@sls883
I was convinced that the Wiim Ultra / Gustard U18 combo performs quite well. Along with the Harmony Micro DAC and upgraded cabling, the system's sound can be described in three words: effortless, transparent, and depth-dealing. I like it very much and I believe it actually outperforms many higher end streamers.
One thing I’d like to check with you—and I hope you can confirm—is this: remember I mentioned the 'static' noise that occurred when the U18 was initially connected to my system? I finally figured out that it’s caused by the I²S channel not receiving a signal while idling. As soon as music starts playing and a signal is present, the noise disappears and the background stays quiet and dark until the unit is powered off and on again. I was advised not to worry about it, but I’d appreciate it if you could confirm whether your U18 ever behaves this way. Please let me know. I may need to swap it out with a brand new, trouble free one.
|
@sls883 Could be, but it could also be defective, since I had no issue with the other DDC.
|
@mattw73 I was using a Ugreen before the LanShack. Hopefully you will perceive the improvement I did.
This time, I’m not sure if I hear a discernible difference. In any case, both are better than the unshielded Cat 5e. The cable is beefy and well-constructed—just a bit stiff due to the solid conductors. Nevertheless, I will possibly ’downgrade’ to Cat 6A, which uses a maximum bandwidth frequency of 500 MHz, instead of 2000 MHz on cat 8, as the latter is more prone to EMI/RFI if not properly grounded on one end. LanShack offers cables with similar specifications.
|
@mattw73 Some one confirms that frequency is determined by data speed and I think Cat 8 cable is not noisier (than cat 6) that produces more EMI/RFI. There is alot misinfor. out there.
|
@mattw73 I think you won’t be disappointed, but your expectations might be different. I came from a flat SS, uninvolving DAC, whereas you had the Pontus 15th. The DH Labs HDMI cable and U18 DDC also make a difference to my system, but you already had quality cabling in place. I’m just grateful I took your advice to be patient—the payoff has been great.
|
@mattw73 I don’t know about Denafrips’ customer service after they shifted their dealership from VinShine, as I don’t own any of their products. But with Laiv, I’ve had numerous correspondences—technical questions and product inquiries—and I always receive first-hand responses from either Weng or Soon within 24 working hours (there is 12 hrs time diff.). Great service, bar none.
@sls883 You’re right about the I²S compatibility. I moved the U18 to pair with the Topping D90III Discrete via I²S, and there’s no static noise—so it seems there’s no issue with the used U18 I got. Now, my second rig sounds noticeably better, again, with the Wiim Ultra + U18 combo.
I recall you mentioned trying to get a Wiim Ultra for your son. Is it still around? If so, I’m curious whether you could conduct a no-confirmation-bias comparison between that combo and the Innuos Zenith Mk III (if that’s the one you have), to see how closely the combo performs against the Zenith. Is it doable? Thx.
|
@mattw73 Is your micro dac fully broken in yet? It should be about time, right. What is you verdict?
I finally purchased the Rivo plue. Hans and many others were not exaggerating, it is on another league from those entry levels and on par with if not exceeding higher end such as Innuos zen / zenith mk iii. But the Volumio app is the limiting factor. Fortunately, Qobuz Connect works well with it.
|
@sls883 No worry. I need to part with the Ultra now, as it’s going to my son tomorrow. I’ve been holding on to it at home, but he finally bought a turntable. I really enjoyed having fun with it over the past few months. Thanks.
|
@sls883 Same here, although it already has pretty low jitter and electrical noise at digital out — one of the best. I was more interested in either the U18 or the Micro DDC, since both support a 10 MHz clock, but the U18 offers much better value and it pairs so well with Ultra.
|
Yes, @soix, the U18 has galvanic isolation on its USB input, and so does the Micro DAC. As I mentioned earlier, the Micro DAC also allows the user to select either the I²S or the local clock, and I slightly prefer using the local clock.
The reason I'm asking now is because the return deadline for the U18 will have passed by the time the Rivo+ arrives.
Anyway, thank you for your response.
|
|
The harmony (micro) Dac is the only Dac I know so far that allows one to choose which clock to go with, I2s vs local (dac) clock. I try both and it seems local clock option yield slight better SQ but I won’t swear to it. Both units (U18 & micro Dac) might have similar grade of clock. I use Ifi Ipower X for the micro Dac and I use 0.5m DHL hdmi 2.1 cable as shown earlier.
With that said, @sns, what you have said below confuses me a bit and please provide some clarification.
By the way, I have Harmony with Denafrips Gaia DDC, sync’d to Gaia via Tubulus Ximius I2S cable.
What clock option you have chosen in Harmony Dac to sync., local (dac) or i2s clock?
This superior to optimized usb vis Sonore OpticalRendu via Audioquest Diamond usb.
This makes sense. The U18/micro DAC via I2s also outperforms the usb (galvanized isolated) input on micro Dac BUT that is because of the weaker source (Wiim Ultra; but still very good when combined with DDC). That is why I am thinking about the upgrade.
|
@audiotroy I think Passion for Sound addresses your question. The i2s sounds comparably, if not better, to usb which is perceived better than AES. Did the homework. But nobody as far as I know does the comparison with and without DDC. Anyone?
https://www.youtube.com/watch?v=D-fEVEdFBnE&t=317s
|
It is good idea to try a good ethernet cable. Thx. Do I also need a good switch box and / or ethernet-optical-ethernet converter there, @audphile1, you think?
|
I’m fine with returning the U18, but I’m fully satisfied with the Harmony Micro DAC and the Rivo Plus/LPS I’m considering. If I ever need a DDC again, I’ll just get a better unit like the SU-6 or the Micro DDC. I’m not sure the folks making that statement have ever actually auditioned these units. I know exactly where the point of diminishing returns is for my system.
|
By the way both DDC and dac use I2S clock, I2S is native pathway in every dac...
No. Don’t assume that. Go back to read your Harmony manual again regarding I2s Clock (Sec. 4.2). It clearly says "This feature enables you to select between the local DAC clock or the I2S clock when utilizing the I2S input." The ’local DAC clock’ option is manifest by itself. If you opt for ’I2S clock’, the DAC will be slaved to DDC’s clock and use the I2S clock unless the I2S clock becomes unstable or incompatible.
This is an unique feature offered by Harmony DAC and µDAC.
|
Keep it simple! I like that answer as long as it is effective. Any suggestion? DH Labs or other vendors that won't break my bank?
|
@sns I am not trying to be argumentative but I respectfully disagree with the generalization you have made regarding:
I2S is the native digital pathway in every dac, this is the DEFAULT clock used regardless of input chosen.
"local clock is in FACT a I2S clock", "just a matter of semantics"
That directly conflicts with the statement in the manual: 'When users switch to other digital inputs, the DAC seamlessly transitions back to using the local clock.' When other inputs are selected, there is no such thing as an 'I²S clock' in that timing information is not pipelined separately from the signal data. Please be precise with the terminology. You may want to double-check with Harmony.
|
@mattw73 Thank you for the recommendation. I like that the cable is affordable, and Cat 6a is more than sufficient for audio applications. I’ll gladly take a $15 cable as long as it works. For the same length, a DH Labs Ethernet cable would cost ten times more (around $300). I’ll definitely give it a try.
|
@moonwatcher You are welcome. It is interesting that you are curious about the Rivo+ jitter performance. There is no measurement yet since it is just released but I found the measurement for Motivo, which is basically Rivio+ plus the DAC and headphone amp. Their streaming circuit and performance is neck to neck according to iiwi but the Rivo+ has a slight edge. See below.
The average (Lt / Rt channel combined) RMS (or so-called 1-sigma) jitter is around 8.2ps (I am not sure which output this measurement is taken from though). See yellow highlighted. Quite impressive.

|
@moonwatcher The 38fs is the jitter rms level in the femto CO (crystal oscillator). The jitter level at outputs can not be that low. Here are some measurements taken from coaxial output of various DDCs by Goldensound for their RMS electrical noise and jitter noise at 48khz.
Jitter(rms) Electrical(rms) Jitter(peak) Electrical(peak)
Holo Red 73ps 2.97mV 213ps 12.9mV
Singxer SU-6 75ps 3.3mV 225ps 13.7mV
Singxer SU-2 KTE 85ps 3.2mV 247ps 13mV
Gustard U18 453ps 5.2mV 1133ps 22mV
You could see U18 jitter and electrical noise performance is lagging. That is why I mentioned I could pick up better DDC like SU-6 or micro DDC later on if needed.
|
|
Once again, if the user opts for the "I2S clock," the DAC or micro DAC will be slaved to the DDC’s clock and will use the I2S clock unless it becomes unstable or incompatible. This is a unique design feature of the Harmony. Still not convinced? Take a look at Harmony’s email response:
When you select “I2S Clock” and it is stable and compatible, the µDAC will indeed lock to and use the incoming I2S clock signal instead of its internal local DAC clock.
In this case, the local DAC clock is effectively bypassed, meaning it is not used during playback. The µDAC will rely fully on the external I2S clock.
It is amazing that some AGs here presume they know everything...
|
@sns I was simply helping to clarify the confusion @audphile1 has with the confirmation from the manufacturer. All right? Cool.
|
@audphile1 Thanks for suggesting I change out my Ethernet cable — it made a significant improvement.
@mattw73 While waiting for the LanShack cable (S/FTP) to arrive, I also grabbed a UGreen Cat 8 (F/FTP) cable from Amazon for just six bucks. Upgrading my existing Cat 5e (U/UTP) to UGreen Cat 8 resulted in a significant improvement in sound clarity and a darker background. It also helped eliminate some digital glare. I believe this is largely due to the double shielding feature of Cat 8. The degree of improvement is comparable to what I experienced with HDMI cable upgrade from AG to DH Labs.
The UGreen cable is made of 26 AWG stranded copper, while the LanShack uses 23 AWG solid copper, which I hope will yield additional sonic benefits. I believe in larger conductor and solid copper over stranded. Thank you for the recommendation.
|
@sls883 I like the WiiM Ultra + U18 combo more and more each time I switch from going USB straight into the microDAC. The soundstage, clarity, reverb, and other aspects are all improved. Coincidentally, another listening section tonight has made me rethink the whole idea of replacing this combo of wonder with a supposedly better streamer.
Feeding an external 10MHz clock to synchronize the streamer/DDC and DAC is still an exciting and promising concept that's on my mind. Whether it would actually outperform—or even match—the results of a higher-end streamer or vice versa remains uncertain. I need to sleep on it. I still have some time to think this through.
|
@mattw73 Same here. I had the UGreen USB-A to Lightning dongle for my EarPods after comparing 2–3 products side by side. That’s why I picked one up this time without hesitation, even though other brands have gold-plated RJ45 connectors—which LanShack doesn’t have either. I hope I ordered the right one. Is this it?

|
@mattw73 My uDac suddenly opened up and delivered all the good stuff at around the 250-hour mark—this was a few days after I connected the U18 to the Ultra and swapped the USB/HDMI cables for a DH Labs Mirage and HDMI 2.1. Its ultimate performance is also due in part to those upgrades. If you’re unsure where the leaner bass is coming from, just swap the uDac with the Pontus while keeping everything else the same—you’ll know right away. But I understand you probably want to make that comparison when uDac is fully burned in.
As for the Volumio app, it’s disappointing compared to others. Qobuz Connect or UPnP apps such as mConnect are good alternatives. In particular, QC works well with the Rivo Plus—it’s never had dropouts and holds up better than QC on the Wiim. However, Volumio does sound noticeably better than either QC or mConnect. That’s why I tolerate its bugs and still use it for playback.
I just got the LHY LPS yesterday, and it further darkens the background. At lower listening levels, the articulation of both high and low notes has taken a step up. All of its digital outputs—SPDIF (AES & coax) and I²S—sound similar to my ears at this moment.
I don’t have a higher-end preamp yet. When I used the Saga2 with the uDac, I found the sound slightly colored and somewhat restrained—not as transparent as running without it. So, I took it out of the chain and now use the Wiim’s 32-bit processor with its harmless ’relayGain’ for volume control. With that technology, I can no longer criticize digital attenuation in the system, which gives no hint of signal loss even at low volume.
Lastly, It’s my expectation that the uDac will perform well—up to a certain percentage of the Pontus 15th. But please tell me, once it’s fully broken in, how it compares to the Pontus in terms of imaging and soundstage dimensions (width, height, and depth), assuming everything else is controlled.
|