microRendu Measurements Thread

[Amir_Majidimehr]

@andybob

You don’t know what tests the developers performed. No measurement can tell you that. Please try to avoid this kind of unwarranted conclusion as it lowers the quality of the discussion and reduces the prospects of a response from the developers.

Sorry, I assume everyone knows my history of testing of other products from John Swenson. He has produced another project, a USB device called the Regen. As here, I found through my measurements that it degraded performance when used as intended. And again like this round, usage of my lab supply cleaned up the problem. I then met with him and his sales person Alex and rocky mountain audio fest (RMAF). We spent a good hour together and during that time I realized that he doesn’t have any audio measurement tools. And that his day job is a digital designer in unrelated field so he did not have access to such equipment at work either.

Perhaps he now has such measurements and will post the results. Until then, my assumption is that no one would would measure this combo would recommend it for sale to audiophiles. A 30 db increase in mains noise and harmonics is no small matter.

I was surprised at how little switching power noise came through from your laptop. The whole point of using an Ethernet network endpoint is supposed to be to avoid the noisy computer environment, yet your measurements suggested it would be better to have a laptop next to the DAC than a specialised device. The only other laptop measurements I’m aware of were these ones by Archimago. He speculated that the increased noise for the Aspire may have arisen from increased processing.

Good USB DACs, even bus powered ones like the iFi DAC that I used, have post regulators that clean up the USB power. There is no reason or excuse for power supply noise to bleed into their output. And this is a low end DAC. I expect high-end audiophile USB DACs to be totally insensitive to such things. Please see the measurements of my Berkeley Alpha USB bridge driving my DAC here: High Performance PC Server Interfaces (Async USB) | Audio Science Review (ASR) Forum

Those measurements were with my then Sony laptop driving the DAC. We see no evidence of the kind of noise that is present in microRendu. Performance is superb across the board. See this graph: http://www.audiosciencereview.com/forum/index.php?attachments/mark-levinson-502-hdmi-input-vs-berkeley-vs-audiophilleo-png.7/

I would immediately return any high-end USB DAC that is not immune to source/computer USB vagaries, noise, etc.

Indeed by using a low-end DAC here, I am giving these devices every chance to show that they can reduce noise. Yet what we see at best is no difference and at worse, degradation.

The marketing of audio tweaks has done a disservice to consumers by creating such worries and then selling products to fix them. They may be right but where are the measurements? Noise is trivial to measure. Why not demonstrate such facts? Where are all the measurements of laptops having noise injected into high-end DACs? I have not seen such.

I use a BRIX as a server for Roon and have avoided putting it next to my DAC because of concerns about power or processing noise. I initially ran a 5m USB to the DAC, later used a CuBox-i (switching supply) and now the mR (iFi) as NAA for Roon/HQP. It would be interesting to compare measurements of all four configurations.

What is your DAC? I would start with its measurements through its USB port. If it excellent, then I would not worry whatsoever about using it direct.

You should only use these devices if you need to put them far away from your computer server. Otherwise, you are buying yourself less reliability and extra expense.