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

[Schlippwhip68]

I also find it absolutely ridiculous that a device operating at 5 volts and a maximum power of 2.5 watts could in any way endanger a person's life.
Es gibt zig millionen, oder sogar über eine milliarde geräte auf der Welt die mit USB 2.0 betrieben werden, und das seit 25 jahren, aber von so etwas habe ich noch nie gehört.

Furthermore, it's clearly a DIY project; learn and take responsibility if you're going to do it.
The moment you open a device and modify something, you alone are responsible for it, and no one else.

My apologies, it’s a question rather than a statement, I have amended the post accordingly.

 

[Schlippwhip68]

I also find it absolutely ridiculous that a device operating at 5 volts and a maximum power of 2.5 watts could in any way endanger a person's life.
Es gibt zig millionen, oder sogar über eine milliarde geräte auf der Welt die mit USB 2.0 betrieben werden, und das seit 25 jahren, aber von so etwas habe ich noch nie gehört.

Furthermore, it's clearly a DIY project; learn and take responsibility if you're going to do it.
The moment you open a device and modify something, you alone are responsible for it, and no one else.

Sorry, I don’t agree with this statement, it’s an incredibly dismissive attitude. If someone has recommended an DIY upgrade on their product, it is their responsibility to provide information thereafter as to exactly what the product can be upgraded with to avoid any problems.
If that’s not a law yet then it should be.

The original clock operates at 1.8v and the compatibility of jumping from that rate to 3.3v is a point of question that needs to be clarified primarily by the manufacturer and really should not be a point of contention.
In regards to safety then that is what we here to determine as per reasonable enquiry and again not out of contention.

Please respond with a degree of civility and understanding.

 

[Roland68]

Sorry, I don’t agree with this statement, it’s an incredibly dismissive attitude. If someone has recommended an DIY upgrade on their product, it is their responsibility to provide information thereafter as to exactly what the product can be upgraded with to avoid any problems.
If that’s not a law yet then it should be.

The original clock operates at 1.8v and the compatibility of jumping from that rate to 3.3v is a point of question that needs to be clarified primarily by the manufacturer and really should not be a point of contention.
In regards to safety then that is what we here to determine as per reasonable enquiry and again not out of contention.

Please respond with a degree of civility and understanding.

The manufacturer sets the possibilities and parameters.
You are the one who has to decide whether your own DIY skills are sufficient or not.

DIY requires certain skills, or the ability to acquire them.
At the very latest, if Douk Audio had soldered in a socket for plugging in the device, it would no longer be DIY.

If you open a device and modify something, no manufacturer in the world can be held responsible.
They can neither control your work, nor your capabilities or abilities.
And that's exactly how such cases have been decided legally in recent decades.

I've been doing this kind of thing for as long as I can remember—repairs and modifications—and it never occurred to me that the manufacturer could be liable for any of it.

I also absolutely cannot see how a human life could be endangered by a device powered exclusively via USB 2.0, without an additional power supply option. That's not even possible if you touch something inside an open device while it's operating.

My work involves the manufacturing, development, and operation of high-energy products that use direct current up to the double-digit kV range. I have the appropriate first aid training and am also medically trained to handle such accidents. So, I don't just know the technical side of things.
How should one react when someone spreads such misinformation?

This can lead to endangering life and a problem with the law which in turn makes Douk Audio liable if things go wrong.

 

[somebodyelse]

The argument as I understand it is that on the product page Douk have a graphic using the DIY possibilities as a selling point:

Reserved Large Space for Oscillator DIY
Upgrade Your Clock, Upgrade Your Sound - Customize your sound by soldering a replacement oscillator.

However they don't provide any information about oscillator compatibility other than stating the footprint size. If they're going to use it as a selling point they should have more information, otherwise anyone could claim DIY upgrades are possible because skilled users could desolder and change anything.

 

[Roland68]

The argument as I understand it is that on the product page Douk have a graphic using the DIY possibilities as a selling point:

However they don't provide any information about oscillator compatibility other than stating the footprint size. If they're going to use it as a selling point they should have more information, otherwise anyone could claim DIY upgrades are possible because skilled users could desolder and change anything.

You've described DIY modifications very well, because that's exactly what's been done for decades and is one of many facets of the DIY field.

For most users here, a pluggable socket and suitable adapter boards with soldered-on crystals would of course be simpler, as is done with op-amps, but that's no longer DIY. That's more like plug and play.

There's a large DIY scene in the audio field with many forums and vendors, and crystal modifications have been around for almost 35 years, using both crystals and modules.
If you look closely, there are many small vendors offering crystal modules, as well as installation services.
Similarly, you can find countless modifications of CD players, DACs, DDCs, and many other devices, also involving crystals. There were no specifications, instructions, etc.; these people figured it all out themselves.
That's DIY.

Thanks to Douk Audio, DIYers no longer need to buy DDCs for €/$500, €1000, €1500, or more. They can now experiment with a device for €69, minimizing the risk of failure.
And Douk Audio has even left space and options on the circuit board for DIY projects. That's fantastic!
Now every DIYer can freely choose what they want to install: crystals of any kind, DIP14 femto modules, and all other available crystal modules, including external ones.

And that's DIY too.
It seems to me that some users here are confusing DIY with plug and play.

Perhaps Douk Audio would be kind enough to suggest a few alternative crystals, but that's not their responsibility.
FFor everyone else, Douk Audio offers two devices with pre-installed, higher-quality crystals.

 

[somebodyelse]

I've been doing mods and repairs on pre-existing hardware, and making my own from scratch for decades, so have a pretty good idea what DIY involves. The difference is manufacturers have never advertised the DIY side unless they were selling kits, had socketed components or some other DIY friendly feature beyond normal manufacturing practice. All sorts of manufacturers use alternate pad layouts to accommodate different packages for cost or availability reasons, or even alternate models with different board stuffing, but they don't boast about it in their product descriptions.

For everyone else, Douk Audio offers two devices with pre-installed, higher-quality crystals.

They're planning to - neither are available yet.

 

[Schlippwhip68]

Douk Audio if you are reading this post, which I do hope you are, then can you please clarify whether a 3.3v - 5v TXCO clock can be used where the 1.8v clock has been implemented.

There are many of us whom wish to get on and upgrade the unit but currently, if like me, are held back through lack of information upon your recommendation/suggestion for replacement of the units clock.

As we can all see someone on your review section for this unit on your own website has proceeded with an upgrade using an 3.3v - 5v clock. I personally do not wish to do this without confirmation for you the manufacturer as to whether the voltage rate of the clock can be raised from 1.8v to 3.3-5v without any damage to the surrounding circuitry.

Eagerly waiting your answer.

Steve.

 

[Schlippwhip68]

The manufacturer sets the possibilities and parameters.
You are the one who has to decide whether your own DIY skills are sufficient or not.

DIY requires certain skills, or the ability to acquire them.
At the very latest, if Douk Audio had soldered in a socket for plugging in the device, it would no longer be DIY.

If you open a device and modify something, no manufacturer in the world can be held responsible.
They can neither control your work, nor your capabilities or abilities.
And that's exactly how such cases have been decided legally in recent decades.

I've been doing this kind of thing for as long as I can remember—repairs and modifications—and it never occurred to me that the manufacturer could be liable for any of it.

I also absolutely cannot see how a human life could be endangered by a device powered exclusively via USB 2.0, without an additional power supply option. That's not even possible if you touch something inside an open device while it's operating.

My work involves the manufacturing, development, and operation of high-energy products that use direct current up to the double-digit kV range. I have the appropriate first aid training and am also medically trained to handle such accidents. So, I don't just know the technical side of things.
How should one react when someone spreads such misinformation?

Well maybe you could help clarify wether it would be possible to actually upgrade this unit using an 3.3v-5v clock and remain stable…perhaps!

Regardless to say I have ordered a second unit and an TXCO 24mhz 3.3v-5v clock and will find out.

So, this review and photo remains on Douk Audios website I assume without any correction from Douk Audio towards the review and photo since it has been up that it is a plausible upgrade.

 

[Roland68]

Well maybe you could help clarify wether it would be possible to actually upgrade this unit using an 3.3v-5v clock and remain stable…perhaps!

Regardless to say I have ordered a second unit and an TXCO 24mhz 3.3v-5v clock and will find out.

So, this review and photo remains on Douk Audios website I assume without any correction from Douk Audio towards the review and photo since it has been up that it is a plausible upgrade.View attachment 493909

Could you post the link to the datasheet for the TXCO 24MHz 3.3V-5V clock?
And then please measure the supply voltage to the crystal on the U2 Pro. It should be pad 4 on the SMD version and pin 14 on the DIP version.

 

[Schlippwhip68]

Could you post the link to the datasheet for the TXCO 24MHz 3.3V-5V clock?
And then please measure the supply voltage to the crystal on the U2 Pro. It should be pad 4 on the SMD version and pin 14 on the DIP version.

View attachment 494021

I just found this on AliExpress: ￡21.93 | TCXO DIP-14 24M 24MHZ 24.000MHZ Gold Plated Rectangular Temperature Compensated Crystal Oscillator Golden 3.3V-5V 0.1PPM

https://a.aliexpress.com/_EQlYsac

This is the exact one ordered. I am afraid I do not have any equipment at my disposal for measuring.

 

[Roland68]

I just found this on AliExpress: ￡21.93 | TCXO DIP-14 24M 24MHZ 24.000MHZ Gold Plated Rectangular Temperature Compensated Crystal Oscillator Golden 3.3V-5V 0.1PPM

https://a.aliexpress.com/_EQlYsac

This is the exact one ordered. I am afraid I do not have any equipment at my disposal for measuring.

Without a multimeter, I would advise against attempting such DIY projects.
You should measure various things before starting the modification to have reference points in case of problems.
This also applies to the voltages inside the device and the crystals.
It's quite possible that Douk Audio accidentally provided incorrect information, and that the SMD crystal is supplied with 1.8 volts and the DIP14 socket with 3.3 volts. The voltage regulators are present.
A decent multimeter costs €15-50 and is practically indispensable.

I have a bad feeling about the crystals. No datasheet, as every reputable manufacturer provides. The gold plating is also complete nonsense and does absolutely nothing. I've never seen anything like that from any industrial manufacturer. I suspect they are cheap crystals in a shiny package that don't even come close to meeting the specifications.
Perhaps you know someone who can measure them for you. Alternatively, maybe there's a fab lab/makerspace or university near you.

 

[Schlippwhip68]

Without a multimeter, I would advise against attempting such DIY projects.
You should measure various things before starting the modification to have reference points in case of problems.
This also applies to the voltages inside the device and the crystals.
It's quite possible that Douk Audio accidentally provided incorrect information, and that the SMD crystal is supplied with 1.8 volts and the DIP14 socket with 3.3 volts. The voltage regulators are present.
A decent multimeter costs €15-50 and is practically indispensable.

I have a bad feeling about the crystals. No datasheet, as every reputable manufacturer provides. The gold plating is also complete nonsense and does absolutely nothing. I've never seen anything like that from any industrial manufacturer. I suspect they are cheap crystals in a shiny package that don't even come close to meeting the specifications.
Perhaps you know someone who can measure them for you. Alternatively, maybe there's a fab lab/makerspace or university near you.

I wasn’t convinced with the gold plating either. They do offer a product data sheet upon request of which I have done. If they email the sheet I will post it here for your learned perusal sir!

 

[Douk Audio]

Hey everyone,

Thanks a lot for all your support and the great discussions about the U2pro, sorry for joining in a bit late!

Our engineers recommend using a replacement crystal oscillator with a voltage range of 1.8–3.3V, but please note that the frequency must be fixed at 24MHz.

Also, we reached out to the customer who mentioned on our website that they replaced the oscillator with a 3.3–5V one. He confirmed that the U2pro works perfectly after the swap. However, since he replaced it right after receiving the U2pro, he didn’t compare it with the stock oscillator, so we didn’t get feedback on any sound changes.

I’ve also shared this discussion with our product team. Our engineers have ordered oscillators with different voltage specs today and will run compatibility and performance tests soon. Please stay tuned for updates!

Of course, regarding the temperature-compensated oscillator and femtosecond-grade oscillator versions we’re planning to launch, feel free to share your thoughts here or contact us at [email protected].

Wishing you all the best.

 

[Schlippwhip68]

Hey everyone,

Thanks a lot for all your support and the great discussions about the U2pro, sorry for joining in a bit late!

Our engineers recommend using a replacement crystal oscillator with a voltage range of 1.8–3.3V, but please note that the frequency must be fixed at 24MHz.

Also, we reached out to the customer who mentioned on our website that they replaced the oscillator with a 3.3–5V one. He confirmed that the U2pro works perfectly after the swap. However, since he replaced it right after receiving the U2pro, he didn’t compare it with the stock oscillator, so we didn’t get feedback on any sound changes.

I’ve also shared this discussion with our product team. Our engineers have ordered oscillators with different voltage specs today and will run compatibility and performance tests soon. Please stay tuned for updates!

Of course, regarding the temperature-compensated oscillator and femtosecond-grade oscillator versions we’re planning to launch, feel free to share your thoughts here or contact us at [email protected].

Wishing you all the best.

Thanks.

 

[Roland68]

Hey everyone,

Thanks a lot for all your support and the great discussions about the U2pro, sorry for joining in a bit late!

Our engineers recommend using a replacement crystal oscillator with a voltage range of 1.8–3.3V, but please note that the frequency must be fixed at 24MHz.

Also, we reached out to the customer who mentioned on our website that they replaced the oscillator with a 3.3–5V one. He confirmed that the U2pro works perfectly after the swap. However, since he replaced it right after receiving the U2pro, he didn’t compare it with the stock oscillator, so we didn’t get feedback on any sound changes.

I’ve also shared this discussion with our product team. Our engineers have ordered oscillators with different voltage specs today and will run compatibility and performance tests soon. Please stay tuned for updates!

Of course, regarding the temperature-compensated oscillator and femtosecond-grade oscillator versions we’re planning to launch, feel free to share your thoughts here or contact us at [email protected].

Wishing you all the best.

Thank you for your feedback.

Is the voltage supply (vdd) of the oscillator 1.8 volts for SMD and DIP14, or 1.8 volts for SMD and 3.3 volts for DIP14?

 

[Schlippwhip68]

Thank you for your feedback.

Is the voltage supply (vdd) of the oscillator 1.8 volts for SMD and DIP14, or 1.8 volts for SMD and 3.3 volts for DIP14?

View attachment 494822

Great question Roland68, I have a hunch it maybe so….in regards to any sound difference, after some research, it appears the SMD might be a little noisier and less stable than its TXCO counterpart.

I highly doubt the standard U2 has an higher end SMD so probably any decent TXCO replacement should, theoretically, improve the sound quality with less noise at least.

That being said, the U2 in standard stock form is very good and I am pleased with my purchase.

 

[Perpetual Novice]

Hey everyone,

Thanks a lot for all your support and the great discussions about the U2pro, sorry for joining in a bit late!

Our engineers recommend using a replacement crystal oscillator with a voltage range of 1.8–3.3V, but please note that the frequency must be fixed at 24MHz.

Also, we reached out to the customer who mentioned on our website that they replaced the oscillator with a 3.3–5V one. He confirmed that the U2pro works perfectly after the swap. However, since he replaced it right after receiving the U2pro, he didn’t compare it with the stock oscillator, so we didn’t get feedback on any sound changes.

I’ve also shared this discussion with our product team. Our engineers have ordered oscillators with different voltage specs today and will run compatibility and performance tests soon. Please stay tuned for updates!

Of course, regarding the temperature-compensated oscillator and femtosecond-grade oscillator versions we’re planning to launch, feel free to share your thoughts here or contact us at [email protected].

Wishing you all the best.

Thank you very much!

 

[Fredy]

Hi everyone, I bought the U2 Pro last week, I don't expect any surprise, my DAC is PS Audio Direct Stream Junior which has I2S input, U2 Pro can exactly couple to my DAC in I2S mode. I connect this little monster directly from Soundgenic NAS > USB > Douk U2, Wow, it sounds super, very organic, much better than streaming. The new Xmos 316 really shines, this little monster totally uplift my system.

Then I tried to connect iphone, iPad usb, ipad lightning + adapter, they all work perfectly.

This afternoon, I DIY a USB cable, onr side is iPad, the other side has 2 cable, one data cable to Douk U2, another cable to power supply, wow, the sound is further improved.

 

[Douk Audio]

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.

 

[NTTY]

I guess the output load is also to be respected (15pf)?
And I would personally go for the best phase noise (highest attenuation), as I think it is more important than 10 or 2ppm.