Review and Measurements of Weiliang Audio 2019 DC300 DAC

[Mittomen]

You need a crying wolf figure (headless is so cruel).
Thank you for your work!

 

[VintageFlanker]

If you somehow managed to persuade them to send a unit to you, you should ask for the AS-1 DAC. It is supposed to be a dig on ASR (AS = Audio Science). Let us see if Kingwa can actually engineer good stuffs or it was all talk.

Assuming Kingwa is already aware of the bad publicity ASR did for AGD, I don't think the guy is gonna send something to be measured here anytime soon.

 

[777]

Jitter test ?

 

[Ralf Stocker]

The spikes you see in the FFT is the howling of the wolves
Here you can see again that it is not enough to solder some expensive components together. Decades of experience and a good engineering degree are necessary to bring good equipment to the market.

 

[Tks]

Awesome review! It's nice to see another user, and especially in the East to test products we might otherwise never have a chance to even know about. Thanks you :}

 

[Matias]

@WolfX-700 now only if you could optimize the size and placement of the first picture it would show on the first page of ASR.

 

[Kane1972]

I'm sorry to be the inspiration for someone to spend their hard earned money on something that turned out to me a lemon. However, this is a valuable lesson to us all, definitely stick to the devil you know etc.

 

[trl]

Some here on this listing:

https://www.ebay.co.uk/itm/Finished-Hiend-Remote-Dual-ES9038PRO-HIFI-DAC-with-OLED-display-LME49710-opamp/123890802498?_trkparms=ispr=1&hash=item1cd8779f42:g:uOcAAOSwvLJdZ81z&enc=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&checksum=1238908024988e6200ec55764e288991cc985c9ac55f&enc=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&checksum=1238908024988e6200ec55764e288991cc985c9ac55f

Perhaps someone can comment on the placement of the 100MHz master clock...

Everything looks OK inside, distance from DAC's and analogue components till transformers is generous, plenty of caps to get rid of the ripple & noise, so not sure what might be wrong there. Perhaps the MUSES03 makes no sense to place them as output buffer for the RCA/unbalanced output, given that manufacturer designed these opamps for the I/V: https://www.njr.com/semicon/PDF/MUSES03_E.pdf/. Of course, these opamps might be fakes, like some of the caps from there, but can't be sure of that without a much closer look.

Probably DAC's outputs are not paralleled, but still having the 2nd harmonic to 90dB away from the main sine should be caused by the analogue parts, so I wonder if the 4 opamps (probably 49710) can be swapped with original NE5534 or LME49710 and test re-done. Who knows, maybe even the 49710 are fakes.

I wonder if placing that quartz clock nearby the PSU might affect the output so much...or the PCB traces?!

 

[restorer-john]

Everything looks OK inside, distance from DAC's and analogue components till transformers is generous, plenty of caps to get rid of the ripple & noise, so not sure what might be wrong there.

To me, the master clock is too far away from the D/A converters. Unequal length tracks to two D/As no doubt back to a 100MHz clock- not a good idea in my book.
Why go to all the trouble of laying out the analogue left and right separately, and then cross the left and right outputs over each other for the XLR and RCA? Makes no sense.
We have no idea about the micro running the control/display- it's on the front panel PCB and is likely to be getting its power from the multipin connector right next ot the D/A converters. Why isn't it fed from its own supply direct instead of running across the PCB? Is it causing all the noise and problems? Does it properly "sleep" is it awake all the time?
It's just a waste of really nice components unfortunately.

 

[RayDunzl]

https://www.ebay.co.uk/itm/Finished...=1238908024988e6200ec55764e288991cc985c9ac55f

Longest URL ever?

$ wc

xttps://www.ebay.co.uk/itm/Finished-Hiend-Remote-Dual-ES9038PRO-HIFI-DAC-with-OLED-display-LME49710-opamp/123890802498?_trkparms=ispr=1&hash=item1cd8779f42:g:uOcAAOSwvLJdZ81z&enc=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&checksum=1238908024988e6200ec55764e288991cc985c9ac55f&enc=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&checksum=1238908024988e6200ec55764e288991cc985c9ac55f

2 1 1854

No, only 1,854 characters

 

[digicidal]

As long as everyone gets their click... it's all relative.

 

[restorer-john]

Longest URL ever?

I have no idea why it was so long- I just copied the address bar URL and pasted it in. Thought to myself, WTF?

 

[Killingbeans]

If you delete '?_' and everything following you'll get an equally functional URL

 

[Veri]

If you delete '?_' and everything following you'll get an equally functional URL

Yup. Works pretty much always.

 

[maxxevv]

Disappointing to see such dismal measurements on a dual chipped design. Thanks for fulfilling the curiosity of a lot of people though !

Looking at the measurements, seems that it has some serious issues with harmonics when it comes to THD and FFT measurements.

Anyone with insights into what might be the most common reasons for these manifestations in DACs ?

If you do an eBay search for 'Dual ES9038PRO' you get lots of no-name listings for the main PCB in this thing. I would not be surprised if the the only "engineering" Weiliang Audio has done is to engrave their name on the enclosure and swap the op-amps.

I could be wrong though.

If you do a longer search on Taobao, there are actually more than 2 designs of dual-ES9038Pro chipped mainboards / DACs. I link here 2 I have seen , there might be others too.

https://item.taobao.com/item.htm?sp...3IL63s&id=569563397923&ns=1&abbucket=3#detail

https://item.taobao.com/item.htm?sp...3IL63s&id=607678045974&ns=1&abbucket=3#detail

 

[WolfX-700]

Disappointing to see such dismal measurements on a dual chipped design. Thanks for fulfilling the curiosity of a lot of people though !

Looking at the measurements, seems that it has some serious issues with harmonics when it comes to THD and FFT measurements.

Anyone with insights into what might be the most common reasons for these manifestations in DACs ?



If you do a longer search on Taobao, there are actually more than 2 designs of dual-ES9038Pro chipped mainboards / DACs. I link here 2 I have seen , there might be others too.

https://item.taobao.com/item.htm?sp...3IL63s&id=569563397923&ns=1&abbucket=3#detail

View attachment 41067

https://item.taobao.com/item.htm?sp...3IL63s&id=607678045974&ns=1&abbucket=3#detail

View attachment 41065

The product of the developer of the decoder you linked has been measured before (before I got 555) (single 9038Pro). The results were very bad. He is not good at dealing with power noise. But I did not measure this Dual 9038 Pro product. He has lost my trust.

 

[maxxevv]

The product of the developer of the decoder you linked has been measured before (before I got 555) (single 9038Pro). The results were very bad. He is not good at dealing with power noise. But I did not measure this Dual 9038 Pro product. He has lost my trust.

You mean the 杰米音研 M2 ? Good to know that you have measured that !!

The layout of that seems pretty poor. The power supply being so close to the DAC chip while the master clock being placed to far away.

The DAD3 seems much better laid out. The power supply is mounted on a separate board from the main chip board and and probably be further isolated with a metal separator shield plate. The Master Clock crystal seems much more appropriately placed too.

 

[WolfX-700]

You mean the 杰米音研 M2 ? Good to know that you have measured that !!

The layout of that seems pretty poor. The power supply being so close to the DAC chip while the master clock being placed to far away.

The DAD3 seems much better laid out. The power supply is mounted on a separate board from the main chip board and and probably be further isolated with a metal separator shield plate. The Master Clock crystal seems much more appropriately placed too.

DAD3

 

[maxxevv]

DAD3

The DAD3 ( not 3X) seems to have the same poor master clock crystal placement. And it seems to be a pretty cheap crystal from what the limited online photos show ?

But I am surprised by your measurements about its power noise though. The power transformers seem nicely separated from the the rest of the board from the picts I can find. I wonder if better (EMI/EMF) shielding might have helped though ?

 

[trl]

I had a similar question and perhaps some answers too; later @restorer-john replied with couple of thoughts.
Feel free to aggregate all of this into a new post if you think it might be usable.