Will you accept old stereo receivers and/or guitar amplifiers (amp 'head')? (Actually, some still working)

Yes they will take those items, they are considered E-Waste. Even if the device still works, it won't be reused again only recycled. Here's a link (scroll to the bottom) of what they take: http://www.oclandfills.com/hazardous

Why not Craigslist the working units or donate to Salvation Army, Goodwill or? Salvation Army may even come to pick them up so you don't have to trek them out. You can label the non-working ones - one man's junk being another man's treasure! Here's the link for the SA truck service: https://satruck.org/?pid=cpc:arc_grants::google:::::western_western:arc_brand:salvation_army_brand:brand&utm_source=google&utm_medium=cpc=arc_grants&utm_content=western_western&utm_term=salvation_army_brand