Whilst awaiting the second power umbilical and tech support on my iMac issue, I received this note from Gunhee: "When X7-DAC MQA and X7-DDC Femto share our Clean Power supply and USB signal enters the X7-DDC Femto, USB noise transmits through the power supply to the DAC. This seems to affect sound quality. So we already have feedback of better sound when one powers the X7-DDC Femto from its DC adapter not the Clean Power. Some of our customers thus buy two Clean Power units to drive our DAC and DDC separately." I pointed out that if true, would this not undermine the Clean Power concept of power isolation? There was isolation from the AC power grid but not isolation between two components sharing the same DC supply? Weren't customers entitled to think the PSU design a bit flawed?

"I asked our planner about his intention for the Clean Power. He explained that the X7-DAC MQA, X7-DDC Femto and Clean Power are intended as individual pairs not a full combo. Like you I asked why our two Clean Power outputs aren't isolated from each other. To implement this at our price just wasn't feasible. However, with isolated signal like your transformer-coupled S/PDIF, using both terminals of the Clean Power supply will be superior to using one power adapter." Until I had two umbilicals to retest USB and S/PDIF, I couldn't weigh in. But Gunhee would "be grateful if I could get your feedback on it". When was the last time a maker had pointed me at a potential design conflict? I couldn't remember. He also agreed that Soundcat still had to tweak their communications. I'd waited 2+ weeks by then without hearing back on the iMac issue. "I think this late feedback is something our company must fix now. We just don't have enough people here who specialize in hifi products like JAVS."

Once the second umbilical arrived, I returned to the upstairs S/PDIF SD card source. Upgrading the DDC to Clean Power—the DAC was already on it—factored in particular on items like the piano of Rubalcaba. Take his bridge at 2'14". It's from his Minione album with Polish songstress Anna Maria Jopek. If you're sensitive to what I call tinkling, you'd notice that with the DDC on the bigger PSU, the higher ivories had less bell-like tinkle and more tone-wood redolence. This was a subtle shift and your call entirely. If you own these three components, you're in charge whether and where to use a wall wart. You'll have all the pieces to explore all the permutations. If you prefer more edge/bite, forget the batteries. If you want to retain some sharpness, put only the DDC on the Clean Power. If you want even less sharpness, put the DAC on it, the DDC on the wall wart. For maximal reduction of etch and the biggest emergence of relaxation and ease with S/PDIF, hang both off the upgraded PSU. That's the most organic and spacious sound which combines top resolution with top naturalness.

On my Win7/64 USB source whose system isn't dialed for top resolution but listening pleasure, I heard no alleged signal degradation, just the now familiar benefits when both DDC + DAC ran off the battery supply with ultracaps. To track presumptive gremlins on that score, I needed to throw more resolution at it. That meant our big iMac system. Very much unlike Gunhee's customer feedback, I heard an unexpectedly significant advantage from having both JAVS decks on the same Clean Power supply. The tunes came off smoother and mellower. This had all the hallmarks of the upstairs experiments, just with a bigger with/without delta. I saw no need for a second big power supply to turn my Soundcat trio into a quartet. I couldn't duplicate what the other customers had reported to JAVS.

Conclusion. As was the previously reviewed/awarded X7-DAC MQA, the follow-on JAVS X7-DDC Femto is a fine example of modern digital engineering for quasi prosumers. Those are clients who apply more 'professional' standards to their hobby such as reclocking digital data by external clock generator. That's similar to how recording engineers do it. Such consumers get more serious about advanced hardware and associated sonic refinements. Just as they are next-gen products, there are next-step products. They go extra steps beyond the basics. As it happens, even very non-basic D/A converters remain guilty of still benefiting from devices like today's. That redefines this next step as a discrete second stage. It completes the first stage of the DAC. Let's leave the full tech rationale of two-stage clocking plus sample-rate conversion for jitter reduction to the engineers. Accept its efficacy on the basis of simple audition evidence.

The logical upshot is that upgrading your current DAC to one with shinier specs only replaces one half with another half. You end up with a half regardless. Consider to first add a second half to arrive at a whole of DDC+DAC. With JAVS, the building block approach continues with the Clean Power unit. It improves one or two stock wall-wart power adapters. That scheme divides acquisition of the end-game solution over multiple smaller expenditures. It creates a friendlier route to the peak. As such it's another lovely surprise from the Land of the Morning Calm. If I started from scratch, my order for today's order would be JAVS DAC ⇒ Clean Power ⇒ DDC. That maps the sequence of importance. Without DAC I'd have no sound. And DAC+PSU weigh in heavier than adding the DDC. So if you buy in stages and don't yet own a separate DAC, those are the three steps. If you already have a DAC, it's DDC then Clean Power. Either way is a winning strategy.

Delivery: By FedEx direct from Korea with proper tracking #.
Build quality: Excellent.
Communications: Somewhat delayed with PR, excessively delayed with tech support.
Final comments: As new house brand of an apparently very experienced Korean import house which has embarked on a first export endeavor of direct sales, the company must hire the right sales and tech personnel to give their effort a real future. For JAVS, they no longer have dealers to handle those aspects. Now they are the global dealer. After-sales service is on them. This goes beyond great product. It must include prompt knowledgeable English responsiveness especially for impersonal eBay transactions. At review time, JAVS still had to improve their customer service. They might want to model themselves after Singapore's Vinshine Audio. They're a brilliant example for how to properly do Asia-based global sales of Asian hifi products whilst building a sterling reputation for their brands. 

PS: JAVS recently launched their new X5-DAC and X5-DDC which are "easily accessible to beginners and have already received good reviews from Korean audiophiles. Later this year or early next year, we'll launch our flagship model X9-DAC. When the time comes, we'll ask for another review."