Human Audio Libretto HD CD player




Human Audio is a young company founded in 2004, which tries to say something new in the Hi-Fi field as many other emergent realities do. And the Human Audio Libretto HD CD player has a lot to say. So, first of all, our respect to the men of the Hungarian brand.


These men are Peter Büdszenti, Research & Development, Krisztian Neukum specialist engineer and sales manager, András Gode, designer with studies and teaching experience in Italy, and Attila Juhász, tests supervisor.


Based in Budapest, Human Audio boasts an eclectic production that includes CD players also with DAC “HD” 24/192, USB interface, integrated amp, additional power plants, open baffle dipole loudspeakers and pneumatic suspension. The constant features are the battery supply and the intensive use of bamboo. For further info, click on the company’s webpage beneath the main photo.


We are talking about a situation - plenty of them in Italy - where few enthusiasts gather to create something original, heroic, risky, well below market price, innovative, crazy: it depends from your point of view, from its cost and...from the performances.



We have said bamboo and batteries. The design choice is challenging and extreme. We have recently spoken of a school of thought which tends to avoid metallic or conductive materials, if not indispensable, as well as the mains and its troubles: see our visit to Audio Consulting.

Bamboo is a light plant, one of the fastest-growing plants in the world and suitable for reforestation. Bamboo is of notable economic and cultural significance in East Asia, being used as building material for its low ecological impact and durability, for skyscrapers and scaffolding too.

We can affirm that Human Audio's manufacturing philosophy aims to a harmony between appearance and substance of the object and its performances. They think that an audio component made with natural materials gives a natural music.



The rich documentation provided by the importer, Fabio Carnicchia of Diatone Orgue, proves how much passion and enthusiasm can feed the knowledge of our sector also with scanty means. Unfortunately, sometimes happens that important manufacturers and distributors do not provide many info.


When you open the "eco-sustainable" package, you find a socket with cable to plug in the external battery charger. This is connected to the control cabinet, which has two 12 volts batteries and is linked to the transport via multi-pole "umbilical" cable. The transport has a magnetic clamp and a dust protection cloth to cover the CD when not in use.


Beneath the transport are three disks made of transparent plastic placed on three stainless spheres. The spheres are placed on three concave glass disks (like small bowls) glued on a plate of multilayer glass with an interposed silicone sheet.

Lastly, there is the remote control unit, always in bamboo, like the cabinets of the CDP.


The transport rests on the theoretical points of contact of a circle with a straight line, above and below the three stainless spheres. The combination should turn the residue vibrations into small moves on the horizontal axis, which should not afflict the transport itself. In the video you can see - and badly hear - how this outcome can be obtained also with strong strains. Bumped sensitively, the Libretto keeps on its work of musical performer, coming back inexorably at its place.


The whole battery supply isolates galvanically all the CDP circuits from any possible interference coming from the mains. The batteries are separated for the digital and analogue circuit.

When the CD player is connected to the power supply, the charger can be connected to the mains supply permanently. This because the charging will be automatically isolated when the Libretto is turned on.

The charger is completely automatic, you do not have to do anything. Human Audio suggests to recharge the batteries only when the umbilical cable connects the two units and to avoid removing it when the charger is connected to the mains.


On both units, two LEDs indicate the charge status. The one on the charger illuminates the front plastic disk placed on the underside of the cabinet. The green light leads off to the full operation that is up to 36/48 hours between charges. The red light indicates the "reserve". Since the recharge is not possible during the operation, when the charge is over the CDP goes in stand-by and will not work until the minimum amount of energy has been reached.

The Libretto is controlled from the front panel of the battery housing. Unfortunately, it is very difficult to read the OLED display from a certain distance.

Inside the transport, we find a high precision clock, a converter at a 24-bit resolution, a high quality output stage with coupled JFETs, and - secret of the secrets of the best interface - some small selected output transformers, made by the American Jensen.

The Philips Pro2 Industrial transport is solidly fixed on the chassis, without springs, rubber tips or any other kind of suspension. Some damping material, like Blu Tack is used on the components that might suffer inducted or self-generated vibrations.

RCA and XLR sockets are professional at 600 ohm and cannot be used at the same time. Other output typologies are available on demand.


Every CD has to be read first by its TOC (Table Of Contents) by pressing the small button next to the CD transport. The CD is then ready to be played and all the controls now are the usual ones, on the panel of the battery housing or on the remote control.


There is also a S/PDIF input with BNC connector if you want to use this version of the Libretto as DAC only.


Listening test

For convenience, I write my notes from the musical examples of only one great CD that we all must own: Arabesque by Crystal Cable. The direct sound recording, the discographic and editorial work by Gaby (Crystal Cable) and Edwin van der Kley (Siltech) is au pair with their respective manufactures of cables.


Vivaldi, Violin Concerto In G, Op. 4/3, RV 301, La Stravaganza #3 - 1. Allegro, Arte Dei Suonatori directed by Rachel Podger - Size of the concert hall and instrumental positioning clearly detectable.

Taquito Militar, Alfredo Marcucci, Juan Masondo and Michel van der Meire - Sensation of the live event related to an ethnic ensemble. It seems like being "in the street" with them.

Mussorgsky, Pictures at an Exhibition - The Great Gate At Kiev, Minnesota Orchestra, director Eiji Oue - The emotionality of the musical changes and of the different passages is given with lots of means and confidence: a misty-eyed feeling.

Saint-Saëns, Danse Macabre, Minnesota Orchestra, director Eiji Oue - A very deep sound scene and continuous changes of perspective due to the score that are very well given, in a crescendo of emotions.

Variation of J.S. Bach's Goldberg Var. XXI, Kalman Olah Trio - A modern rewrite and jazz for a track of physical involvement, very close to the performers.

Bach, Suite For Violoncello Solo - BWV 1007 - Prelude, soloist Pieter Wispelwey.

What can be better appreciate is the neutral ambience, nor dark neither cold.

Monti, Czardas, director Vag Papian, Maxim Vengerov violin - Virtuosity at the violin which is rough and woody without "electric" notes: an outcome that not so many CDPs can offer.



It has been said many times, maybe too much, but there is no other way to say it: at last, a CDP that does not play digital. Compared with a good analog set-up gives justice to the qualities of the digital, giving that naturalness of emission so rare in our more technological players.



Not suitable for the faint of heart. It is quite impressing seeing the transport floating or moving at the minimum hit. What has to be paid for this object of continuous research is its limited practicality. It has to be treated like an "intelligent" turntable more than a "stupid" CD player.


Also the big and heavy connection cables cannot be recommended as they tend to move the transport barycenter which has not a big mass.

You cannot go straight to a particular track. I mean, if you want to play track four you must press the 'next track' button four times instead of a button marked '4'. Together with the small display (alas not reported on the remote) these two features unbearably increase the limited mnemonic possibilities of all of us, lazy audiophiles...



What does it take to create a minimalist CD player, with an analogical sound, almost "environmentalist" with battery power supply? Why it has not been made before? Why no one else has tried to do it?


Quick metaphors and final recap

Fluency of the sound message, precise but palpable detail, completeness of the ranges, no listening fatigue, etc., etc. Compared with CD players traditionally supplied, the Libretto has won definitely, excepted for the apparent dynamics and rise time of the transients and for the mass and the immanency of the low frequencies. These statements need for explanation, though. We are entering the mystic/misty of the "idiophile" reviewer.


Rise time, dynamics, transients are different for sure but, to better understand each other, the feeling is that the Libretto, like few other great Hi-Fi machines, does not "chase" the sound but propose it with the right timing. Sometimes is appears even dilated, but this "time dilatation" is a symptom of a great introspection of the sound message, of wide percept dynamic excursion and a distinctive mark. Many CDP with traditional power supply seemed more ready in some passages, but with an absolute reduced dynamic excursion. In other words, with the Libretto you can hear a bigger difference and distance between pianissimo and fortissimo.


Dimension and physicality of the bass: here is the energy that decays, as there were a hint of energy reduction in the sustaining of these frequencies. I am talking about nuances, of course. This happens also in the more agitated rhythms, where the intelligibility is constant, but the impact drops a bit.


In synthesis, the Libretto is a CD player where the last grip maybe is missing, where the articulation is privileged with respect to the impression, but where everything else has been done from a good to an excellent way.

Maybe I am intellectually fascinated because I intellectually adhere to Human Audio design intentions. The fact is that for me the Libretto is one of my reference sounds in a worldwide Top Ten.



Tone colour | extension in frequency, ability to faithfully reproduce the instrument and its harmonics

The high notes are natural, never tiring. The midrange always correct: I do not report examples of voices, but is in the voices that the Libretto's naturalness is more convincing. Great articulation of the basses, absolutely without any swelling. They be short of energy only apparently.

Dynamics | micro (detail) and macro (absolute) transients extension and rise time

A record. A disarming easiness in analyzing and giving back the detail before "playing loud" without any worry.

Image | ambiance, transparency, scene, sound planes, virtual stage, sense of presence, resolution

Analytical without any coldness. The differences of ambience among the sound supports are instantaneous.

Tone | general equipment setting, if present, or characteristic: e.g. warm, cold, changing, amber, glossy, mat ...

Great tonal balance. Very similar to the stylistic code of the sound with coupled transformers.

Emotion | the capacity of emotional involvement, depending a lot on couplings, an absolutely anarchic and personal parameter

You need to clean your ears to understand it because it can surprise you. In absolute, it is one of the more involving CD players.

Manufacture and Packaging | Strong but small, entirely recyclable, with wood-grained inset handles and Velcro re-closing. Original is its "ecological" preciousness.

Price/quality ratio | You pay for the design, for the determination in reaching a conceptual target. You need to "believe" or be convinced by the results. I would like to make a comparison with the Gold Note Favard CD player, which, notwithstanding a higher price, states twelve (12) separated power supply stages.


Official technical specifications

Formats: CD-DA (Red Book, CD-R Audio, CD-RW Audio)

Transport: CD-Pro2 Industrial

Converter: Wolfson WM8804

Suspension: LIBRA® - Vibration Damping Pillow

Conversion D/A: 24-bit Hybrid Mode

Frequency response: 20Hz-20kHz +/-0,5dB

Total harmonic distortion: <0,025%

S/N ratio: >110dB

Dynamic range: >105dB

Power supply:

internal with sealed batteries and without maintenance - SLA

external with CE 100-230V AC automatic recharger

Operation time: 36-48 hours full charge

Charging time: 12 hours max

Analog outputs: XLR (AES/EBU) 110ohm, RCA (coax) 1kOhm

Digital outputs (optional and only in the non HD version): XLR (AES/EBU) 110ohm, RCA (coax) 75ohm

Digital input: S/PDIF (BNC)

Dimensions: 180x100x270mm (WxHxD) x2

Weight: 10,5kg

Official Italian dealer: to Diatone Orgue website

Official current price in Italy: 10,700.00 EUR

Associated equipment: to my system

An "open" Libretto without its cabinet
previous slide next slide
The transport base, with the glass
The transport base, with the glass "small bowls" and the supporting stainless spheres
An exemplar image of the contact points between the transport and the base
An exemplar image of the contact points between the transport and the base
by Giuseppe
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