Hi all,
This is my first post here, so I'll begin with a big thanks to Paul and the community contributors for a great and fun development platform.
Here is a small problem I noticed with the Teensy 4 Audio board. I use the headphone port to connect to an external amplifier. The sound is good when operating normally, but when unpowered it emits a loud hum. Presumably in this state the headphone outputs are floating in such a way that the Teensy and any attached cables are acting like a big antenna for ambient 50Hz mains noise.
I managed to fix this problem by adding two 1k resistors from both HPL and HPR to HPVGND. I figure that this provides a return path for any induced electrical noise, without significantly decreasing the load resistance. Seems harmless to me, but is there a better approach?
Cheers,
Stewart
This is my first post here, so I'll begin with a big thanks to Paul and the community contributors for a great and fun development platform.
Here is a small problem I noticed with the Teensy 4 Audio board. I use the headphone port to connect to an external amplifier. The sound is good when operating normally, but when unpowered it emits a loud hum. Presumably in this state the headphone outputs are floating in such a way that the Teensy and any attached cables are acting like a big antenna for ambient 50Hz mains noise.
I managed to fix this problem by adding two 1k resistors from both HPL and HPR to HPVGND. I figure that this provides a return path for any induced electrical noise, without significantly decreasing the load resistance. Seems harmless to me, but is there a better approach?
Cheers,
Stewart