[sajunky]

Standard version is 2017 design with I2S header, but no HDMI (LVDS). At least according to the photo. An upgraded versions are with HDMI connector and PCB looks identical to U2Pro.

 

[pokrog]

I came across this today - Leaf Audio CMD-17 - w/ the options of upgraded clocks - valid alternative to the Douk since the upgraded versions are sold out?

Edit - cheaper link:
https://www.aliexpress.com/item/1005003276907662.html

It's the same thing. I've opened the U2 pro and CMD-17 femtosecond crystek one up and they're identical apart from the clocks.

 

[Alpacasmokes]

Here it is. Upgrading process require elementary knowlegde how to handle electronic components and ESD protection. First you need to measure a voltage in the place indicated by the arrow (photo). Against ground? Oh, forgotten... It is on the opposite corner of the oscilator. If it is 3.3V, you can follow ordering these oscilators.

You need a pair of 22.5792MHz and 24.576MHz oscilators. A board layout is universal, it will accept SMD packages 7050, 1409, and a through the hole DIP14. On the board there are soldered 7050 (7x5mm) SCT devices. Do not follow Crystekmania. I do list these devices first, as I ordered it for upgrading Amanero Combo 384 but other brands are reported to sound better. Crystek oscilators are dependent on noise coming from power supply, others are better protected.

The same 7x5mm size Crystek CCHD-575 <$13 each
Currently on stock:
https://www.mouser.com/access/?pn=CCHD-575-25-22.5792
https://www.mouser.com/access/?pn=CCHD-575-25-24.576

Large 9x14mm Crystek CCHD-957 $27 each
https://www.mouser.com/access/?pn=CCHD-957-25-22.5792
https://www.mouser.com/access/?pn=CCHD-957-25-24.576

Accusilicon AS318-B
These oscilators are offered in three packages, even in a miniature 2520 (2.5x2mm). There are used in Audio GD equipment (Crystek CCHD was also on offer, not anymore), Singxer, Denafrips and other. If you can find a reputable dealer, it is a good choice.

NZ2520SB/SD available for a while and is highly regarded. The latest model is NZ2520SDA offering more than 10dB better noise level at @10hz than Crystek. Only available in a miniature package 2.5x2mm. Even if a board do not have extended pads, it is still possible to solder it in. Typically sold in bulk quantities (thousands pieces), the only retail link I know is this $8 each:
https://www.diyinhk.com/shop/audio-kits/128-ndk-nz2520sda-33v-49152mhz-451584mhz-24576mhz-225792mhz-ultra-low-phase-noise-oscillator.html

When I will modify my board, I will also look at power supply and how it improve it further. Oscilators is only the beginning.

Soldering:
You need a hot-air rework station or two ESD-safe soldering irons with medium-to-small soldering tips. And some basic soldering skills. Without hot air station you need a helper. Removing the existing oscilator require heating up simultaneously all four soldering points. One iron will operate on one side, alternating heat between two joints. First apply some flux to the joints, it will help to break corrosion layer. Do not use tip presure. It should take no more than 7 second to chip come out. If longer, stop and let it cool down, then adjust a temperature. Clean contact area and apply new flux. Place an new chip (observing pin #1 position), do not push down, let it position itself when heating up. Apply the same heating procedure. While it is possible to use one soldering iron, it is better to heat it up on all sides, it will reduce exposure to the mechanical stress. Or give this job to a local cellphone repair shop.

Hi Sajunky,

Hoping to hit you up with some noob questions. BTW did you end up upgrading you oscillators. Pics would be great if you have some?

Can't seem to find any of the accusilicon with the right frequency.

Also with the NZ2520s how easy is it to solder the miniature package?

Cheers

 

[sajunky]

I upgraded Amanero board with Crystek, see link. I did not upgrade U2Pro, as it arrived defective, so I don't know whether U2Pro has pad extensions for smaller NDK parts. I never soldered NDK's, 'easy' is a relative word. If you never tried soldering yet, better give this job to the workshop.

 

[Alpacasmokes]

I upgraded Amanero board with Crystek, see link. I did not upgrade U2Pro, as it arrived defective, so I don't know whether U2Pro has pad extensions for smaller NDK parts. I never soldered NDK's, 'easy' is a relative word. If you never tried soldering yet, better give this job to the workshop.

Thank you!

 

[ES_EF]

I've tried both the basic U2 Pro and the one with the 957 clocks, both with power coming from the USB and from the DC input

ultimately i went with Ipowerx (5v 3.0A, able to handle 4.0A peaks) feeding the DC input, although i did try a silly level of power supplies

i use it to convert USB C from my Samsung to I2S into the Singxer SDA-6 Pro, sounds excellent, miles better than feeding the tablet straight into the DAC, btw these 4n Silver USB and I2S cables being sold on Aliexpress are pretty darn good for the price

 

[Starfox]

Hello guys. I received today the Dook U2 Pro, basic version. So far it sounds good.

My remarks:
- you do have to select a proper USB port. One was generating lots of pop and crackles. Another USB port in much better, but there might be some more cackles.
- I used the USB cable found in the box. Doesn't seem to bad. Monoprice is out of their audio USB...
- I quickly compared coax vs optical output. No difference to me but I'm pretty bad at hearing differences.
- The coax output is very loose. I cannot insert the cable more than a few milimeters, or so it seems. It's weird, as if the plug was too short. So I use optical.
- I had some trouble installing the drivers. When you just plug the Dook, the PC (win10) recognizes as IDF Speaker I believe. And it sounds nice, clean. Then I installed the driver (thank you to the person who posted the link as I have no CD Rom player and there is no QR code on the manual). You install the driver, and a device is detected but failled to be recognized. This is where I got it wrong, I let windows install a driver, and it picked something and looked like it worked but no, it was more like a half baked attempt. I was about to desinstall and give up, but I reboot the PC, and reinstalled the driver, and it worked, the unrecognized device became an Xmos XS1-U8 DJ (ST) device. And the sound seems bigger with more meat.
- I simply use MusicBee, I don't know much about Wasapi or other, so I don"t know if I missed an installation step.
- seems like Mark Knofler's voice is more in the back in Sultans Of Swing, my fave song. But Hotel California sounds great.

Question :
- if I buy a PSU and plug it, does it automatically disable the USB powering?
- do you confirm that a linear cheap AliExpress PSU would add something?

Overall, a nice upgrade for the cheap or low-budget guys.

FI, my rig is PC win10->cheap USB cable->Dook U2 pro->monoprice optical->Xduoo Xa-10 (with a linear PSU)->nice LSA XLR cable->LSA HP2 cans

 

[sajunky]

@Starfox. Thank you for report. Drivers should be installed with device unplugged. You have managed to do it eventually, but it is better that way.

Yes. When you attach a plug from the external power supply, there is an internal switch in the socket that activate relay. In result USB 5V wire is disconnected then U2Pro reset itself and register to the system again for a self powered operation.

 

[Starfox]

Today I did some A/B testing
A. Optical PC-DAC
B. USB Douk - Coax - DAC (Xduoo XA-10)

Sorry to say, I hear no difference. I think it's all placebo, or maybe my set up is not good enough, or my Xduoo is good enough and doesn't need the Douk...
I'll send it back to Amazon.

 

[sajunky]

Today I did some A/B testing
A. Optical PC-DAC
B. USB Douk - Coax - DAC (Xduoo XA-10)

Sorry to say, I hear no difference.

Difficult to say. What PC DAC do you have? Some cards are good quality. Did you try optical from U2Pro as well?

I think sound is deteriorated on the PC by using system mixer instead of bit-perfect transfers. It needs a dedicated player like Foobar 2000 and a correct settings. Do you use ASIO output in the player? It is the easiest way to get bit-perfect playback. Other than that, source quality of your music is important. Compressed dynamic files of "loudness war" mastering practice do not help, not to mention MP3 compressed music.

 

[Starfox]

I have an Xduoo XA-10 which is both amp and DAC. and cost about $500.
I mostly have MP3 320kps and some FLAC. I stream from regular Spotify. I use musicBee with WASAPI (Shared).
And yes, I tried with optical too.

I will try to set up Foobar as indicated on the Douk manual.

 

[gimmeheadroom]

I have an Xduoo XA-10 which is both amp and DAC. and cost about $500.
I mostly have MP3 320kps and some FLAC. I stream from regular Spotify. I use musicBee with WASAPI (Shared).
And yes, I tried with optical too.

I will try to set up Foobar as indicated on the Douk manual.

There's no point spending money on MP3 and Spotify and expecting it to sound great, it never will.

Musicbee is fine, but you need to use the ASIO drivers or if you insist on WASAPI, then exclusive mode.

 

[Starfox]

I set up Foobar as explained in the manual. I have yet to A/B test.
But there are lots of static and crakles. It ruins everything. It could be my regular USB cable feeding the Douk. I need to experiment more.

edit: crackles with the Douk confirmed.

Thank you guys for your replies.

 

[Telin]

Musicbee is fine, but you need to use the ASIO drivers or if you insist on WASAPI, then exclusive mode.

Why the obsessive focus on ASIO?
There is not a single source that proves that ASIO is better for SQ than WASAPI exclusive.. other then the anecdotal I "hear" a difference and therefor it is true which is completely meaningless.

On the other hand one can read on the ASIO plugin page of Foobar that one should not believe the audiophile myth that ASIO sounds better and only use ASIO when there's no other option. Then there are the several measurements that shows that there is not a meaningful difference between the signal from a source using ASIO or WASAPI.

 

[gimmeheadroom]

Why the obsessive focus on ASIO?

Who says it's obsessive?

There is not a single source that proves that ASIO is better for SQ than WASAPI exclusive.. other then the anecdotal I "hear" a difference and therefor it is true which is completely meaningless.

Nonsense. ASIO was designed by a leading company in pro audio to provide bit-perfect audio for commercial production. All the other choices came from Microslob. The only good reason not to use ASIO is if you have a device that doesn't have ASIO drivers.