This is a review and detailed measurement of one of the myriad of boards on ebay sporting the WM8740 DAC chip. It was kindly purchased and drop shipped to me. The listing has expired but it seems that it cost US $48.
What you get is well, a bare board:
And not a clean one. The PCM 2704 on the bottom right was either reworked on this board or lifted from another product in the past. Other ICs are also dirty which could be indication of used parts or grungy assembly.
Speaking of PCM 2704 that is an all-in-one USB DAC! It is used here only to generate S/PDIF output from USB, leaving its DAC functionality behind. Sad as that alone would have done the job probably as good or better than stringing it to WM8740 DAC chip.
On first try, I could not get the board working. It comes with no manual, instructions or even vendor name/address. I fed it 9 volts, it did not work. I fed it 12 volts, it did not work. Then I realized it says that the input is AC, not DC! With AC input it worked fine.
The one switch is power and the other selects between S/PDIF and USB Input. An LED lights up when the power is on.
DAC Audio Measurements
As usual we start with our dashboard:
Boy, what a let down. The WM8740 is rated at 104 dB SINAD (albeit, with a-weighting). We are an entire planet away at just 78 dB, landing this port in the our red category of all DACs tested:
Signal to noise ratio is not bad given our expectations from above:
IMD distortion relative to level shows both elevated noise and early onset of distortion:
The linearity test tells me that 24 bit samples are being truncated to 16 bits:
This is an odd problem I run into with some DACs due to ASIO4ALL interface I use in Windows. So likely the blue graph is the representative performance.
I ran jitter test but it was with USB so it is not that valid. So I am not going to post it.
My 32-tone test signal resembling "music" is encoded at 192 kHz sampling. I could not get this board to pay it either with S/PDIF or USB. So I resorted to my 7 tone signal which runs at 44.1 kHz:
Conclusions
I can't tell if all the boards sold come with shoddy construction of this one. But even if they are not, you are getting way less performance than commercial DACs at slightly higher price but with case, power supply, warranty, etc. I have yet to get lucky with any of these "ebay buys." They are sold on basis of what is in them, rather than how they measure and perform. And so far, universally, they don't perform. Please stay away.
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As always, questions, comments, recommendations, etc. are welcome.
Was watching the cooking show and they were making a dish with foie gras. One of the panthers saw it, told his buddies and they are now asking me to get them a few pounds (!) of this expensive stuff. I am too scared of telling them no. Not because they have teeth but because they could boycott modelling for me. So please donate generously so I can buy them some using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
What you get is well, a bare board:
And not a clean one. The PCM 2704 on the bottom right was either reworked on this board or lifted from another product in the past. Other ICs are also dirty which could be indication of used parts or grungy assembly.
Speaking of PCM 2704 that is an all-in-one USB DAC! It is used here only to generate S/PDIF output from USB, leaving its DAC functionality behind. Sad as that alone would have done the job probably as good or better than stringing it to WM8740 DAC chip.
On first try, I could not get the board working. It comes with no manual, instructions or even vendor name/address. I fed it 9 volts, it did not work. I fed it 12 volts, it did not work. Then I realized it says that the input is AC, not DC! With AC input it worked fine.
The one switch is power and the other selects between S/PDIF and USB Input. An LED lights up when the power is on.
DAC Audio Measurements
As usual we start with our dashboard:
Boy, what a let down. The WM8740 is rated at 104 dB SINAD (albeit, with a-weighting). We are an entire planet away at just 78 dB, landing this port in the our red category of all DACs tested:
Signal to noise ratio is not bad given our expectations from above:
IMD distortion relative to level shows both elevated noise and early onset of distortion:
The linearity test tells me that 24 bit samples are being truncated to 16 bits:
This is an odd problem I run into with some DACs due to ASIO4ALL interface I use in Windows. So likely the blue graph is the representative performance.
I ran jitter test but it was with USB so it is not that valid. So I am not going to post it.
My 32-tone test signal resembling "music" is encoded at 192 kHz sampling. I could not get this board to pay it either with S/PDIF or USB. So I resorted to my 7 tone signal which runs at 44.1 kHz:
Conclusions
I can't tell if all the boards sold come with shoddy construction of this one. But even if they are not, you are getting way less performance than commercial DACs at slightly higher price but with case, power supply, warranty, etc. I have yet to get lucky with any of these "ebay buys." They are sold on basis of what is in them, rather than how they measure and perform. And so far, universally, they don't perform. Please stay away.
------------
As always, questions, comments, recommendations, etc. are welcome.
Was watching the cooking show and they were making a dish with foie gras. One of the panthers saw it, told his buddies and they are now asking me to get them a few pounds (!) of this expensive stuff. I am too scared of telling them no. Not because they have teeth but because they could boycott modelling for me. So please donate generously so I can buy them some using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/