Calling your company White Bird Amplification seems to be a good move. Name is catchy, and it's original. But one could realize that there is even more behind that name when he finds out that the owner and designer's name is Bocianek (might be translated as little stork), Piotr Bocianek, to be clear.
Although you can't tell it from company's name but it makes only one kind of products – headphone amplifiers. The range starts with costing 700 PLN HPA-03 Reference, and ends with Grand Twin PRO with 300B tubes and a display (at 2700 PLN), and all of them are headphone amps.
That's how I found out about this manufacturer – one of our Readers (thank you again!), headphone lover obviously, wrote to me asking if I had ever listened to any of Mr Piotr's amps. I had not, but I immediately used this opportunity and send and email. Not that I received an amplifier immediately – I had to wait a while, but here it is, and that's what matters. I had to wait for it because I was going to receive a completely new model; during my test it still wasn't even presented on the manufacturer's website. Plus each copy is made upon order only – it's a present flagship, that will soon be joined by another model - Virtus 300B (with 300B tubes obviously). I've planned its test for September, „Polish” issue of HighFidelity.

In this test I'm going to take a closer look at Virtus-01. This amplifier is build around KT88 power tubes and a single double triode 6N6P in the input. The latter reminds me a lot of 6H30P „super-tube”. As Mr Bocianek explained Virtus might work with some other tubes as well – ECC85, E88CC, 6N23P, and even 6N2P in the input stage. But according to him the sound gets more „metallic” with one of those. It is also possible to use KT66 or EL34 in output stage without having to change bias setting.
The build quality of tested amplifier is really very good. Enclosure is made of granite slates, nicely matched and joined together and a special front panel – it's acrylic with a printed foil fixed to its inner side. Tubes are inserted via cut-outs in top plate – I received Electro-Harmonix KT88EH together with the device, but I tried it also with Ayon Audio KT88sx (it's a special version of Shuguang tubes, read more HERE). The tube in the input stage is a Russian NOS. Pot is an Alps, and inside we can find WIMA and Nichicon Muse capacitors. Samsung capacitors were chosen for power supply as the best sounding ones. Designer used metalized resistors with 2% tolerance.
As I already said build quality is very good although you can tell it is a hand-made product. Virtus-01 is available in two finish versions – one with steel-aluminum enclosure at 3500 PLN and the other with a granite one, significantly more expensive at 5000 PLN. I received the latter for my test.

SOUND

Recordings used during test (selection):

• Air, Love 2, Archeology/Virgin/EMI/The Vinyl Factory, 53361, 2 x 200 g LP (2009).
• Audiofeels, Uncovered, Penguin Records, 5865033, CD (2009).
• Bill Evans, Selections from: Bill Evans Live at Top of The Gate, Resonance Records, blue vax 10”, Limited Edition No. 270, 180 g LP (2012).
• Chet Baker Quartet, Chet Baker Quartet feat. Dick Twardick, Barclay Disques/Sam Records, Limited Edition, 180 g LP (1955/2011).
• Deep Purple, Perfect Stranger, Polygram Records/Polydor K.K. Japan, 25MM 0401, LP (1984).
• Diorama, Cubed Deluxe Edition, Accession Records, A 114, 2 x CD (2010); review HERE .
• Kraftwerk, Techno Pop, Capital Records/KlingKlang/Mute Records, STUMM 308, digital master, 180 g LP (1986/2009); review HERE.
• Me Myself And I, Do Not Cover, Creative Music, 005, CD (2012).
• Nat „King” Cole, Just One Of Those Things, Capitol/S&P Records, Limited Edition: 0886, 71882-1, 180 g LP (2004).
• Suzanne Vega, Close-Up, Vol 1. Love Songs, Amanuensis Productions/Cooking Vinyl, COOKCD521, CD (2010).
• The Beatles, Revolver, Apple/Parlophone/Toshiba-EMI, TOCP-51124, CD (1966/2000).
• Tommy Dorsey, This is Tommy Dorsey, RCA Records, VPM-6038, 2 x Dynagroove LP (1971).
• Wes Montgomery All-Stars, A good git-together, Lone Hill Jazz, LHJ10133, CD (2004).
• Władysław Komendarek, Przestrzenie przeszło¶ci, Metal Mind Productions, MMP CD 0697 DGD, 2 x CD (2011).

Japanese issues available at

Virtus-01 with Electro-Harmonix tubes
I have to say that it took me some time to find a proper „key” for this headphone amplifier. At first I listened to it with AMG Viella12 turntable and Manley Chinook phonostage as a source and I found this sound to be bit too bright, too thin. But to be clear – except for proper tonal balance everything I would expect from a high-end headphone amplifier was there: it offered great resolution, it was revealing, there was great spacing (I mean great headphone spacing) and amazing dynamics, in macro scale above all. And while some modifications to tonal balance are clearly audible definitely influencing the sound of this amplifier, when I changed the source for Ancient Audio Lektor AIR V-edition CD Player and I decided to put White Bird on Acoustic Revive TB38 platform (it's a smaller version of RST-38, dedicated for power distributors and small amplifiers) I finally was presented with what I expected from very beginning – pure MUSIC.
Virtus-01 delivered very „mature” sound. It sounded somehow similar with every headphones I used with it. And while with each pair some characteristic features of the sound of each of them were audible, but amplifier, while showing them, did not emphasize them, it didn't chose „either or”. To give you some hints what to try Virtus-01 with I would go with: HiFiMAN HE-500, Beyerdynamic DT990 PRO (Vintage) and Sennheiser HD800. If I had to narrow it down even more I would say: HiFiMAN and Beyerdynamic, which proves how capable this amplifier is. HE-500 are planar magnetic headphones quite difficult to drive, and high-impedance Beyerdynamic also don't work well with all amps. With ultra-difficult to drive top model HiFiMAN HE-6 it wasn't bad either. I had to set volume to the maximum but it did not result with any distortions or compression in the sound. It says a lot about power supply's stability and power tubes capabilities.

But in the end I was left with two pairs of headphones – HE-500 and DT990 PRO (Vintage). The „vintage” addition is mine, not manufacturer's, and I use it to emphasize that my pair was made long time ago and might not be identical to same high-impedance model manufactured at present. These are one of the most interesting headphones that have been available on the market for many years. Back in the days these were one of the best ones used in many studios along with its closed-back version DT770 PRO. And while since than many other great headphones appeared on the market from AKG, Sennheiser, and also other models of Beyerdynamic, it seems that DT-990 PRO has still a lot to offer.
I took them out from a drawer after a long, long time, when testing Funk Tonstudiotechnik LAP-2.V3, and they sounded amazingly well. But years in a drawer made their marks on pads and capsules.

And that's one thing that we usually don't discuss in our tests, because it's not possible unless you posses some device for a longer time – support, how manufacturer treats their customers. Beyerdynamic obviously takes really good care about their customers. I contacted Polish distributor, paid for my order and 2 days later I received new capsules, ear-pads and headband padding. That's some customer support!!

Sorry for the digression but since such a great customer service is not so common these days it is surely worth mentioning. Beyerdynamic with Virtus-01 sounded remarkably and same goes for HiFiMAN. In both cases it was about rich midrange and bass, and great resolution of not excessively strong treble. For there is an emphasize on 800 Hz – 1 kHz range, and this part of range carries upper parts of vocals. It's still midrange but it is its upper part and it is emphasized by amplifier, which is not so obvious from the very first moment we start listening. First thing that catches attention is total lack of any hum or noise. It is amazingly quiet tube amplifier. My own Leben, that betters Virtus-01 in every other aspect, buzzes like a humble-bee comparing to Polish amp. After couple of days with White Bird, my Leben started to get on my nerves with its buzzing. As you might easily find in the web many people tried to do something with their Lebens with many different upgrades. The best effects I know of were achieved by Mr Eugeniusz Czyżewski from Linear Audio Research (read more HERE), but even he couldn't beat Leben design's limitations. The bigger respect one has to have for Mr Bocianek because when you put headphones plugged to White Bird amp without playing any music there will be nothing that you hear, just thick, black „silence”.

When I finally played some music what I heard was a very orderly, sophisticated sound. I mentioned treble already – it was remarkably crisp, vibrant, rich and with great resolution no matter which headphones I used. It wasn't exaggerated, coarse nor grainy at all. The last feature I appreciated mainly with Beyerdynamics, that confirmed in this way their „cult” status. The other frequency range extreme showed same great resolution, and was also very tuneful. But I couldn't say that there was a lot of bass. That's why HiFiMAN sounded so well with this amplifier – these headphones emphasize part of the range below 200 Hz, adding to the sound something like „air pressure”. So there is not a lot of bass but there is a really nice grip and weight. One might seem to contradict another – that's what we usually get from loudspeakers, if there is not too much bass, and there is nice grip than there is no proper weight, sound is too „light”, dry. But not here. To be honest I did not feel that there was something missing, I just felt like adding some bass (I wrote about it some time ago, describing how a need of „natural sound” beats sometimes a need of „neutral sound” - that's how I explained why I liked using „Bass Booost” feature with Leben). When I finally got used to Virtus-01 sound I could keep on listening.
And from this moment on I truly enjoyed every piece of music I listened to. It was during the time of this test that I bought Komendarek's double album, and I also got for my birthdays a new album Me, Myself And I (I can't help it – I think that this album together with Audiofeels are good examples proving that something good might come from TV shows like Idol, Must Be The Music and so on, after all). Both albums sounded extremely rich. It was a deep, very emotional sound, with great soundstage depth, lots of details – I really enjoyed what I heard.

Any downsides you ask? Aren't there always some? First of all the tonal balance modification I mentioned before. Because of it one needs to chose the rest of the system – source, cables – very carefully. So a listening session in your own system is a must before you buy it. The second, and last, downside – Virtus-01 does not render precise 3D images. The phantom images, instruments, vocal are shown „together”, without clear separation, without showing separate „musical events” on the stage. And maybe, but only maybe, I would prefer a bit richer lower bass. But these are my personal preferences, as this amplifier seems to keep proper proportions between bass and the rest of the range. So you might not share my opinion about that aspect of sound.

Virtus-01 with Ayon Audio tubes
Tube rolling brought some benefits to the sound but also proved that many basic features of White Bird amp would stay the same regardless what tubes were used. Ayon tubes improved the depth of the sound, its resolution and richness. Now the sound was even more sophisticated, I could feel it even more in my guts. The extend of the changes to the sound was noticeable but it wasn't a game changer. And in fact I really appreciated improvements achieved with Ayon's tubes when I got back to „standard” Electro-Harmonix tubes. It became even clearer that Ayon's tubes gave me more depth, richness and sophistication. Sound was damn good with them. Listening session with these tubes confirmed what I already knew – slight emphasize on part of midrange and great grip in bass range – these were fantastic qualities of Polish headphone amplifier.
Virtus-01 is a very „mature” product. It is one of the best headphone amplifiers I know. There is still some space for improvement here, but when you listen to it you don't really feel like those improvements are necessary.

Test methodology
I compared this amplifier with three others: Leben CS-300 SX [Custom Version], Synergy HiFi 6F3 and Triode TRV-A300SER. I used following headphones during test: HiFiMan HE-500, Sennheiser HD800, AKG K701 and Beyerdynamic DT-990 PRO (Vintage). I used HiFiMAN and Sennheiser with Entreq Konstantin 2010 cable. Amplifier was placed on Acoustic Revive TB-38 platform. I used Purist Audio Design Corvus interconnects.
I did an AB tests, with A and B known. I used 2 min music samples, but I listened to whole albums too. Apart from using my Lektor AIR V-edition CD Player as a main source for this test, I used also AMG Viella12 turntable with Benz-Micro LP cartridge and Manley Chinook phonostage (both on loan for tests, tests to be published in „High Fidelity” – No. 98, June 2012).

DESCRIPTION

Virtus-01 is a tube headphone amplifier with solid-state power supply. The enclosure is build of granite slates (top and sides), acrylic front, plastic back and aluminum bottom. There a volume control knob on the front with red power LED above it, there is also mechanical on/off switch and headphone socket. On the back panel there are two pairs of RCA inputs and power inlet. On the top cover there is a nice brass plaquette with manufacturer's logo, and gold plated rings around cut-outs for tubes.

Unfortunately I could not get this amp opened – it is made in such a way that I simply couldn't risk damaging it. So I can tell you only what I managed to see through tube cut-outs and on what manufacturer told me about. I could see that circuits were placed on few PCBs and that there were two separate power transformers. I couldn't see output transformers so it seemed it was an OTL design with capacitors in output stage. Volume control is managed by Alps pot. All internal connections were made with pure copper.