Do Headphones cause damage to PHAT DAC?


#1

Does plugging in headphones cause permanant damage to a PHAT DAC card?

I was using headphones at first and not getting any sound after doing all the setup steps I could find. I have the PHAT DAC plugged on top of a PI3.

I then tried to see the output of the card on a scope (A Bitscope plugged into a Pi2 with an official touchscreen, ala Ben Heck Bitscope mod), and did not see any audio waveforms. Granted, I’m not that experienced with the Bitscope yet, but I have used other oscilloscopes.


#2

Most likely the sound is not routed adequately. But for us to be able to help you need to tell us more about the steps you have followed thus far, and whether you are using Raspbian with or without software additions.


#3

OK, I bought 2 PHAT DAC’s.

I soldered the headers on and plugged one onto my PI3 with the Official Foundation display attached.

I burned a Raspian 5.27.16 image onto my 32GB card and put it in the pi.

I fired it up and went through all the raspiconfig stuff through the GUI. Wifi country, keyboard, time zone, etc.

I ran the script in the tutorial “curl -sS get.pimoroni.com/phatdac | bash”

I then ran it again and got the speaker test routine. I was only getting the “Front Left” audio. I found that I needed to plug the yellow instead of the red from my 3.5mm cable to RCA plugs into the right channel on my amplifier.

I went back and tried the original PHAT DAC, and it’s not damaged, I get the “Front Left and Front Right” sounds out of my amp now.

I copied an .mp3 file to /home/pi/music

I opened a terminal window and cd’ed to that directory. typing “dir” there shows my .mp3 file.

I then typed omxplayer “file name”.mp3. It looks like omxplayer is starting as it gives me some stats, but I hear nothing. I assume that omxplayer is not routed to the DAC, and I have no idea how to do that. I see that

“omxplayer -o hdmi example.mp3” will set it to HDMI and

“omxplayer -o local example.mp3” will set it to local (according to the www.raspberrypi.org/documentation/usage/audio/)

But since the PHAT DAC is now the output, how do I play my file?


#4

omxlayer does not support ALSA, so you won’t be able to route audio to the pHAT DAC (or any other source but the integrated card for that matter).

there are plenty of alternatives that will work for playback of mp3 though, for example mpg321.


#5

Suggestions for an ALSA compliant H264 player? Have refreshed an old bbc iplayer project which revolved around OMXplayer and now have added phatDAC am all muddled. Tar muchly!


#6

Or perhaps I could just try looking under this handy traffic cone…