I recently acquired a working 1940's radio and love the sound (for those interested this one https://www.radiomuseum.org/r/general_el_j105.html). It has an RCA input that works. I've connected my amplifier (a Rotel RX-1050) to it using an RCA y-connector and which works well for mono sources however it appears to work a lot less well for stereo sources - the mix often seems oddly unbalanced.
Any suggestions on products that do a good job of stereo to mono conversion?
I've found a few online but I've no idea of their quality.
Thanks!
mark