Search found 4 matches

by Gary
Wed Sep 05, 2018 1:45 am
Forum: Stereo soundcard for the Raspberry Pi
Topic: RCA outputs spurious signal - solved
Replies: 0
Views: 399

RCA outputs spurious signal - solved

I am using the 'play -n -c2 synth 10 sine 1000' app to create the signal. When I turn the output pot all the way up, there is a spurious signal riding on the output signal. It is 0.3-0.5Vpp and approximately 520kHz. It persists after the signal stops for 4 seconds or so. I just need to turn down the...
by Gary
Tue Aug 28, 2018 11:39 pm
Forum: Stereo soundcard for the Raspberry Pi
Topic: Relative phase
Replies: 0
Views: 388

Relative phase

I am using the audioInjector in a phase sensitive application with quadrature left and right line in. The problem is, the relative phase of the two input channels seems to vary slightly with time. I am also using the headphone output at the same time. Is it possible that due to running input and out...
by Gary
Tue Aug 28, 2018 9:03 am
Forum: Stereo soundcard for the Raspberry Pi
Topic: pi audio?
Replies: 0
Views: 340

pi audio?

Is it possible to use either the HDMI or analog jack audio on the pi along with the audioInjector card? I need a second output stream. If not, I will have to go with a usb audio card.
by Gary
Tue Aug 28, 2018 8:59 am
Forum: Stereo soundcard for the Raspberry Pi
Topic: Crosstalk
Replies: 0
Views: 274

Crosstalk

I am noticing some cross-talk between the headphone output and the line in. Using a FFT program there are harmonics of the headphone fundamental audio tone seen on the input. I guess I noticed this before when I was running the audioInjector-test.sh script when I had no cables connecting the line ou...