This is a review and measurements of Pi 2 Design's 502DAC. I was kindly sent by designer and forum member @Michael Kelly. It retails for 109 from his website. He was kind enough to send me a complete system with the requisite Raspberry Pi and Volumio audio operating system. As a result, the unit was turnkey in operation:
I powered it up using a single supply (it allows for dual supplies). Connect an Ethernet cable or use WiFi to get a networked DAC and S/PDIF output.
In my case, since Volumio only supports 16-bit audio from my Roon player (through airplay), I resorted to playing my test files from the USB thumb drive (red and black stick). DietPi supports Roon's RAAT protocol by the way.
Support from Michael has been excellent which is always a plus in my book. He told me that the main application for this device is using it as a networked S/PDIF & AES/EBU interface (to your own DAC). The included analog outputs are a bonus. Toslink is also supported.
Let's measure it and see how she does.
Measurements
I started with measuring the spectrum of jitter and noise from its BNC output:
Here, I am comparing it to the Allo Signature. Compared to that, we have a series of spikes but their levels are exceptionally low at just 1 picoseconds. Comparing to budget desktop products like the Topping D10 (inset), this is excellent performance. This is even more so seeing how this is a networked solution (and hence more opportunity for noise pollution) than a simpler DAC.
Testing the internal DAC using our usual dashboard view we get:
Output is nice at 2 volts. Alas, distortion levels are high relative to desktop solutions and top of the line Pi HATs. SINAD of 86 dB puts it in forth tier of products I have tested:
Measuring jitter from the analog output we get:
Very clean output although the noise floor is higher than more expensive solutions (e.g. Allo Katana).
Conclusions
As a networked digital audio output solution, the Pi 2 Design 502DAC accomplishes its purpose. It has very good jitter response, besting budget S/PDIF converters that don't have networked interfaces. In that specific application, combined with great support from Michael, I recommend this solution as more budget friendly than likes of Allo Signature.
For analog output, the 502DAC works but you can do much better with other solutions. It is nice to have it though for "confidence monitoring" as one uses it with digital outputs.
As always, questions, comments, corrections, etc. are welcome.
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I powered it up using a single supply (it allows for dual supplies). Connect an Ethernet cable or use WiFi to get a networked DAC and S/PDIF output.
In my case, since Volumio only supports 16-bit audio from my Roon player (through airplay), I resorted to playing my test files from the USB thumb drive (red and black stick). DietPi supports Roon's RAAT protocol by the way.
Support from Michael has been excellent which is always a plus in my book. He told me that the main application for this device is using it as a networked S/PDIF & AES/EBU interface (to your own DAC). The included analog outputs are a bonus. Toslink is also supported.
Let's measure it and see how she does.
Measurements
I started with measuring the spectrum of jitter and noise from its BNC output:
Here, I am comparing it to the Allo Signature. Compared to that, we have a series of spikes but their levels are exceptionally low at just 1 picoseconds. Comparing to budget desktop products like the Topping D10 (inset), this is excellent performance. This is even more so seeing how this is a networked solution (and hence more opportunity for noise pollution) than a simpler DAC.
Testing the internal DAC using our usual dashboard view we get:
Output is nice at 2 volts. Alas, distortion levels are high relative to desktop solutions and top of the line Pi HATs. SINAD of 86 dB puts it in forth tier of products I have tested:
Measuring jitter from the analog output we get:
Very clean output although the noise floor is higher than more expensive solutions (e.g. Allo Katana).
Conclusions
As a networked digital audio output solution, the Pi 2 Design 502DAC accomplishes its purpose. It has very good jitter response, besting budget S/PDIF converters that don't have networked interfaces. In that specific application, combined with great support from Michael, I recommend this solution as more budget friendly than likes of Allo Signature.
For analog output, the 502DAC works but you can do much better with other solutions. It is nice to have it though for "confidence monitoring" as one uses it with digital outputs.
As always, questions, comments, corrections, etc. are welcome.
-----
If you like this review, please consider donating funds for these types of hardware purchases using Patreon (https://www.patreon.com/audiosciencereview), or upgrading your membership here though Paypal (https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054).