What makes One Music Server Sound Better than Another?

@kennyc

"Is the OP asking why better parts and/or superior implementation sounds better?"

Not exactly. Both the servers I recently compared were designed and constructed by manufacturers known for fastidious attention to detail in the areas of power supply, shielding, and isolation, and both were the flagship unit for those manufacturers at the time they were built. Both have "better parts and/or superior implementation". One is a bit older (2014 era.) while the other is a little under half that age. The installation of both servers in my system was exactly the same and included fiberoptic isolation between server and router, and between endpoint and router, which should mitigate electrical noise on the Ethernet lines.

I perceived a bit fuller, tonally richer, and bolder sound from the newer server (which is headed back to the manufacturer for repair), and I am curious what aspects of the design or implementation would result in those sonic attributes being different between the two servers, assuming what I perceive is real and not a bias of some sort. I am trying to understand "why", considering this is a digital signal, one would sound different (and better) from the other, when connected to the exact same receiving equipment?

Based on the discussions I have read here and elsewhere, I am left with the impression that the reasons for the sonic differences are not fully understood but that processing, isolation (mechanical and electrical), and power supply are likely affecting the digital signal (maybe wrt to timing and lower jitter) that is received by the endpoint, and that these effects result in a slightly different analog presentation after the signal is converted in the DAC. In short, it seems the better designers have improved their implementations over the years so I should trust what I hear and purchase what sounds good to me, not unlike most stuff in this hobby.

Thanks all for the responses.

So much commentary. Have you considered trying a roon nucleus?

It's a computer yes. But if you couple that with a decent streamer dac which is where the true value is you should be in pretty good shape. The merits of spending a lot of money on a server are questionable in my opinion. 

So much commentary...The merits of spending a lot of money on a server are questionable in my opinion.

Actually, if you take a look mitch has a perfect purchase/sale record on A’gon of 568 (i.e., experienced).  Doesn’t seem like excess commentary for an interesting question from someone who walks the walk.  And I’ll bet dollars to donuts he has his own opinion on the benefits of using a server in his system already thought through.

@mitch2

Please confirm this is Roon core/server running on both?

If so its possible different versions of Roon are running on each. If so, tehn its very possible the resulting sound could be somewhat different.

Even if same version running on exactly same OS on both, then next thing would be to make sure all Roon setting that affect sound quality (everything short of any added user defined DSP) are the same, for example volume limiting and any other parms that may affect the streaming. I know there are many that may be somewhat different with version but can’t list them all off the top of my head.

Of course an easy first check to compare is to examine the streaming pipeline in play using the Roon endpoint. Is the processing exactly the same in both cases being compared? If not that alone could very well result in a difference in sound.

Assuming streamer is similarly isolated from any network noise (from server of any other devices attached to the same network) as you indicate, and assuming you are using Roon to stream in both cases, changing only Roon server/core hardware my bet would be differences in teh Roon software implementation on each is most likely to result in significantly different sound.

Doesn’t Roon have their own optimized version of Linux (Roon OS) optimized for Roon? Do both servers use that? That would seem to be the best choice of OS to run Roon core/server on.

I run Roon core/server on WIndows.  Not optimal, but still works pretty well and sounds very good.   I might move to an appliance with Roon OS someday just for kicks.  I removed a lot of unneeded programs on my Windows PC and turned off a lot of resource hogging features  to help make Roon happy running there.  My only issue is periodic slowness with the GUI.   All my Roon devices connect over very strong Wifi.

Mysteries.....cheers!