Need some advice: Found some Audio Equipment

Sorry for what may be an obvious question to some but looking for some help.

I was cleaning up at my parent's house and found some Parasound Home Theater gear. PDD 1550 decoder, PSP 1500 preamp, TDQ50 Tuner and SCAMP power.

Not clear to me if there is any value in these. Would recycle if not but thought I'd consult the experts here first. Any idea on value and where to sell?

Thanks