piece, it demands a top end source and is able to reproduce every nuance fed into it, and likewise it will pull out the pinnacle of what your headphone can achieve, but it will not change the basic character of those headphones.
The switchable single-ended or push-pull topology and the variable negative feedback control give real insight into those technologies and why they exist (it should be pointed out that negative feedback in a tube amp, and negative feedback in a solid state amp are completely different animals, negative feedback in a solid state amp can produce high levels of TIMD which is not a factor in tube amps).
I found the Manley Absolute Headphone Amplifier to be beautiful, versatile (you would be hard pressed to find a headphone that it does not work well with) and fantastic sounding. To put it simply, the Manley Absolute Headphone Amplifier is evidence of why those who dabble in the extreme high end of the audiophile world lean towards tube amps.
Maximum Input Level:
Outputs (transformer coupled):
XLR-pin outs - (Left Channel Pin 1= Signal (+), Pin 2= Signal (-), Right Channel Pin 3= Signal (+), Pin 4= Signal (-))
Maximum Output Power = 1W into 12 Ohms BW 22Hz-22kHz
Variable Feedback Control (FB):
Signal to Noise Ratio:
Balance Control Channel attenuation:
Supplied with Remora RF remote control
Voice: (909) 627-4256