[Zarah]

I have old original Schiit Gungnir Multibit (Gumby OG). Performance over Gen2 USB is probably suboptimal, like the Bifrost issues @sajunky mentions for the USB.

Obviously I'm considering the Douk U2 Pro. But now there is the SMSL PO100 Pro which came out since then. It looks nicer and from a better known company.

@sajunky or anyone else, do you have a recommendation? I'm not sure if Coaxial into Gumby uses the VCXO clock regenerator or uses the source clock. I'm not sure if the VCXO clock on there is better than one of the clocks in these other devices.

Has anyone compared the SMSL and Douk side by side, or some other product I don't know?

Also, how would Gustard U16 or Denafrips Iris compare to these?

Thank you for advice! After purchasing one of these I'll give a report on the effect.

 

[sajunky]

I have old original Schiit Gungnir Multibit (Gumby OG). Performance over Gen2 USB is probably suboptimal, like the Bifrost issues @sajunky mentions for the USB.

Obviously I'm considering the Douk U2 Pro. But now there is the SMSL PO100 Pro which came out since then. It looks nicer and from a better known company.

@sajunky or anyone else, do you have a recommendation? I'm not sure if Coaxial into Gumby uses the VCXO clock regenerator or uses the source clock. I'm not sure if the VCXO clock on there is better than one of the clocks in these other devices.

Has anyone compared the SMSL and Douk side by side, or some other product I don't know?

Also, how would Gustard U16 or Denafrips Iris compare to these?

Thank you for advice! After purchasing one of these I'll give a report on the effect.

For me SMSL have no use, as it can't work as a ground loops redirector, it doesn't have connector for the external power supply. It is a main purpose of a DDC, conversion to a different digital format is secondary. A lack of the external power supply can also affect playback from mobile phones. Many phones cannot be loaded with 200mA, it will generate dropouts. Attaching external power supply to my U2 Pro cure this problem in every case.

There is also a question whether clocks can be upgraded on this device. Photos of the PO100 pcb show only one oscilator, while U2 (and a Pro) has three. The clock frequencies for audio are synthesised from a single oscilator. In this hardware it is a cost saving option, not for quality. It brings a suspicion that the same is in a pro version. Unfortunately it cannot be verified as I couldn't find photos what is inside.

It also cannot be verified whether there is a transformer for the coax output or direct coupling like in the PO100. It is why I cannot recommend SMSL.

I didn't see Gumby inside, can't say it is VCXO or a digital PLL, but S/PDIF receiver has to recover a clock from the data stream, clock is not given directly. In any case quality of a source clock matters. Hope it helps.

 

[Winter Sky]

leaf audio option 957,575 on aliexpress, is there a chance that 957,575 is fake?

 

[russwishtart]

Has anyone compared the SMSL and Douk side by side, or some other product I don't know?

I own both the Douk U2 Pro and the SMSL PO100.

I tried both with my SMS DO200 DAC. I tested audio from my Mac mini going into both DCC’s via USB.

For outputs, I tried both coax (RCA) and I2S (via HDMI) from both DCC’s. I did not try the optical output on either.

I could not hear any audio differences between the U2 and the PO100.

 

[fettspeck]

leaf audio option 957,575 on aliexpress, is there a chance that 957,575 is fake?

Can you send a link to the offer?

 

[Winter Sky]

Can you send a link to the offer?

https://redirect.viglink.com/?forma...//m.aliexpress.com/item/1005002207068268.html

 

[sajunky]

WARNING!

 

[Winter Sky]

https://th.aliexpress.com/item/1005002207068268.html?gatewayAdapt=glo2tha

 

[sajunky]

https://th.aliexpress.com/item/1005002207068268.html?gatewayAdapt=glo2tha

Markings look added in a photo editor. It makes sense, considered original cans are engraved, frequently not seen clearly on the photo.

A photo of TCXO part is actually 12MHz oscilator, it confirms that nobody took care to make it look authentic.

If you trust a seller, the best option is TCXO version, you may even get a quality stuff, as such parts are recycled from electronic waste.

If you want Crysteks, the cost effective option is to order a standard version and then DIY replace oscilators. Buy chips from Mouser or Digikey, to make sure there are authentic. Links are posted earlier in this thread.

 

[sajunky]

Not really a poorman DDC, but a real one (almost)(*) with a Morion 10MHz clock! I am sure, a recycled part. Price? Surpise!

U19 USB Digital Interface Thermostatic Crystal Oscillator OCXO Italy USB DOP128

Someone have already ordered it, follow posts from @FredA

(*) if it turns out it has bi-directional USB isolator, it is a real DDC in a mini form, see below.

 

[Guipnox]

Not really a poorman DDC, but a real one (almost)(*) with a Morion 10MHz clock! I am sure, a recycled part. Price? Surpise!

U19 USB Digital Interface Thermostatic Crystal Oscillator OCXO Italy USB DOP128

Someone have already ordered it, follow posts from @FredA

(*) if it turns out it has bi-directional USB isolator, it is a real DDC in a mini form, see below.

I was about to buy that one yesterday because I need AES/EBU.
It's good to know that it's a real DDC. Thanks!
Oh my bad. I read your statement wrongly. I hope someone confirms that it's a real DDC.

I'm going to plug it into a Violectric DAC V800 -> Adcom GFA-5400 -> Adcom GFS-6 speaker selector -> Hifiman HE6se / Revel Concerta 2 M16.
Cables will be budget, but good quality (compatible to my gear).

This setup I hope is going to be "good enough" for a while! But we all know how this hobby works
I'll use it for electronic music production and recreational listening

 

[sajunky]

It's good to know that it's a real DDC. Thanks!
Oh my bad. I read your statement wrongly. I hope someone confirms that it's a real DDC.

Yes, I am not 100% sure, but isolator chips have a characteristic shape (a wide legs layout as seen on the photo in circle) and a lack of oscilators in the Amanero receiver section indicate that Amanero is fed back by the oscilator located on the the clean side. It means full asynchronous delivery of data, no added jitter. It is how isolation is done in DI-20 and Audio GD DACs (R-8 and above). To add to this a quality of a clock, torroidal transformer, separate driver chips for S/PDIF and a pair of transformers, I suspect, this little DDC will beat many other in the $500 price range.

 

[Guipnox]

Unfortunately:

Still tempted to buy it because I don't think a better DDC with AES/EBU can be found close to this price.

 

[rene555]

@Winter Sky

I just received Douk Audio U2 Pro with Crystek CCHD-957 oscillators, which I ordered from the same link from Ali that you provided here (seller - Huo Niu Store). The markings on the oscillators are engraved, as sajunky pointed out here. This, of course, is not a 100% guarantee of the authenticity of the oscillators, but it is what it is.
The soldering quality is good, only connectors, oscillators, LEDs and electrolytic capacitors were soldered by hand. I used alcohol to remove any remaining flux in these points in case it is chemically aggressive.
I can't say anything about the sound yet. I just checked the functionality of the device and connected it to 5V to burn it in for three weeks.
In general, I'm not sure that I need this device. I am quite satisfied with the current sound quality from a PC via USB. But, as they say, curiosity killed the cat.) Let's see.

 

[sajunky]

Unfortunately:


Still tempted to buy it because I don't think a better DDC with AES/EBU can be found close to this price.

Thanks. Is this coming from the official source?

There are actually two chips that could be identified as an isolator. On the first one Google translation is not giving clear answer. The "high performance clock processing" is not helping understanding. I can bet that a main clock synthesiser is located on the S/PDIF chip. A second one (circled) seems linked to the I2S output.