I have an ND5XS connected to a Synology NAS. All wired ethernet.
As far as I can tell, this is only an issue with parts of some vinyl albums that I’ve digitized (using an ART USB Phono Plus). It seems that the ND5XS is sensitive to some type of data source, and it creates a sound like it’s playing out of a transistor radio. I’ve found a few cases where the problem starts with a song midway through a vinyl side, goes on for the next few songs into the next side and then goes back to normal for the rest of the songs on that side. So it’s not limited to whole album sides (which would point to bad initial digitization). I have never found it happen mid song. As far as I know a song either sounds good throughout or bad throughout.
If I go back to the original digital FLAC files (before breaking into track files) they sound fine when I listen on my computer. Then, after converting to track files, I can access them from my NAS and they all sound fine going through other streamers such as Naim Mu-So. The files that sound tinny “look” to be the same as the ones that sound fine. All are flac format, sample rate 44.1 kHz, and bit rate varies from file to file - but good sounding can have lower bit rate and lousy sounding can have higher bit rate.
Any suggestions on what I could look into to figure out what’s causing this?
What bit depth are they recorded at? 44.1/16 or 44.1/24. If 24 bit then it might be the way the hires header is packed, I have had issues with this on some UPnP renderers did not like the 24bit packing used.What are using as your UPnP server software? Try and see if you can change this to transcode the streams to wav and see if it helps. If your doing this already then perhaps try transcode them again using another app to see if it fixes it. As long as you stay with flac or other lossless files it won’t effect the sound quality as you loose nothing with transcoding lossless to lossless.
Bit rate has nothing to do with sound quality or playback on flacs so don’t worry about that. Its not like lossy MP3 or AAC. It’s just the level of lossless compression will be different on each files so it’s smaller or larger for each one. What flac level did you use , did you have a choice. Standard is level 5 with zero the least. The more compression the more CPU resources it takes to decompress them.
@mikeor
What recording hardware and software are you using?
What audio processing software are you using?
Have you tried playing the ‘raw’ digital recording file (i.e. before you split it into separate tracks), if this is fine, then the problem is in the software, or software settings, that you used to process the file into separate tracks.
If the data for these track still sounds off, then the problem is in the digital recording, in this case it could be recording hardware, software or software settings.
@CrystalGipsy
The level of compression of FLAC has most effect on the CPU of the computer used to do the compression, and very little effect on the amount of CPU resource needed for decompression (typically only somewhere about 20% more required for level 10 over level 1).
Thanks for the help. It is recorded at 44.1/16. I looked out the raw .flac files for the entire album sides, and if I play them through the ND5XS I can indeed hear the same issue. So, it looks like it’s an issue with the original digital recording (hardware, software or software settings). The other players (e.g. Mu-So) sound OK, perhaps because there is a lot more between the digital bits and the sound from the speaker. So next step is to re-rip some these problem albums to see if I can correct it that way.