I hooked a CD player up thru the auxiliary input and it produced sound from both channels. I think the right channel sounded muddy. It also picked up my local fm station. No further testing was done. All the knobs move freely. This unit is 50 years old and is overdue for some TLC. Restore or use for parts. Will be well packed and shipped Fedex with no signature needed. No p.o. boxes, you must have a physical address. Flat rate shipping in lower 48 states only. No returns on this one. Look at the pictures and feel free to ask any questions.