For years now, all my streaming has been via Universal Plug-and-Play “DLNA over Ethernet.”
The McIntosh equipment I’m currently using has an on-screen display that, in addition to showing you the cover art and time-track of the cut you’re streaming, also provides information on what format is being streamed. Now since virtually all my music is ripped to 44.1, 16-bit WAV, the format should always display (in McIntosh speak) as “PCM.” So imagine my surprise when some of my tracks occasionally displayed as being “MP3 320.”
I originally accused McIntosh of the conversion, but they couldn’t reproduce what I said was happening & recommended that I look at my server settings. Sure enough, buried in the preferences, there were two DLNA settings. The first was for “Convert format when needed” and this was set by default to “yes.” The second setting was “convert format to” and this was set by default to “MP3 High-bit.” I changed the settings to “no” and “16-bit, 1.44” respectively. Save, exit, and smile in that order.
So back to streaming after a reboot of the laptop and a refresh of the program. What do I see on the display? The dreaded MP3 format again. WTF? Double checked the settings - The changes were as I left them. So I do some internet research. And I find that the UP&P-DLNA standard has no prohibition against format changes. The goal of the standard is to ensure that something comes out the far end of the pipe, and there’s no guarantee that what you receive will be what you sent.
After more reading, it seems that Roon’s “RAAT” standard DOES forbid format changes and that what is received will be a bit-perfect copy of what was sent. So I download, install, and fight the Roon installation (again and again) until I finally beat it down into reluctant functioning. And I then find that the Roon Mac install doesn’t support RAAT. I’ve got to use AirPlay (that is supposed to be inferior to RAAT). But just for giggles, I try some AirPlay streaming and surprise; the McIntosh now claims that everything playing is now “PCM.”
So now I’ve a host of other questions to answer:
How much jitter and how many dropouts am I currently getting via Roon AirPlay?
Is it worth running Windoze in Boot Camp mode on my Mac to get RAAT instead of Airplay?
Now note that if I wasn’t using room-to-room streaming of music over Ethernet, all of this would be academic. But I have noticed that sometimes the same cuts sound better one time than at other times. I’ve previously written it off, assuming that the Gods were crazy, but in retrospect, I now wonder if the change was due to DLNA occasionally giving me MP3 vs. PCM streaming.
So I’m somewhat disappointed at Roon’s shortcomings also (no RAAT support for Mac, and some “Roon-Ready” components are recognized, and some aren’t - Etc.). But so far, Roon is delivering all PCM feeds to my components over Ethernet - my previous music server (that shall remain politely nameless) is not. And that’s the facts.