Douk Audio U2Pro Digital Interface Upgrade is Being Planned and Waiting for Your Advice!

[Perpetual Novice]

Hello,

Regarding the U2pro crystal oscillator replacement issue, we have verified it, and the following is the updated information:
To replace the U2 Pro's oscillator, it needs to meet these specs:
24.000MHz/1.8-3.3V (active oscillator)
Can be SMD or through-hole (DIP)
SMD size: 5032
DIP spec: DIP14
Other than meeting those specs and size,the smaller the frequency tolerance (+ppm), the better. Choosing a high-precision TCXO would give a more noticeable improvement.
*We also tested fixed 3.3V,it can work normally as well. But we cannot guarantee that all 3.3-5V will work. But no worries, unmatched oscillator won't cause damage to the U2PRO, but only not work.

Thanks for all your support to our U2pro! To thank everyone for the enthusiastic discussion, we have arranged special Amazon discounts for interested members. If you'd like to make a purchase, please contact me and I will send you the coupon code.

Would this apply to the Femto Oscillator as well? Many thanks!

 

[A Very Private Zootopia]

I’ve been testing the U2 Pro myself, so I thought I’d share where I currently stand and leave a link for anyone who might find the details useful.

In my case, the U2 Pro is used mainly as a USB interface / format converter rather than as a “reclocker”. The source is a laptop that isn’t particularly clean or stable under load, with relatively long USB cable runs. I’ve compared direct USB to DAC(Topping D90III Discrete) versus chains involving a USB isolator (Topping HS02) and the U2 Pro feeding the DAC via coax or I2S.

With a clean and modern USB source, direct USB into a good DAC still makes the most sense. However, with less ideal sources or longer cables, adding isolation and the U2 Pro does help with stability and overall consistency. I would not describe it as a dramatic transformation, but rather as removing small irritations that add up in real-world setups.

I also spent some time looking into the clock discussion. As already mentioned earlier in the thread, the 24 MHz oscillator in the U2 Pro is part of the USB/XMOS side, not an audio master clock. Douk Audio has clarified that compatible replacements need to be 24 MHz active oscillators in the 1.8–3.3 V range (SMD 5032 or DIP-14). From what I’ve seen so far, there is no solid measurement evidence that swapping this oscillator produces a meaningful improvement when feeding modern DACs with proper internal clocking. At best, it should be treated as a DIY experiment rather than a guaranteed upgrade.

Overall, I see the U2 Pro as an externalized XMOS interface with some useful options: isolation, format conversion, and flexibility. It can make sense depending on the source and system constraints, but it doesn’t replace a well-designed USB input in a modern DAC.

I’ve written a more detailed breakdown of my setup, comparisons, and clock research on my blog here, in case anyone is interested:

차이파이 DDC 맛집 Douk Audio U2 Pro(Ver.2)를 철저히 파헤쳐 보자!

0. 들어가며최근 Wiim Pro 2대를 정리하고 품질 좋은 네트워크 스트리머를 찾아보는 중이었다. 그런데 가격이 비싼 스트리머 대부분이 DAC 기능의 비중이 많은 것을 보고, 독립된 DAC를 사용하는 필자로서 중복 투자가 될 것 같다는 생각이 들어 꺼려졌다. 그렇다면 원점으로 돌아와서 네트워크 스트리머의 품질은 어디에서 좌우될까?충실한 전원부, 고품질 클럭, OS, 스트리밍 앱 환경 정도일 텐데 막상 일부 제품 스펙을 보면 과도하게 DAC 성능을 강조하거나, 전원부가 SMPS 어댑터인 경우가 많았는데 이런 것들은 필자가...

grancartzoo.tistory.com

 

[Roland68]

I’ve been testing the U2 Pro myself, so I thought I’d share where I currently stand and leave a link for anyone who might find the details useful.

In my case, the U2 Pro is used mainly as a USB interface / format converter rather than as a “reclocker”. The source is a laptop that isn’t particularly clean or stable under load, with relatively long USB cable runs. I’ve compared direct USB to DAC versus chains involving a USB isolator (HS02) and the U2 Pro feeding the DAC via coax or I2S.

With a clean and modern USB source, direct USB into a good DAC still makes the most sense. However, with less ideal sources or longer cables, adding isolation and the U2 Pro does help with stability and overall consistency. I would not describe it as a dramatic transformation, but rather as removing small irritations that add up in real-world setups.

I also spent some time looking into the clock discussion. As already mentioned earlier in the thread, the 24 MHz oscillator in the U2 Pro is part of the USB/XMOS side, not an audio master clock. Douk Audio has clarified that compatible replacements need to be 24 MHz active oscillators in the 1.8–3.3 V range (SMD 5032 or DIP-14). From what I’ve seen so far, there is no solid measurement evidence that swapping this oscillator produces a meaningful improvement when feeding modern DACs with proper internal clocking. At best, it should be treated as a DIY experiment rather than a guaranteed upgrade.

Overall, I see the U2 Pro as an externalized XMOS interface with some useful options: isolation, format conversion, and flexibility. It can make sense depending on the source and system constraints, but it doesn’t replace a well-designed USB input in a modern DAC.

I’ve written a more detailed breakdown of my setup, comparisons, and clock research on my blog here, in case anyone is interested:

차이파이 DDC 맛집 Douk Audio U2 Pro(Ver.2)를 철저히 파헤쳐 보자!

0. 들어가며최근 Wiim Pro 2대를 정리하고 품질 좋은 네트워크 스트리머를 찾아보는 중이었다. 그런데 가격이 비싼 스트리머 대부분이 DAC 기능의 비중이 많은 것을 보고, 독립된 DAC를 사용하는 필자로서 중복 투자가 될 것 같다는 생각이 들어 꺼려졌다. 그렇다면 원점으로 돌아와서 네트워크 스트리머의 품질은 어디에서 좌우될까?충실한 전원부, 고품질 클럭, OS, 스트리밍 앱 환경 정도일 텐데 막상 일부 제품 스펙을 보면 과도하게 DAC 성능을 강조하거나, 전원부가 SMPS 어댑터인 경우가 많았는데 이런 것들은 필자가...

grancartzoo.tistory.com

Very well put and to the point, and that completely matches my experience with various DDCs and quartz crystals in recent years.

 

[Alan O]

Hi folks, I was researching the Douk U2 Pro XMOS XU316, and I found this very helpful thread - thank you all for that. I bought one and I've had it a few days, so I thought I'd register and share my experience.

My source is an old Mac Mini (not sure what age, but old), via USB into an Audiolab M-DAC (original, not Plus). USB is all I can use, as the optical output from the Mac has never worked since I got it (bought used). The sound has always seemed a bit harsh and edgy, and fatiguing to listen to for any length of time. But the money hasn't been around for considering DAC (or other) upgrades, and I'd assumed the Mac Mini was probably a big part of the problem.

Anyway, £50 for a Douk U2 Pro is the kind of money I could risk, and I now have the Douk driving the DAC via coax - I2S would have been nice, but the M-DAC doesn't have an I2S input.

The result is a significant improvement. Mellower, not harsh and edgy, with improved resolution and tighter bass. I'm hearing details in some favourite recordings I've never heard before, and clearer intrument timbre differences. I've had it playing almost all day since I got it, with none of the old fatigue.

Overall, I see the U2 Pro as an externalized XMOS interface with some useful options: isolation, format conversion, and flexibility. It can make sense depending on the source and system constraints, but it doesn’t replace a well-designed USB input in a modern DAC.

That's pretty much where my thoughts are too. I think the M-DAC uses a fairly old TI USB controller, and is trying to deal with what I expect is quite a nasty USB interface from the Mac. I reckon the Douk with its XU316 is probably just much better at handling it.

Also, I think coax into the DAC sounds a bit better than optical. I don't know why that might be - and I'm really not sure of it anyway as I haven't done any proper A/B comparisons, but I thought I'd throw it in.

Thanks again for an informative thread, and I hope this is of some interest.
Alan

 

[Devast8nDiscoDave]

I got this device and I've an oscillator on the way I want to replace. I know it's noon question but so I have to remove the old oscillator before installing the new one? I just want to make sure before I go ahead. I assume that I do but I want to make sure.

 

[A Very Private Zootopia]

이 기기를 구입했는데, 교체할 발진기를 주문해서 배송 중입니다. 당연한 질문인 건 알지만, 새 발진기를 설치하기 전에 기존 발진기를 제거해야 하나요? 작업하기 전에 확실히 알고 싶어서요. 당연히 그래야 할 것 같긴 한데, 그래도 확인하고 싶습니다.

Of course, the original oscillator needs to be removed.
May I ask which oscillator you purchased?

 

[Devast8nDiscoDave]

Of course, the original oscillator needs to be removed.
May I ask which oscillator you purchased?

I went the same one in this thread, txco.

 

[Alan O]

The oscillator replacement seems intriguing to me too. I'm not convinced it would make any audible difference (though I don't know enough to claim it won't either). But I do electronics and if it's cheap enough to try... at least finding I'm not missing out on anything would be satisfying in its own way.

It wouldn't be for a while though, the way it is should keep me going for some time yet.

 

[A Very Private Zootopia]

The oscillator replacement seems intriguing to me too. I'm not convinced it would make any audible difference (though I don't know enough to claim it won't either). But I do electronics and if it's cheap enough to try... at least finding I'm not missing out on anything would be satisfying in its own way.

It wouldn't be for a while though, the way it is should keep me going for some time yet.

I bought the U2 Pro because Douk Audio marketed it as having a “replaceable/upgradeable oscillator” design.
However, I still haven’t been able to find a truly trustworthy replacement oscillator in either SMD 5032 or DIP-14. So far, every attempt has failed.
And honestly, I’m not willing to gamble on random, no-name oscillators from AliExpress. When it comes to a clock, reliability comes first.

I’d really appreciate it if someone could point me toward a reliable oscillator from a reputable manufacturer, like SiTime, Abracon, SJT, Epson or ETC.

 

[Alan O]

And honestly, I’m not willing to gamble on random, no-name oscillators from AliExpress

Agree 100%

 

[A Very Private Zootopia]

I’d really appreciate it if someone could point me toward a reliable oscillator from a reputable manufacturer, like SiTime, Abracon, SJT, Epson or ETC.

I’ve found a Crystek CCHD oscillator and plan to try replacing it myself.
The size is a bit awkward, so it requires line extension wiring, which adds some burden, but at this point it seems like the best available option.

 

[Devast8nDiscoDave]

I found this driver that works with Win11 .

SUCA_USB Audio_For Windows

MediaFire is a simple to use free service that lets you put all your photos, documents, music, and video in a single place so you can access them anywhere and share them everywhere.

www.mediafire.com

 

[Perpetual Novice]

I found this driver that works with Win11 .

SUCA_USB Audio_For Windows

MediaFire is a simple to use free service that lets you put all your photos, documents, music, and video in a single place so you can access them anywhere and share them everywhere.

www.mediafire.com

Thanks very much! Your timing on this was perfect! Hope you having an excellent holiday season and have a happy new year!

 

[pat355]

what is the benefit of getting a version with either the TXCO or Femtosecond oscillators in the U2 Pro?

 

[Alan O]

what is the benefit of getting a version with either the TXCO or Femtosecond oscillators in the U2 Pro?

I believe the argument is that a more accurate clock will reduce jitter even more - though whether there is any benefit appears to be highly debatable.

 

[pat355]

I believe the argument is that a more accurate clock will reduce jitter even more - though whether there is any benefit appears to be highly debatable.

thank you!

 

[somebodyelse]

I believe the argument is that a more accurate clock will reduce jitter even more - though whether there is any benefit appears to be highly debatable.

It's rather like the opamp rolling options - they're happy to make an advertising point out of it, but fail to provide any measurements to demonstrate it improving performance. That makes me suspect they either haven't done the measurements, or the measurements don't show what they'd like them to.

 

[Alan O]

It's rather like the opamp rolling options...

Slight tangent, but I always wonder about people who buy op-amp devices with the plan to replace the IC op-amps with expensive discrete versions... why not just buy a discrete component device in the first place?

 

[A Very Private Zootopia]

It's rather like the opamp rolling options - they're happy to make an advertising point out of it, but fail to provide any measurements to demonstrate it improving performance. That makes me suspect they either haven't done the measurements, or the measurements don't show what they'd like them to.

The DDC and oscillator clock upgrade topic is not in the same category as the op-amp rolling debate. With oscillators, the target variables are clearly defined -things like phase noise, jitter, ppm accuracy, and temperature stability- and the specifications and measured results are data that can be used directly for design validation and quality comparison.

By contrast, changes caused by swapping op-amps can also be measured, but they are difficult to summarize cleanly into a single metric like SINAD. On top of that, the interpretation becomes more complicated because results can vary depending on the measurement setup and conditions, so it’s not something that’s often handled well in the typical way communities discuss measurements.

 

[pat355]

if I connect an NVDIA TV Shield Pro by USB to the Douk Audio U2 Pro, should I use the UAC 1.0 or UAC 2.0 setting?