The idea of designing a reference amplification grew in Avantgarde Acoustic for quite some time. It grew in Matthias Ruff's head to be exact, the company’s chief engineer. He is an extraordinary man. Truly committed to what he does, working according to his own agenda and at his own pace. He comes to work in his lab in the evening, when others go home, and sometimes he spends there all night. As he says that allows him to truly focus on the job at hand. If you ever had a chance to talk to him you probably noticed that he seemed to think about something else, being somewhere else. And that might be true, as he always thinks about improvements to already existing products and about new designs. It seems that sometimes he is so much focused on that that he forgets about the world around him. And that's not really a good thing in a real world; it might be dangerous – a year ago, when cycling home (he always travels to and from work on bike) he rode into something so hard, that he couldn't walk for quite a long time. Fortunately he recovered and those who visited this year's High End 2012 in Munich (read HERE) had a chance to meet him at the Avantgarde Acoustics’s stand.
I've known him for many years and I talked with him many times, in Munich but also in Krakow, where he arrived a few years ago promoting the brand (I wrote a report about that visit for “Audio”). And each time I meet him he always has something new, interesting to say.
He is a perfectionist, and as all of them he always thinks that whatever he did might be done even better, or improved. As Mr. Holger Fromme, the owner of Avantgarde, once said, each product at some point had to be taken away from Matthias almost by force to put it finally on the market. And, of course, when they forced him to present a particular model for production he was always unhappy claiming it wasn't as good as it could have been if he had enough time. But it is business and each manufacturer must release new products from time to time, so Mr. Fromme does what he needs to do to introduce great products to the market. The new electronics series – XA Series is a great example. The company prepared very nice brochures, a video manual, ingenious pictures – everything was ready when it came to market launch, which is quite a unique approach even in high-end world (which always makes me wonder – how come that all companies don't do it, they sell luxury goods after all, comparable to cars, motorcycles, yachts and so on). Pictures delivered by AA are so good, so precise, showing all design details, that for the first time ever I could use for my review only the pictures delivered by the manufacturer (except for picture no. 3 that shows Mr. Fromm during our meeting in Krakow). What's more – these are probably the best pictures ever presented in “High Fidelity”!

We clearly learned how important this new line of electronics was for Holger Fromme when he came to a Krakow Sonic Society meeting in March 2012, held at our friend's Tomasz place (read HERE).
It created a unique opportunity to talk to him about all aspects – technical, business related, about problems that appear when manufacturing of new model starts, and so on. If only you could see how Mr. Fromme smiled when he discussed the XA Series – it was (is) his “beloved child”, I have no doubts about that. If you take a look at the pictures and read the meeting's report you will probably understand why. From the very beginning the idea was to create something very special, unique, and different from anything the competitors offered. If you look at this device you will see it at once – its external design is like nothing you've ever seen. A large knob with LED indicator working in a unique way, a huge, sturdy aluminum enclosure, solid handles on the front panel that are actually helpful when moving the preamplifier – all those elements make the device stand out from the others. But wait, there is more – that design can be “customized” to fit customer's interior design or the color of Avantgarde Acoustics’s speakers should the device be used with them. It is done by replacing the front panel – which can have metal finish (black or silver anodized), high gloss lacquer finish (all of Avantgarde Acoustic horn colors are available), or wood-like finish (several natural veneers to choose from). You can also choose a color of a stripe beneath input selector switches, the color of volume control knob, or the handles. You also choose black or silver remote control. There are numerous possible combinations (I dare the readers to try counting them all), and when the customer makes all of his or her choices, he gets a bonus – a tablet placed on the back panel with the customer’s full name engraved in it. Yes, that is quite a “personal” piece of audio equipment…

The XA Series PRE is also a really “user-friendly” device – the large volume control knob or the amazing remote control of the same size and finish allow easy and precise volume control. There is a volume control LED indicator. When you change the volume several LED lit up for a moment and then only the one showing final volume stays on. There is a back-lit window behind the volume control knob. The back-lit color changes according to the actual status of the device: it’s orange when the device is on and the batteries are being charged, white when the device is powered exclusively from the batteries, and blue when “Mute” mode is on.
For the PRE operates with a battery power supply. That was one of the very basic Matthias’s ideas. Signal path is extremely short – there is a single gain stage only. And it sports hand-picked, thoroughly measured transistors, placed inside round metal enclosures. The volume control is based on resistor ladder. Also other elements used in this design were picked after thorough research – these are for example capacitors from Sanyo, or Rubycon Black Gate (company bought a large quantity of those on after-market to keep a stock for future use).

SOUND

Our previous texts about Avantgarde Acoustic:

• Paganini for two, Gil Shaham, Göran Söllscher, Deutsche Grammophon/JVC, 480 246-5, XRCD24 (1993/2009).
• Stereo Sound Reference Record. Jazz&Vocal, Stereo Sound, SSRR4, SACD/CD (2010).
• André Previn, After Hours, Telarc/Lasting Impression Music, LIM UHD 051, CD (1989/2011).
• Assemblage 23, Bruise, Accession Records, A 128, Limited Edition, 2 x CD (2012).
• Beverly Kenney, Beverly Kenney sings for Johnny Smith, Roost Records/EMI Music Japan, TOCJ-9731, CD (1956/2012).
• Beverly Kenney, Come Swing With Me, Roost Records/EMI Music Japan, TOCJ-9732, CD (1956/2012).
• Depeche Mode, Personal Jesus 2011, Sire/Reprise 21328-2, MS CD (2011).
• Dominic Miller & Neil Stancey, New Dawn, Naim, naimcd066, CD (2002).
• e.s.t. Esbjörn Svenson Trio, 301, ACT Music + Vision, ACT 9029-2, CD (2012).
• Handel, La Maga Abbandonata, Simone Kermes, Maite Baumont, Il Complesso Barocco, dyr. Alan Curtis, Deutsche Harmonia Mundi/Sony Music Entertainment, CD 88697846212, CD (2003/2011).
• Kraftwerk, Minimum-Maximum, Kling-Klang Produkt/EMI, 3349962, 2 x SACD/CD (2005).
• McCoy Tyner, Nights of Ballads & Blues, Impulse!, IMP 12212, 20-bit Super Mapping, CD (1963/1997).
• Me Myself And I, Do Not Cover, Creative Music, 005, CD (2012).
• Pat Metheny Group, Offramp, ECM, ECM1216 422 817 138-2, CD (1982/1994).
• Portishead, Dummy, Go! Disc Limited/Universal Music Company [Japan], UICY-20164, SHM-CD (1994/2011).
• Sara K., Don’t I Know You From Somewhere?, Stockfisch, SFR 357.6055.2, CD (2008)
• The Beatles, 09.09.09 Sampler, Apple/EMI Music, 84414 2 5, 2 x CD
• The Beatles, Rubber Soul, Parlophone/Apple/Toshiba-EMI, TOCP-51116, CD (1965/1998).

Japanese editions are available from

What's fascinating about audio is how our perception of the sound changes even when the only actual change in the system is one device. What's more, I am pretty sure that if we took measurements of say the Soulution 720, the TAD C-600, and the Avantgarde Acoustic PRE the results would be similar. All these devices are extremely well built, all measure damn well, all were designed by engineers and then finely adjusted after numerous listening sessions. Key features of each one of them are: oversized power supply, extremely short signal path, and volume control attenuator based on a resistor ladder. All of them also sport extremely rigid, well-built enclosure. And all of them have solid state gain stages.
Looking at all these similarities, reading tech specs one might think that all of them would sound the same. And while there are actually some similarities between them that I think might be related to their solid state circuit designs, there are in fact more differences plus each of them has some common attributes with every other preamplifier that I reviewed for this issue, regardless if it is tube or transistor based, two or one box design.

The PRE delivers very smooth sound. I found that description in my notes over and over again and it concerns all those preamplifiers. This is an important sonic aspect of each of those devices. The Avantgarde Acoustic preamplifier offers extremely smooth sound, almost as smooth as the Soulution 720. What I find interesting is that the Audio Research Ref5 SE, the ModWright LS 36.5, and my Ayon, all being tube devices, in comparison, offered a bit more grainy sound, or a bit less clear. It might prove that at extreme sound quality level some reservations of engineers concerning distortions introduced by tubes (and there are some, that's certain) are true and that in this aspect solid state might be a better choice. That's only one aspect of the sound and what really matters is the big picture. But listening to the PRE and comparing it to tube preamplifiers I started to understand those who preferred not to have tube distortions in sound.
Yes, the PRE offers amazingly smooth sound. Silky. Regardless of the recording I listened to. That preamplifier blends into the system very smoothly. Midrange and treble are of absolute clarity, but also rich, well saturated. Sound isn't dry at all – in this aspect only the TAD C-600 (among solid-states) and tube preamps offer more. But the difference is not too big.

Tonal balance is slightly shifted up compared to the TAD and the Ayon, and it seems more or less the same as that offered by the Soulution. There is also very well extended, well defined bass, very nice midrange and amazing treble with great sense of openness.
Bass deserves special attention because that's another aspect where s-s preamps show advantage over tube preamps. None of reviewed tube preamplifiers, nor even my own Ayon, offered so well defined, so well differentiated and so rich bass as the AA did. It was obvious for me that the “no capacitor in the signal path” policy, and direct DC coupling between input and output did their job very well.
It translated damn well on bass differentiation on the *Eighteen** track from Pat Metheny Group's album *Offramp**. In this track the piano and the bass simultaneously start to play very fast. Both instruments have very similar timbre and you cannot hear them separately all the time. This time I got rich texture and well defined space relations between those instruments. They were not “cut-out” from the background, not really separated from each other but each of them was still a separate being on the stage and a clear separate sound source.

I also definitely liked the treble. Cymbals had their own, proper weight and were nicely differentiated one from another. There was no roughness in their sound, they were not edgy – in fact they sounded a bit like with tube preamps. Well, not so much “tube-like” as with the TAD C-600 or the Audio Research Ref5 SE, but surely I wouldn’t call them “solid-state-like.” There was this tube-like softness and silkiness but also a solid-state purity. That resulted in amazing presentation of reverberations, acoustic ambiance and so on, as these were shown in a very distinct, strong way – clearly better than by my reference preamplifier. The Ayon presents them in a bit shorter, “fatter”, thumped way. Here each sound’s decay was long, clear and really nice.
I think that credit for that goes to remarkable selectivity offered by this device and its impressive resolution, too. Obviously Matthias managed to achieve a perfect balance between these two attributes, as there is clarity and depth to the sound and all that without it being super-detailed.

Additionally, differentiation is also remarkable, comparable only with what the Soulution 720 delivered. On Previne's album, on the first track, there is a very strong double bass with a leading piano. And to the right from the center there is also Joe Pass with his guitar, but playing rather in the background, more like a rhythm guitar. With other preamplifiers and with integrated amps you can hear that too, but it takes quite some effort to follow Joe's guitar, as it blends into the background, as if its low recorded volume level, its sound not as rich as that of the piano and double bass, excluded it from listener’s perception.
With the PRE that changed dramatically – the guitar became an equal partner to the two other instruments. And it wasn't achieved by “cutting it out” from the background, nor by making it sound richer as it would mean changing what was really recorded. With the PRE guitar's timbre wasn't averaged, the edges were not blending with the background. It was as if every instrument had its own space on the stage, and was presented inside of it – of course all instruments play together, interact but they are clearly separate sound sources. And thus also the soundstage has great depth. The German device has a slight tendency to bring everything that happens on the stage a bit closer to its middle, but at the same time it delivers all “events” out of phase in a great way. So when some sounds are supposed to happen behind our head, or next to it, they simply do. The great example is Me Myself And I album, filled with out of phase effects. Any device to be able to show them right must have a great phase characteristic and low distortions. And high dynamics, too. The PRE is absolutely amazing in that aspect. Phantom images are shown around listener's head as large, solid, clear sources. It's not a “sound-cloud” around the head, these are well defined point sources of sound.

The PRE is a man-made device and as such it is subject to all man-related limitations. It is not the best preamplifier I know, but it gets very close to it, being much less expensive than the TAD or the Soulution. It is a really user-friendly device, the build and finish are ingenious, but still there some aspects of the sound that could be even better. Some of them are related to particular technology (transformers and power supply) and some are related to its designer's choices.
I already mentioned that soundstage is not as wide as that delivered by some other preamplifiers. Sound sources are located behind the speakers’ line, and not on this line, and they go wider sometimes if that's what sound engineer of particular recording intended.
Timbre-wise – I would gladly see more weight in the midrange. I said the mid-bass and midrange were fantastic and I stand by it. But somewhere in between those two sub-ranges the sound was not as rich as that delivered by the Ayon. It's not really about “richness” that I missed, but about some real substance of the sound that results in a clear picture of 3-D instrument or vocal. The PRE simplifies that a little, it operates more with timbre and tonality rather than with palpability, plasticity. The German preamplifier will not create as palpable picture between your speakers as some other, top preamplifiers will.
And there is dynamics. Here, in general, it is very good, but the Avantgarde is not a PRAT master (“peace, rhythm and time”), as it slightly slows down the presentation. I cannot state for sure that the battery power supply is responsible for that, but I heard something similar with some other battery operated devices so this might be the case. Although it might seem that some power supply limitations (source impedance) should affect only the sound of power amplifiers, I heard it with CD Players, phonostages and DACs too, and now with a linear preamplifier. Maybe there is something to it – a battery power supply might influence circuits that it supplies power to. When dealing with such devices I always hear a very smooth sound but at the same time slightly slowed down, relaxed. It doesn't mean that those devices offer poor sound – not at all! I really liked how Kraftwerk and Portishead sounded with the PRE. It was one engaging presentation showing all advantages of that device. But I also heard some very slight, but present reservation; some restrain when it came to very fast presentation of information stored in the recordings like those.

Summary
9,900 EUR makes today (at the official NBP exchange rate) 42,350 PLN, which is a lot of money. With this kind of money you could buy a small new car, or a big second hand car, or a small apartment in a small city, or pay for college. Very few people can afford that. But luxury goods are luxury goods for a reason. The PRE is one of them when it comes to build and finish, design and the sound.
If you take a look at the prices of its competitors you will find out that in comparison it is relatively inexpensive. Relatively, but that's the only comparison that makes sense. It does not offer a perfect sound, there are some sonic aspects delivered better by the Soulution 720, some by the TAD C-600, and some by my Ayon Polaris III. Nevertheless, the whole concept is so convincing, so good that you have to ask yourself – does it make sense to pay more? For people who buy nothing short of perfection the answer is simple – yes, it does. Also for those who seek particular sound characteristics offered by the other devices, it does. But for vast majority of us audiophiles the answer might be different…

Testing methodology
The item under review was compared to my reference device, the Ayon Audio Polaris III [Custom Version], and to the other preamplifiers review at the same time: the ModWright LS 36.5, the Audio Research Ref5 SE, the Soulution 720, the Octave Jubilee, plus to my Ancient Audio Lektor Air V-edition driving my Soulution 710 power amplifier directly. The PRE drove two power amps: the Soulution 710 and the Leben CS-1000P. I used Harmonix X-DC350M2R Improved-Version power cord and the preamp stood directly on a wooden shelf of the Base IV [Custom Version] rack.
I conducted an A/B test with A and B known. Music samples were 2 minutes long. I also listened to whole albums. I used balanced interconnects between the CD Player and the preamplifier and between the preamplifier and the power amplifier.

DESIGN

The Avantgarde Acoustic PRE is a preamplifier that belongs to the company's new line called XA Series. The manufacturer plans to add to this line also a D/A converter and a network audio player as well as a phonostage. Obviously, the pre+amp combination was a priority.
The PRE is a device designed from scratch by Mathias Ruff, the chief engineer of AA. When designing it Mathias made a best use of several of his patents and solutions that, although coming from already existing experience of other manufacturers and designers, create a new, unique and complete value.
The device was placed in one, solid enclosure, as one of the main assumptions was to control vibrations in the best possible way and that applied to both power supply and gain stage. He needed to use as short cabling inside as possible, including power cabling.
The PRE is a solid-state linear preamplifier, with a battery power-supply. The circuit is built on transistors and a discrete resistor ladder. There are no capacitors or DC-servo circuits in signal path. To protect other elements of this design Avantgarde came up with a very clever protection system called DC-Flow (patented, together with the volume control solution). There is only a single solid-state A-class gain stage. This a solution similar to those used by Soulution and TAD. There is no negative feedback loop.
Enclosure consists of two major parts – a 18.5 kg outside „shell”, and a 10.5 kg inner chassis covering power supply circuit (but not transistors). Altogether this builds impressive weight of 40 kg, which is really a lot for a preamplifier.

Front and back
The enclosure is made of precisely machined, cast and milled aluminum components that also work as radiators. The front panel is exchangeable but there is always an aluminum plate underneath decor plate. The front panel goes between upper and lower properly shaped plates that keep it in place. Those plates come together with nice handles.
On the right side of front panel there is a large volume control knob with nicely knurled surface. It is placed in the middle of back-lit panel with small LEDs placed in it. When volume is changed a row of LEDs show new setting and after a short while they go off except for the one indicating the present setting.
The color of back-lit changes – blue shows that “mute” mode is on; white signals that the device is drawing power from batteries; orange indicates that batteries are being charged. Toggle switches are also back-lit and their color is also important. The first toggle switch is for voltage. If it is orange back-lit, the batteries are being charged. If not, the device draws power from batteries.
Back panel proves that the PRE is a balanced device – there are XLR inputs and outputs only. There are 5 inputs and 2 outputs. There is a ground clamp, trigger outputs and knobs that allow controlling back-lit intensity.
Even though these all are linear inputs they are not the same. First three are “classic” ones with input sensitivity of 775 mV, the fourth has a sensitivity increased by 4.5 dB, and the fifth by 9 dB. The last two might be useful when one uses lower output sources (like phonostages for example).

Interior
Interior is divided into 3 parts: batteries and charger, power transformers and the preamplifier itself. The batteries are placed inside very heavy, aluminum casing – the inner case. Three power transformers charging five batteries (separately for the left and right channel and for logic circuits and back-lit) are bolted to the side wall. The preamplifier circuit is quite small; it is mounted on a single PCB. I mean each channel on a single PCB. Both channels are separated and facing each other with the back sides of the PCBs.
The signal goes from gold-plated inputs to transistors (of same kind as the ones in gain stage), that act as input buffers. Then the signal goes to relays and later to the attenuator. The latter is a patented discrete regulator, built on relays and SMD resistors that are controlled by a “logic” chip. When the user chooses specific volume (works in 48 1.5dB steps) – the signal goes to gain stage. It is a very simple design – a single transistor in a round, metal enclosure per channel. And then the signal goes to the output. Next to it there are some parallel circuits with Sanyo and Black Gate capacitor (the latter are out of production so AA bought a large stock for future use).

Remote
I need to mention the remote separately. It's heavy, made of aluminum, but that's kind of standard. What's important is its shape – it is round, with a diameter similar to that of the volume control knob, and the finish is also similar. There are three push-buttons – 2 for volume control and 1 for “mute” mode, plus there are two small “legs” that don't allow it to roll, regardless its round shape. It operates on 2 AA 1.5 V batteries.