100 Ohm Resistor on Display SCK is Not Eliminating Audio Noise?
dwestbury opened this issue · comments
I was hearing the popping and static noise that others were complaining about, so I went ahead and cut the PCB trace for the display clock (SCK) and added in a 100 Ohm resistor as noise reduction bridge, but to my ears there's nearly no difference?
Curious whether any other potential sources of noise are being investigated? In my case it's not terrible, but it is clearly perceptible.
Hello Darrell, are you sure that you've cut completely through the SCK track? I've compared before and after, and the resistor does make a significant reduction in noise.
Yes, I'm sure because I actually peeled off the section of the copper trace leading from my cut on the board to the SCK pin.
Another area I need to investigate as a possible noise source is the dupont connector I made, so I can remove the teensy, rather than soldering it directly to the PCB.
It looks like I have the same problem here. The resistor is in place but the noise (volume independent) is still there.
It look like it soming from any kind of computer USB. With a powerbank away from the computer it is not there.
Any solutions so far ?
If it goes away when you change the power source, then it's coming from that. Be careful with ground loops.
I can confirm that the V1.3 PCB which has a slightly re-routed display SCK track with a 100ohm resistor, is much quieter. Bypassing the 100ohm resistor increases the clock noise significantly.