Decent audio adapters.

[richms]

I have tried 2 of the cheap USB-Stereo audio adapters on my PC in anticipation of this mod. And to say they were crap is an understatement. Noisy and artifacty output making them totally unusable. One of them looked just like the one used on here.

So are there any other _good_ audio adapters that are compatible? How about a digital output? That would solve all the problems (Unless they are 48kHz only and some sample conversion happens)

[mightyohm]

I'll admit that my router + USB-audio adapter setup is FAR from audiophile quality. There is a fair amount of digital noise that makes it onto the audio output.

I haven't really tried to solve this, but it should be doable with some extra filtering and bypassing on the USB-audio adapter.

I'm not aware of a better audio adapter that is supported by OpenWrt, but then again I haven't looked either.

[richms]

I got a xitel MD-Link AN1 which is quite old and aimed at recording from a PC to minidisc (how quaint and retro) but it sounds _awesome_ compared to any others i have tried. Not had a go on the asus yet, its full of bluetooth packages at the moment from trying to mess with that, but will have a shot later to see if it works for that. No clue how to check supported sample rates from within windows. But slowly slowly things will progress on this project now

[mightyohm]

If you have a machine running Linux you can use it to check the sampling rates (they will show up in dmesg when you attach the device), but that's pretty much the same thing you'll see on the router when you try it out. In this case, an older adapter might indeed be better, as in addition to better audio quality, it might be more likely to be supported by the Linux kernel drivers on the router!

I found a list of OSS devices here, not sure how complete this is but it might be interesting to look at if you're shopping around for devices (if you also happen to know what chipset they use):

http://manuals.opensound.com/devlists/Linux.html

[denix]

Has anyone tried connecting USB speakers directly? There is currently a deal on Logitech Z5 at J&R:

http://www.jr.com/logitech/pe/LGI_980000168/

[richms]

Code: Select all

usbaudio: device 3 interface 1 altsetting 4: format 0x01000010 sratelo 4990 sratehi 55010 attributes 0x00       
usbaudio: device 3 interface 1 altsetting 5 channels 1 framesize 3 configured                                   
usbaudio: valid output sample rate 4990                                                                         
usbaudio: valid output sample rate 55010                                                                        

Hope that means anything in between - have confirmed on windows its happy with 8000, 44100, 48000, 16000 and 24000 which is prettymuch all that you ever see in streams anyway.

[richms]

Its working now, but the level is way down on the same stream being played on the same device in windows - the volume in mpc is 100% and thats as high as it goes to. I edited the mpd.conf so that the oss mixer was /dev/sound/mixer which is there and has the same numbers as the one that appears from usbaudio when it creates it upon plugin.

So is there any way to make sure that the mixer is set to full volume? I have a feeling its not since its probably about 20dB down on what it should be. Is there something I can echo into the /dev/sound/mixer device to make it full?

[mightyohm]

I don't think so, I looked into this briefly when I was originally playing with the router and I think that /dev/sound/mixer is a binary device and requires more than a simple redirect to change settings.

[richms]

using alsamixer gets the levels up, but it certainly doesnt sound the same as the same device on windows 7 with foobar2000. Much loss of clarity it seems, and thats even on flac files that I have on the USB stick so I think its getting some poor processing going on somewhere along the way or the hardware is inited differently between the 2.

Needs more testing which I dont really have the time for at the moment. Since I have too much on at the moment I will be shelving the project for a bit anyway.

[mightyohm]

D'oh, sorry to hear your tests didn't go well.