Bluetooth input through RCA phono plug in 1950s radios

[init4fun]

My following suggestion should only be considered if your willing to use an Isolation transformer with your Crosley , which is a "Hot Chassis" design ;

I would think the best possible sound would come from getting an RCA to 1/8" adapter cable and plugging the line level output of your computer into the Crosley's input. Of course it'd have to combine the L and R stereo output of your computer to the mono input of the Crosley. As in anything else, the less times the audio signal is electronically transferred, the cleaner that signal will be.

If the Crosley is to be placed too far from the computer for an interconnecting cable to be practical, then yeah, generally speaking I've found that with the sound quality of bluetooth devices it's pretty much the same as most other products; ya get what ya pay for......