_{All photos by Tom Gibbs.
Prices are listed in US$.}

Over ten years ago, I started my journey in digital audio streaming with an original High Resolution Technologies (HRT) music streamer—which was a fairly unobtrusive little device aimed primarily at novices in computer-based audio. But over the course of several years, each successive model in the HRT line incorporated more robust circuitry and support for higher streaming rates. The last HRT model I evaluated, the Streamer HD, convinced me that in my relatively pedestrian audio system, it was as much as I’d probably ever need for true streaming happiness. But then I got “the email” that turned my streaming digital audio world on its head!

The email came from Dalibor Kasac, who was with Euphony Audio in Croatia—they’re the guys who make the Euphony Stylus operating system and the Summus streaming/server setup that’s been the focal point of my digital audio system for the last five years. At the time the email arrived, I didn’t have a clue who they were, nor was I keen to take Dalibor up on his offer to review the Stylus, especially since I’d just sold my house and was living in my brother’s basement for the next nine months, with all my stereo equipment packed away in a storage locker while my new home was being built. But no matter how many ways I tried to explain the situation to Dalibor, he wouldn’t take no for an answer, and for some insane reason, he seemed to think that I was the guy who would help introduce Euphony Audio to the masses. I was reasonably convinced that Dalibor was insane, and besides—I was this relative nobody who’d barely dipped his toes into digital streaming. Still, we struck an agreement that as soon as I was set up in the new place, we’d get back in touch and go over the details.

A lot transpired over the next year or so. It took nine months to build the house, but it took forever to actually get to the point where setting up the stereo was finally a priority in the move-in process. When Dalibor and I eventually reconnected, Euphony’s Stylus was now no longer just an operating system you loaded on to your own computer—it was a turnkey, plug-and-play hardware system, which made the deal even more effortless for me to embrace. Over the years, Stylus has gone through several iterations and upgrades, and has evolved into a first-class high-end solution for all your digital needs, including streaming, server and library management, and the crème de la crème: a world-class music player. And it’s a very refined setup, such that three years ago, I no longer felt the need to continue my Roon subscription—besides, the sound quality of Euphony’s music player completely smoked Roon! I upgraded to Stylus 4.0 last year, and it’s a major improvement in terms of the appearance of an already great GUI (Graphical User Interface) and by offering several key upgrades that have lifted the sound quality to an impressive level of goodness. My upgrade to Stylus 4.0 also included a subscription to Mozzaik upsampler—more about that in a bit!

Over the years, Dalibor and I have consistently stayed in touch, and Euphony has also become a distributor for a range of high-end audio equipment from manufacturers mostly located in the EU. Through them, I evaluated Germany’s Naiu Laboratories Ella power amplifier, a top performer that’s been driving the loudspeakers in my digital source system for a couple of years now. Dalibor and I may go months at a time without contact, followed by furious flurries of activity. That happened last year, when he reached out to me to detail Euphony’s experiences with a new delta-sigma DAC from Topping, the E70 Velvet, which, based on its chip configuration, could be used as a DSD-direct DAC. Not long after that, Dalibor and his business partner, Robert Devcic, discovered that Topping’s then newest DAC, the bargain-priced E30 II ($150), bettered the performance of the E70 Velvet, and by a wide margin. They’d been experimenting on it for months and had reached the conclusion that it was a giant killer.

About ten days ago, Dalibor again reached out to me via email to follow up on his enthusiasm for their continued good experiences with the Topping E30 II DAC, with particular emphasis on its performance as a 1-bit DSD-direct DAC, in a new and exciting implementation. I grabbed one from Amazon, and I’m completely gobsmacked by how very good this little DAC is, especially considering its miniscule price tag. But the real shocker for me came when Dalibor asked me to disassemble my current digital streaming setup—including half the Euphony setup I’d been enjoying for years.

A Big Step Backwards…Or So It Seemed Likely!

That system, which had held the status quo in my home for several years, featured the dual-box Euphony Summus/Endpoint setup, which included a pair of Intel NUC mini-computers housed in custom Akasa cases. Of the two, the Summus was the higher-powered unit (Intel Core i7), and provided the music server/library organizer/music player function; the Endpoint (Intel Core i3) was nearly identical in appearance, and predominantly functioned as the streamer. Dalibor and Robert always insisted that separating the streaming function to a second unit would result in a step up in sound quality, and that has always been my experience. The digital stream would then travel, via a superior i²S connection, to the Gustard X26 Pro DAC, which was also connected to a Gustard C18 clock via a BNC digital cable. It’s a system I agonized over, especially with regard to matching everything with the right digital cables from Audio Art Cable, Oyaide, and Sommer. I honestly felt it could hold its own against digital source systems of a much higher pedigree, and I was perfectly happy with the system’s sound quality.

During a WhatsApp call, Dalibor instructed me on the changes that needed to be made to my system. First, I’d need to access the BIOS of the Euphony Summus device, which proved to be trickier than I remembered. The Euphony OS runs on a highly modified version of Linux, which is a different animal than Windows or Mac, and I needed a USB keyboard and monitor to access the system BIOS to make the changes that would allow Euphony Summus to have the processing performance boost it would need for the new configuration. Once that was accomplished, I would then disconnect and remove the Euphony Endpoint, and follow that process with the removal of both Gustard components. Whoah! In one fell swoop, I was losing the advantage of a separated streaming device, losing the superior i²S cable and connection, and losing what I considered to be a world-beating DAC in the Gustard X26 Pro and the C18 clock unit. I’d then connect the new Topping E30 II DAC with the Oyaide USB cable to the Euphony Summus, and activate Mozzaik upsampler in the Summus’s menu settings.

The Mozzaik upsampler software plugin comes from Mozzaik Audio, another EU company that offers both hardware and software solutions for high-end audio. The software converts all bit-and-sample rates of PCM to DSD64 (SACD quality) for exclusive DSD playback through your DAC. Mozzaik’s lengthy development process abandoned traditional filter models, and created a highly specialized DSD modulator that incorporates proprietary upsampling filters. The upsampler’s designers fine-tuned their proprietary filters by ear and enlisted the assistance of listening panels to help in the process. Euphony’s Devcic participated in the listening panels and was able to secure licensing rights for the upsampler’s use in Euphony’s Stylus 4.0 release in 2022. Dalibor graciously granted me a one-year subscription to the Mozzaik upsampler for evaluation in my system.

In effect, what Dalibor was asking me to do was remove nearly $8000 in equipment from my system, and replace it with a DAC only slightly larger than a deck of cards that retails for $150. Adding insult to injury, I’d also be removing the i²S connection and replacing it with what I regarded as an inferior connection—USB. Sensing my lack of enthusiasm on that front, Dalibor assured me that the USB connection has made incredible strides in recent years, with enhanced compatibility and improved sound quality that’s virtually on par with the über transparent i²S. Turns out, the Euphony Summus was absolutely capable of doing the heavy lifting—even minus the Euphony Endpoint—and that $150 Topping DAC was a wunderkind among reasonably-priced digital to analog converters! On Dalibor’s recommendation, I also ordered a USB battery from eBay ($25) to power the DAC; Dalibor says taking the DAC “off the grid” moves it to a different level of transparency and sense of effortlessness.

The Topping E30 II DAC, In Combination With The Mozzaik Upsampler

The E30 II is Topping’s second DAC in their line to feature new production AKM chips. It differs from the previous E70 Velvet DAC in that it utilizes a pair of AKM AK4493S chips—one for each channel. The E70 Velvet used a single AK4499EX chip, but significant advances have been made since, and the pair of AK4493S chips used in the E30 II offers an improved level of performance by separating the transfer function into a dual-mono setup. As with the E70 Velvet, the E30 II also incorporates what AKM refers to as their “Velvetsound” technology, where DSD playback can be configured to avoid the dreaded delta-sigma process, where both PCM and DSD are combined in the DAC’s throughput, which ultimately colours the sound of everything that emerges, especially that of DSD files. Dalibor told me that while he and Robert were initially impressed with the sound of the E70 Velvet, they’ve come to appreciate the more modestly priced E30 II to an even greater degree. The only other major difference in functionality is that the E30 II has no balanced outputs, which in no way was a deal breaker for me. At $150, my only point of indecision came when I had to decide what colour to get it in—black, silver, red, or blue. I really wanted a red one, but I could get the black one in two days from Amazon versus ten days for any other color, so that made the decision easy for me.

Here’s where the Mozzaik upsampler comes into the picture. With Devcic having been an active participant in its developmental trials, and with almost two years of evaluation of the Mozzaik software in combination with Euphony equipment, he and Dalibor are impressed with its capabilities, and especially its musicality. And it makes complete sense in this implementation to convert everything to DSD. Other manufacturers—PS Audio, for example—converts everything to DSD64 in their top-of-the-line DirectStream DAC. And by combining the Mozzaik upsampler with the Topping E30 II, and converting everything to DSD, you bypass the delta-sigma function, making the E30 II a 1-bit DSD-direct DAC. When Dalibor had me set up the Euphony Summus for enhanced processing power, that transformation was essential to its ability to transcode the PCM files to DSD64 prior to them being sent to the Topping E30 II.

There’s a specific setup sequence in the Topping E30 II’s menu to guarantee DSD-direct playback; the E30 II has volume control capability, and you have to defeat that, which sets it to DAC-only mode. Otherwise, using the digital volume control sends everything through the delta-sigma modulation. In normal use, the Mozzaik transcode process is fairly effortless; in the Summus’ setup menu, you simply select the upsampling mode, and everything gets transcoded to DSD64. That said, my music server has more than 400 DSD albums on it, and you don’t want to transcode existing DSD files. So when playing PCM files, click upsampling on, then off again when playing native DSD files—it’s a surprisingly fluid process, with no hiccups when switching between modes. Dalibor, who isn’t a fan of DXD files, which are the highest resolution PCM files that currently exist, feels that transcoding them to DSD greatly improves their musicality.

So How Does The New System Sound?

My evaluation was done using the system that features PS Audio’s Stellar GainCell preamplifier, the Naiu Labs Ella power amp, and a pair of Magneplanar LRS loudspeakers used with two Vanguard Caldera 10 subwoofers. I felt I needed to give the Topping E30 II several days to burn in for best playback results, but when I started listening critically, I was seriously impressed with what I was hearing from a $150 DAC, especially compared to my experiences with the other, much more expensive equipment in the playback chain. I mean, hearing the Topping E70 Velvet was originally an eye-opener last year, but the E30 II provides a much more organic sound quality than the Velvet, that approaches that of good analogue reproduction. I played tons of native DSD files I was intimately familiar with, and they were all rendered with increased clarity and transparency, with improved imaging, and with a much more liquid midrange and highs that simply sparkled. Compared to my previous digital source system with either the E70 Velvet or Gustard X26 Pro DACs, the sound of DSD files was now mind-bogglingly good. I’ve always been a proponent of great sound on a budget, but the Topping E30 II takes that approach to a new low. Low price, that is!

Via the Mozzaik upsampler, the gains achieved from transcoding PCM files of every rate to DSD64 were remarkable. I was shocked by how good my CD-quality rips sounded when compared to the delta-sigma-processed alternative, and I felt that the transcoded PCM files of higher-than-CD resolution were even better! CD-quality rips that perhaps had sounded less than fully fleshed-out now were presented with a greater sense of realism; there was a more pronounced stereo image, and analogous to my playback of native DSD files, the transcoded PCM playback sounded much more… analogue. I have a playlist of about 100 tunes across all genres on my server, a mix of PCM and DSD files I typically use for equipment evaluations. Since the arrival of the Topping E30 II and Mozzaik upsampler, I’ve broken it apart into two separate playlists, one for PCM files and another for DSD. This allows for easy continuous playback of the tunes on the respective playlists without the need to frequently switch between transcode modes. I’ve even been listening to a ton of old stuff—mostly CD rips—that I hardly ever listened to anymore, and their sound quality is soooo much better than I remembered it being on the old system.

I’ve been closely associated with PS Audio’s equipment for years—I own the company’s Stellar preamp, Stellar phono preamp, and a pair of M700 amplifiers. And I’ve had a fairly constant awareness of the raves for their DirectStream DAC, which, of course, converts everything to DSD prior to playback. But its $8000 price tag has always been prohibitively expensive for me. I constantly thought about the potential benefits of converting PCM to DSD, and as a years-long Roon user, I experimented at some length with Roon’s built-in upsampler, which I found to be half-baked at best, yielding less than satisfactory results. Of course, the less-than-stellar complement of equipment I was using at the time could very well have been a contributing factor, but my current experiences with the Topping E30 II and Mozzaik upsampler have bolstered my opinion of PCM to DSD conversion.

Even More Goodness To Come!

Euphony is in the process of building a statement, single-box streaming solution that will include dual motherboards to separate the streaming and server functions as in their dual-box Summus/Endpoint setup. The new system will also include the latest implementation of Mozzaik’s software, which will upsample everything to DSD128. In my experience, higher DSD rates are better, and always result in digital sound that’s closer to that elusive analogue-like absolute sound. More to come as the development of the new machine evolves over the next six months or so. I’m awaiting its arrival with intense excitement!

In the meantime, the overachieving Topping E30 ll is keeping me very happy.