Hi lcbl75771
Thank you for posting in the community!
You are absolutely right, there are hundreds of manufacturers for Bluetooth adapters these days, and it can be hard to sort through the different types. I can recommend that you make sure the correct Bluetooth profiles are included in the adapter. The main one would be A2DP which allows for stereo audio transmission. The other one would be AVRCP which allows controls from the adapter to the mobile device. Perhaps one of the users can recommend a particular brand they've had success with!
Warm Regards,
Tony A - Community Support
I too am looking for a Bluetooth adapter for my series 2 sound dock. Did you have any luck finding a decent adapter?