SW1X DAC II SPX with USB Review

SW1X DAC II SPX with USB Review

The SW1X DAC is the creation of founder and chief engineer Dr. Slawa Roshkow.  I was able to speak with Dr. Roshkow whose vision appeared clear: to give back the analog character to digital recordings.  While this goal may seem simple, it is no less a daunting task.   Yet after hearing this DAC, I can firmly say that he has succeeded.  As someone who is passionate about vinyl (partially because some music is not available digitally), I think the SX1X captures a certain more inviting character that is usually associated with vinyl.  What this DAC does shouldn’t need to be quantified but experienced.

I was first intrigued by the design of SW1X when browsing reviews online.  Since the Holo May has lived in my demo system for quite some time, I was interested in what else was out there.  For those who may be unfamiliar with the design of the Holo May, it’s a non-oversampling discrete R2R DAC.  After my foray into discrete R2R with the Holo May, I wasn’t quite sure what to expect from the vintage PCM56 chips, but any reservations I had were instantly put to rest.  The output stage is a 6N6P dual triode, and the power supply features a choke and tube rectifications.  There is zero digital filtering of any kind in any of Dr. Roshkow’s DACS.  The DAC II and the rest of the catalog is a purist in all forms from input to output.

On the input side, I opted to include Dr. Roshkow’s newly designed Digital to Digital Converter (DDC). While normally the SW1X DACs only allow for SPDIF, I2S, or AES, the newly designed board allows access to a larger host of devices by including USB. While the USB doesn’t directly connect to the DAC chips, it is turned into SPDIF which is then routed back. Speaking with Dr. Roshkow, he believes SPDIF to be the best interface as it is fed directly to the DAC. Where this DDC becomes quite different from the norm is the addition of tubes. An ECC88 sits right on the input of the USB. This is used as the clock reference. While this may not seem to be the most orthodox approach, it certainly does work with the caveat of needing to reconnect the USB once everything warms up.

The first thing I noticed after warming the DAC up was the quality of the sound.  As with listening to a vinyl record, the room fills with sound.  There is a cohesiveness to the sound that envelops every space, whether listening on speakers or through headphones.  There’s a sort of tonal density that strikes me every time I listen to the DAC.  All of the sound is filled in.  It makes the music come alive and breathes into it emotion and life.  I think this is where the DAC really shines.  I think this comes from a combination of a few things:

1. The soundstage is very naturally laid out. The instruments seem effortless in their presentation. All instruments don’t seem jammed up in the front or unnaturally wide. Everything is in its place.
2. Incredibly dynamic bass. While remaining tight and controlled, the bass feels more dynamic and impactful than other DACs I’ve heard.
3. Transients (as with a lot of tube-based devices) seem to really jump out at you.

The next thing that struck me is that while people usually have the bias that tubes make things sound warm or muddy, the DAC II is surprisingly neutral and uncolored from what one would expect. I will admit even my own bias got the best of me here. I was expecting a rich warm sounding DAC. What I got was a surprisingly neutral yet organic sound. It still has that amazing tube character which always seems to make things feel more tangible and real but without much of the usual coloration associated. The other thing I was not expecting is that it is quite fast and resolving. SW1X’s implementation of the vintage chips keeps up in terms of resolution with almost any of the modern DACs I’ve heard. The transients are quick and snappy, and with them already being quite dynamic with this DAC makes for an amazing presentation.

Adding all this together made for one of the most engaging DACs I’ve heard yet. It is captivating, it draws you in, and it doesn’t let you go. If you want a DAC to sound as engaging as your records, you would be hard pressed to find it elsewhere. Dr. Roshkow and the team at SW1X have done an amazing job at breathing new life into digital playback.

Get yours here!