This is a very simple upgrade that you can do to any amplifier that does not have Bluetooth built in. In my case I will be adding Bluetooth to my Home A/V receiver amplifier. It only takes about 3 minutes and is completely removable should you decide to change your setup in the future.
Step 1: Parts List
1. USB Bluetooth receiver ($3 to $10 Ebay or Amazon (I recommend getting one that has V4.1+EDR its gonna give you better sound quality)
2. USB Charger ($1) Ebay or Amazon
3. RCA to 3.5 mm audio cable ($2) Ebay or Amazon
4. Audio Video stereo receiver amplifier ( or any amplifier with RCA input )
Step 2: Making Connections
Start by finding a unused RCA input on the back of the A/V receiver that you could use for Bluetooth. If all are being used it is possible to use the auxiliary input on the front of the unit, however you will likely need a different cable for that. I choose the CD to use as my Bluetooth input and plugged the RCA cable into it and on the other side connected it to the USB Bluetooth adapter. Next plug the USB Bluetooth adapter into the USB charger and plug it into an outlet. Its a good idea to plug the A/V receiver and USB charger into the same switched surge strip so you can flip power on or off to both at the same time.
Step 3: Pairing
All that's left is the pairing of the Bluetooth adapter with with any streaming device that you prefer. I used my cell phone which happens to be android but even with apple devices the setup is about the same. Simply go into your phone settings and turn on Bluetooth and it will automatically scan for any Bluetooth devices within range. (Bluetooth has a range of around 30 feet) The Model of the Bluetooth adapter should show up under available devices. (mine showed up as EC502) Once your device finds it just click on it and it should move to paired devices and also say connected next to it. If your A/V receiver is on you will hear a pairing sound from the speakers which means your have successfully paired your device to the A/V receiver. Congratulations your all done! enjoy your tunes via Bluetooth on that A/V receiver amplifier.