I all I'm new to this forum but looking forward to learning a lot from this site.

I'm working on a DIY bluetooth speaker project. Since I am new to this stuff I've just been buying random parts online. In my head everything seems straight forward however when I finally got every thing connected I'm running into a speaker static issue.

The issue arrises when I connect my aux cable from the bluetooth receiver to the amplifier. The second I do that the static starts. This is illustrated in the first picture (One Power Source Aux Cable.png). As you can see I have everything connected to one 11.1v power source. The amplifier is a 12v and the bluetooth receiver is 5v so I need to have a regulator to drop the 11.1v to 5v.

If I connect the bluetooth receiver to a separate power source I don't get the static and the audio play just fine. Does anyone have any suggestions at what I might be doing wrong. Is it the regulator? is it the speaker? Hope this is enough information. I don't know all the terminology but hopefully I make sense. Please let me know if you need more details.

Details about my hardware:
Turnigy 2200mAh 3S
https://www.amazon.com/gp/product/B0072AEY5I/ref=od_aui_detailpages00?ie=UTF8&psc=1
DROK Ultra Small Hi-Fi 10W+10W Dual Digital Audio Amplify
https://www.amazon.com/gp/product/B010LKFXVY/ref=od_aui_detailpages00?ie=UTF8&psc=1
DROK LM2596 Numerical Control Voltage Switching Regulator
https://www.amazon.com/gp/product/B00BYTEHQO/ref=od_aui_detailpages00?ie=UTF8&psc=1
DROK Portable Wireless Bluetooth Audio Receiver
https://www.amazon.com/DROK-Bluetoo...coding=UTF8&psc=1&refRID=CQA5WMSF331B0JF87VHS
DROK Mini 5W Stereo Audio Speaker 2" inch Hifi Speaker
https://www.amazon.com/gp/product/B00LSEVA8I/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

 

If you listen to the receiver with headphones does it sound ok?

Please describe the nature of the feedback and static.

 

I suspect the cause is injected noise from the switching regulator. I suggest using a linear regulator to get the 5 volts for the bluetooth receiver as it will not take much current.

Les.