This is an analysis of Raspberry Pi4 USB signal quality to drive a budget but good DAC without impact on its performance. Traditionally it is thought that one needs a high-end "streamer" to accomplish the same.
Member @DrCWO kindly sent me the above platform for testing. It is a standard single board computer RPi hardware platform with his "RooExtend" Roon image which makes the device an end point for Roon player. This allows Roon to stream (push) content to it just like any other streaming platform. The very attractive hardware/enclosure is from his partner company, audiotra.de.
For testing, I selected the Topping E30 II that I had sitting around which at the time of its review cost US $149. I will be comparing its native, i.e. direct connected over USB, vs remote network (Ethernet) connection through RoonExtend.
Note that I used an independent power supply to drive the Topping E30 II. The RPi/Rooextender was powered using a random 1 amp USB-C adapter I had sitting around (I was also able to power it from my computer's USB hub).
RPi USB Streaming Measurements
As usual, we start with our dashboard:
This performance is identical to direct connect to E30 II in all aspects from noise to distortion, showing full transparency.
Clock jitter over USB is often thought to disturb the performance connected DAC. So let's check for that:
Here, we actually see an improvement! My standard PC is quite noisy so a bit of that noise had bled into the E30 II in the original test. Here, the RPi is quieter, resulting in less noise spikes. Not that any of it is remotely audible, seeing how we are talking about -140 dB interference. But good to see that issue is not even there with RPi host.
Finally, let's run our 32 tone test:
Again, we get identical results.
We could keep going but there is no point. If there was an issue, it would have showed up by now.
Conclusions
A good DAC's job is to deal with vagaries of USB source. There is some possibility of interference over USB ground but as noted, that actually got better in the case of RPi compared to my own computer's. There should be no doubt that you can get the same performance out of these platforms than any other proper streamer. Performance will completely depend on the quality of the DAC than the streamer itself.
P.S. I should compliment member @DrCWO on his efforts to build this RPi, plug and play extender image. And the attractive hardware that his partner is producing. Put a smile on my face as soon as I saw it, and experienced its performance.
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As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Member @DrCWO kindly sent me the above platform for testing. It is a standard single board computer RPi hardware platform with his "RooExtend" Roon image which makes the device an end point for Roon player. This allows Roon to stream (push) content to it just like any other streaming platform. The very attractive hardware/enclosure is from his partner company, audiotra.de.
For testing, I selected the Topping E30 II that I had sitting around which at the time of its review cost US $149. I will be comparing its native, i.e. direct connected over USB, vs remote network (Ethernet) connection through RoonExtend.
Note that I used an independent power supply to drive the Topping E30 II. The RPi/Rooextender was powered using a random 1 amp USB-C adapter I had sitting around (I was also able to power it from my computer's USB hub).
RPi USB Streaming Measurements
As usual, we start with our dashboard:
This performance is identical to direct connect to E30 II in all aspects from noise to distortion, showing full transparency.
Clock jitter over USB is often thought to disturb the performance connected DAC. So let's check for that:
Here, we actually see an improvement! My standard PC is quite noisy so a bit of that noise had bled into the E30 II in the original test. Here, the RPi is quieter, resulting in less noise spikes. Not that any of it is remotely audible, seeing how we are talking about -140 dB interference. But good to see that issue is not even there with RPi host.
Finally, let's run our 32 tone test:
Again, we get identical results.
We could keep going but there is no point. If there was an issue, it would have showed up by now.
Conclusions
A good DAC's job is to deal with vagaries of USB source. There is some possibility of interference over USB ground but as noted, that actually got better in the case of RPi compared to my own computer's. There should be no doubt that you can get the same performance out of these platforms than any other proper streamer. Performance will completely depend on the quality of the DAC than the streamer itself.
P.S. I should compliment member @DrCWO on his efforts to build this RPi, plug and play extender image. And the attractive hardware that his partner is producing. Put a smile on my face as soon as I saw it, and experienced its performance.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
