problems interfacing with 16 bit DAC

asilker

For a couple years I've been using the Starting Point Systems DAC3 unit (or battery DAC as it's referred to on HeadFi). It's a 16bit DAC which utilizes a Phillips 1543 multibit chip. [Info on the unit here: http://audio.starting-point-systems.com/ ]

Runeaudio will play music through the HDMI or 1/8" jack, but when I select my DAC via USB, the DAC flutters its input led but then music does not play. Is there anything I can do?

[ RPI b 3 with the v0.3-beta (23/03/2016) release ]

EDIT: I have tried swapping through all sound signature options and rebooted a bit. Didn't affect anything.

hondagx35

Hi asilker,

we need more info to help.
- did you try different files (Mp3, FLAC, WAV ....)?
- did you check the debug info while playing music through USB?
- Is your DAC "USB Audio 2.0 compliant"?

You can try it with a more recent kernel version, see here.

Post the output from:

cat /proc/asound/card*/pcm*p/sub*/hw_params

while playing music to your DAC.

Frank

asilker

Hey Frank,
happy to describe:
- I only tried FLAC of different bit depths. I will try MP3 and WAV next.
- I did not check debug. Will do that.
- Yes, my DAC is USB 2.0 compliant.
- I am installing the more recent version now, you recommended that in my last thread as well and while I was able to get the 2016 version to work, but I should get off my duff and use the more recent firmware.

Thanks for the pointers, I'll report back later. As always, I appreciate the support.

Tony

asilker

Ok, I have installed the suggested version. Wifi save function does work much better BTW (you were right)

I put an MP3, FLAC, and WAV file into the play queue. The hardware behavior is the same for each file type:
Input led on DAC blinks, file does not play, and I get 3 messages that Rune is changing audio output device. All 3 files play fine through HDMI or 1/8" out.

I am having trouble finding the code you mentioned in your first post here. Could someone help me figure out what I'm looking for in the debug code?

hondagx35

Hi,

you have to get access to the console and enter the command:

cat /proc/asound/card*/pcm*p/sub*/hw_params

Frank

- Get access to the console:
Use SSH from your PC

If you are not familiar with SSH read this for Windows or this for Linux/MacOS
The default login for RuneAudio is "root" with the password "rune" (without quotes).

- Use sftp to access files on Rune Audio:
Get WinSCP from here and install it.
When it opens setup the following:
- Session
File Protocol: SCP
Host name: The IP address of you Raspberry Pi
User name: root
Password: rune

That's it, connect and you can transfer files just by dragging and dropping.

asilker

Alright I'm set up with putty and things are connecting. Here's what I've got

root@runeaudio(rw):~# cat /proc/asound/card*/pcm*p/sub*/hw_params
access: RW_INTERLEAVED
format: S16_LE
subformat: STD
channels: 2
rate: 44100 (44100/1)
period_size: 4096
buffer_size: 16384
closed
closed
closed
closed
closed
closed
closed
closed
closed

EDIT: ps I am also set up withWinSCP

Frost_dk

Hi
Could it be so simple, that the usb output is muted In alsamixer?
I have experienced it a couple of times when connecting some dads.

Just write alsamixer and push F6 and select the right output. Then push the button "M" to toggle between muted and unmuted.

Br

asilker

Frost_dk wroteHi
Could it be so simple, that the usb output is muted In alsamixer?
I have experienced it a couple of times when connecting some dads.

Just write alsamixer and push F6 and select the right output. Then push the button "M" to toggle between muted and unmuted.

Br

Tried this today. Was able to select the DAC as my soundcard and see adjustment options for it, but when I played music (muted or unmuted) I immediately got the message:

"The sound device was unplugged.
Press F^ to select another sound card."

Another thought: my DAC has an independent reclocker built into it. I know almost nothing about clocking protocol and function, but could the RPI and DAC both be trying to control the data stream? (I believe this means my DAC is asynchronous)

hondagx35

Hi asilker,

is your DAC powered via USB?
Check the log files (Menu->Debug) for messages from USB.

Frank

asilker

I'll do that next.

Today I went back and checked through my settings on Foobar. For this DAC, I must use 16 bit output, and with the 24 bit output the system refuses to send information to the DAC, even when the files are redbook. I wonder if this is the issue with Rune as well. Is there a setting to change output bit depth?

hondagx35

Hi asilker,

Is there a setting to change output bit depth?

Yes, there is. Please read #324137
If this works i will help you to make it persistant.

Frank

asilker

Ok Frank, here we go

To answer your first question, my DAC is powered by a wallwart power source. It should not be taking power from the RPI.

Second, I followed the protocol outlined in your link. Changed the mpd.conf file to add format "*:16:*" in its correct location, and then rebooted MPD as per the command prompt. With this modification I was able to navigate through my library and queue songs, but the same issue persisted (a few flashes, 2 seconds of play time, and then stopping).

janui

Hello asilker,
Just a thought... There are two versions of the 1534 chip. There is the TDA1543 with I2S or "European format" audio input and the TDA1543A with Left Justified or "Japanese format" audio input. If it's a TDA1543A, this could be causing the problem. I see there is a line in an earlier post with the text "format: S16_LE", the important part of this is the "LE" (little endian) which makes the output I2S. Changing it to "format: S16_BE" (big endian) makes it left justified. You may be able to simulate BE/LE setting using a PC with Foobar or you could just take the cover off the DAC to check the chip type.

If it's a TDA1543 (without the A) then the line "format: S16_LE" is correct and you can ignore this post.

Janui