G+_Paul Hutchinson Posted January 15, 2019 Share Posted January 15, 2019 Shooter_FPV Yep Oaklawn section of Cranston, grew up across the street from the library, my Dad was the minister at the Oaklawn Community Baptist Church from 1967 to 1974. Link to comment Share on other sites More sharing options...
G+_Shooter_FPV (Shooter_FP Posted January 15, 2019 Author Share Posted January 15, 2019 Paul Hutchinson Wow, cool. I grew up in Cumberland, live in East Providence now. Small world... Link to comment Share on other sites More sharing options...
G+_David Peach Posted January 15, 2019 Share Posted January 15, 2019 Some general reading on audio hum: http://120studio.com/audio/fixing-speaker-hum.htm Building filters: arrow.com - Using Capacitors to Filter Electrical Noise | Arrow.com Link to comment Share on other sites More sharing options...
G+_Shooter_FPV (Shooter_FP Posted January 15, 2019 Author Share Posted January 15, 2019 David Peach Thanks! I’ll start reading tonight... Link to comment Share on other sites More sharing options...
G+_John Sullivan Posted January 16, 2019 Share Posted January 16, 2019 For one thing, there's a big difference between a "hum" (low pitched sound) and a "whine" (high pitched sound), so which is it? Another thing is that you have repeatedly said that you only hear the noise when you switch the module to Bluetooth. That proves that it is NOT the amp at fault. When you move your hand near the Bluetooth audio input jack, you are acting like an antenna, as you noticed. Any noise that was being picked up before now is louder. Because both modules exhibit the same behavior, it suggests that the Bluetooth function is picking up some interference from your workroom. Possibly fluorescent lighting or similar (if it's a low pitched hum) If it's a high pitched whine, could be something like an electric motor (fan or whatever) Possibly when you try it at home you will not hear it. As far as grounding the device, it's portable. What are you going to ground it to? You can experiment with connecting various sized capacitors between the yellow wire from the module to the black wire from the module. If you use electrolytic capacitors, be sure to connect the (-) side to the black wire. Other types of capacitors are not polarized and won't care which way you hook them. What you're trying to do is bleed-off the noise to ground (the black wire). Use a larger capacitor for low pitched hum, use smaller value capacitors for high pitched whine. Link to comment Share on other sites More sharing options...
G+_John Sullivan Posted January 16, 2019 Share Posted January 16, 2019 ps. the rectangular blue components on the edge of the amplifier board with offset screws are adjustable resistors. I can't tell what they do by looking at the video, but you should leave them alone. Link to comment Share on other sites More sharing options...
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