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simoncn · 11-01-2014, 19:01

(11-01-2014 03:06)classical11 Wrote: Hi Simon,

Thanks for sharing your observations.

Thank you for sharing yours!

Quote:It's interesting that you've had audio glitches when streaming across the network. Were you using Wifi at either end? Do you get glitches when you disable transcoding?

There is no wi-fi involved. I haven't done a detailed comparison of transcoding vs. non-transcoding. The non-transcoding case isn't of much interest to me because I prefer the sound with transcoding enabled, based on my experience so far.

Quote:What sort of distortions do you hear when you plug in your DAC into the powered USB hub? Are they very noticeable? Could they be related to the hub you are using?

The sound is very low-pitched and appears to play more slowly, and is also "chopped up". I am using the powered USB hub supplied by NewIT in the UK. This problem occurs without transcoding enabled.

Quote:
I haven't had any audio glitches in my setup but there are a few differences to yours. I am using the same DAC (Stoner Acoustics UD110v2) connected to a powered USB hub. However I'm using mpd for playback. Another difference is that I'm not doing any transcoding on the MinimServer end. My files are 16 bit flac and mp3.

I'm unable to use mpd because I haven't been able to make it play a WAV stream. There was a discussion about this some time ago on this thread.

Quote:I can't hear any noticeable difference if I plug the DAC in the Raspberry Pi or in the USB hub.

The MediaPlayer renderer is running on a Raspberry pi with Raspbian hf. On another Raspberry Pi I have MinimServer and it's reading the library off a USB hard drive (connected to a powered USB hub). Both are connected to the network via wired Ethernet.

A few observations:

- MinimServer has been rock solid for the last month or so. I only restart it occasionally to apply updates.

- I don't hear any glitches even when I stream to 3 devices at the same time (2xRaspberry Pis and a Linux PC, all running MediaPlayer, all through wired Ethernet)

That's interesting. It might be because you are using 16-bit non-transcoded streams, or it might be a difference between mpd and mplayer.

Quote:- mpd must be configured in /etc/mpd.conf to use the correct ALSA device for the USB DAC:

Code:

audio_output { type "alsa" name "My ALSA Device" device "hw:1,0" # Use the right device here auto_resample "no" # disable resampling }

Perhaps this is the cause of my sound distortion problem when using the USB hub. I am currently using 0.0 as the device. Should I be using 1,0 instead? How can I find the correct number? Is it significant whether the numbers are separated by a period or a comma?

Quote:- Also, set the mixer type to "software" in order to be able to configure the volume, as Pete described in another post:

Code:

mixer_type "software"

I don't need to do this, as I can use the volume controls on my powered speakers. In general I have found that doing less processing in the audio path improves the sound.

Quote:- I initially had one of the Raspberry Pis running the renderer connected using Wifi but the Wifi drivers were flaky causing it to lose connection every 1-2 days

- MediaPlayer and mpd work very nicely. gapless works flawlessly.

I would like to try to using mpd if I can get it running with WAV streams. Do you have any suggestions for how to do this?

Quote:- I am very satisfied with the sound coming out of the DAC when playing standard definition 16 bit flac files (but I don't have a high end system like a Linn for comparison so this is obviously pretty subjective). I would however like to experiment with transcoding to wav24 at some point.

- I am using BubbleUPnP (and sometimes BubbleDS) for the control points.

Cheers,
Ciprian

I have found a noticeable improvement with wav24 transcoding of 16-bit FLAC files. With wav16 transcoding of 16-bit FLAC files, it's hard to be sure whether there's an improvement.