 “USB DAC” is a category conceived by Wavelength Audio. In reality it just a classic digital to analog converter equipped with an USB digital input and optimized to be used with a computer. Now because we tested the model Brick made by this company, we know that Wavelength is not just another ‘run of the mill’ manufacturer, who felt the tide of the market, put a DAC together in his garage, and announced to the world its brilliance. The most pronounced difference, working to Wavelength advantage is the fantastic support: on the company web pages devoted to those devices (HERE) we will find detailed instructions on how to turn our computer into a valuable sound source, and what to do, to make it have optimal working conditions – sound wise. And this is not so easy – neither Mac’s nor PC are sound-friendly devices, and some tweaking must be done to force them into that role. )
The tested unit, the model Cosecant v3, which first version was presented in 2004 during the CES, is more expensive than the Brick and brings some new things. First of all we get a new converter chip – earlier it was a 16-bit Philips (without an output digital filter), now we get a 24-bit (96kHz) Wolfson DAC – what allows for using hi resolution files. But this is by far not all – the converter is mounted on a separate PCB, called Numerator, and this can be exchange to a module identical as to the one in the Brick, named Transcendental. We received both for testing. After that we’ve got a tube output stage, here with a NOS ECC86 double triode, coupled to the RCA sockets by means of transformers, not capacitors. And finally – inside we got small switches, with which we can set the output as a balanced output, meaning a “floaing” ground (although this is still an RCA) or unbalanced. “Stereophile’s” measurements made during the test of this DAC (Art Dudley, Wavelenght Cosecant v3, „Stereophile”, June 2009, Viol. 32, No.6, s. 77-85) showed clearly, that the latter setting produces less noise. And this I can confirm with my listening tests – high resolution recordings sounded clearer, the instruments were better articulated, when the switches were set to unbalanced. We tested earlier: )
Recordings used for testing: SOUND )
Cosecant is a completely different story than the Brick. Its tonal balance is set much lower, and timbres are warmer. This is why I will not tell unequivocally, that this is a better converter than the Brick. In many aspects it brings a nicer, more relaxing sound, having nothing in common with “digital” sound, computers or networks. As if its creators wanted to show, that the common belief about digital carriers is completely wrong; that the glassiness, brightening and clinical sound are just distortion, not the sound itself written using zeros and ones. You have to pay a certain price for it, about that in a moment, but if that was really the purpose, then they succeeded fully. And one more thing – although tonally and resolution wise, I like the Brick better, plugging the Transcendental card (the same setup as in the Brick, no oversampling) into the Cosecant, in place of the Numerik (24/96), was a step backwards, what confirms, that the output stage of the Cosecant is better. So why does the Brick not give the field? – I do not know for sure, you just have to compare those individually and decide, which one is the one we are looking for. )
To test this thoroughly I made a set of different comparisons, that had to show, how the Wavelength behaves with different kinds of recordings, and how those stand against their versions on other carriers. The tests were as follows: the reference one on the left and the Cosecant on the right side (with one exception). )
Based on this we can describe the sound as warm, with the accent put on lower midrange. Switching to my Prime (Ancient Audio Lektor Prime, CD), Luxman (D-08, SACD) or McIntosha (MCD-1000+MDA-1000, SACD), but also – and that came as a surprise – to a turntable (Avid Acutus + SME Series IV) everything became closer, more rounded and fuller. Yes – besides vinyl – all the remaining sound sources had “thinner” midrange, when compared directly. This is the element, that was most important when comparing my Prime with Reimyo and was mainly responsible for the significant advantage of the latter. The American DAC had a very similar timbre, maybe a bit lower, but with similarly saturated vocals, big contrabass, etc. The first planes were close to the listener, much closer than with all my reference devices, and closer than with the Brick. This is why everything seemed so intimate, emotionally close and having no digital hoarseness. Like I said – this is a big achievement, not only with regard to computer environment, but for a digital source in general. Only SACD discs played from top players I had for comparison showed, that it can be brought further, that sound can be played smooth without warming anything. The same thing was with vinyl, which gave also best stereophony and resolution in this comparison. )
And this last element is in my opinion the victim of fantastic timbre and palpability, that characterize the Cosecant. The resolution of the unit with 16/44.1 recordings was rather mediocre, and not only the edges, but also the structure of the instruments were presented better with the Brick – for as far as I remember. This is not a simple “silting” of the sound, like with some tube amplifiers, but rather a withdrawal of some of the information, with priority given to sound saturation. It was much better with hi-res. Here we did get much information and still the same beautiful timbre. Some problem were recordings ripped from DVD-A discs, like Love The Beatles. This was a 24/96 recording, used also for pressing the vinyl. And still vinyl was much better than the digital sound. Because this happened a few more times, except with Classic Records, this must be attributed to some kind of protections or watermarks in DVD-A audio signal. Recordings FLAC 24/96 and 24/88,2 from Linn Records had a similar timbre, but their resolution and sound stage did not have the shortcomings of DVD-A copies. )
So that is how this DAC performs. For many audiophiles this can be bulls-eye, because while it is not neutral sound, it does fulfill the basic requirements of an audio device – it provides joy from listening, and that in such a demanding environment, like a computer. This is absolutely rare. But because the Brick delivered so well with 16/44.1 recordings, you should give them a head-to-head comparison before deciding. And the Brick is one of the best USB DACs on the market – in my opinion – and even the very good, also in that aspect, Benchmark DAC1 USB did not provide such a good sound with signal coming from a computer. And we learned, that it can be completely blown listening to DacMagic Cambridge Audio - a splendid DAC, inexpensive, well equipped, but working from USB it gives at most mediocre sound. On this background, the Brick, as well as the Cosecant, look like heroes. Those are the best DACs of that class, that I know. Yes, the Cosecant gives a more saturated, closer sound, but it lacks extension on both ends of the spectrum, as delivered by the Brick. And this is good – because it leaves us some choice. DESCRIPTION )
Cosecant v3 is the third version of this device. It can be classified as a classic DAC, but it has only a single USB input and is optimized for working with computers. The digital to analog converter Wavelength Audio Cosecant USB DAC is beautifully made. It stands out from the Brick, Cambridge Audio or even Benchmark. It has similar dimensions to the Brick, but there is a tube sticking out of it – a double triode 6GM8 (ECC86, here coming from General Electric), covered with an acrylic plate. Changing the tube is hence more difficult, but this has not a very big issue, as this is not done every day. The top and bottom plate are made from scratched aluminum in natural color, the front from a wooden element, and all the remaining sides from black varnished steel. The unit is supported on three feet. On the back we have splendid RCA sockets with the analog output, an USB input type B (rectangle type), socket for the external power supply and a green LED. The power supply is mounted in a small, but very solid aluminum enclosure. The cable is very thin, and does not make a lasting impression. To increase the lifespan of the tube, the digital circuits are powered on all the time, but the analog section is switched on only, when signal is present on the USB port. A small, white LED is lit when this happens. )
Inside we have two PCBs – the main one, with the USB controller TAS1020B and a smaller one, with the Wolfson Microelectronics WM8716 converter on it. The controller was modified by Wavelength people to work in asynchronous mode (Asynchronous Mode USB Audio). This means, that the signal is clocked not by the computer clock, but by and internal clock, mounted near the controller. This allowed to minimize jitter. There are not many elements on the PCBs, but those that are, are from very high quality: metalized resistors, Wima polypropylene capacitors, Rubycon Black Gate electrolytic capacitors. On output we have the mentioned tube, coupled to the output RCAs by means of transformers. Behind those there are also chokes.
CDs FROM JAPAN  |
||||
| © Copyright HIGH Fidelity 2009, Created by B |
