Legacy audio manufacturers

I'm sure this has been brought up before but does everyone remember some of the older (now legacy) audio component manufacturers? I'm wondering whatever happened to brands such as Nikko, Optimus, Kyocera, Nakamichi, Advent, KLH, AR, etc. My very first official (albeit used) audio system back in the 70s consisted of a monstrous Sherwood receiver, KLH bookshelf speakers and an AR turntable. Thanks.
Teledyne bought AR from Edgar Vilchur, inventer of the acoustic suspension speaker, in the late 70's and introduced the AR9 vertical series. They introduced the 9LS in about '82 for the same price as the original 9 was introduced. Although it received the Grand Prix Award like its predecessor, many believe it marked the beginning of AR's decline which continued into the 90's. Audiovox owns AR now, I believe. AR did come out with an updated turntable in the 80's which I think was fairly well received. But the great AR apparently succumbed slowly from corporate mentality.
Optimus was/is a Radio Shack brand. Nikko made nice inexpensive receivers in the early 70's. Their tuners were excellent. I had a nice Sherwood receiver back in the very early 70's. I remember Stereo Review gave it a glowing review so I just had to have it. I traded a Sansui receiver that I had towards the Sherwood. The Sansui sounded much better.

Advent has been resurrected with different speakers. Remember Bozak? I had a pair of them back in the mid to late 70's. What about Rectilinear speakers? I think they were made in the Bronx in New York. I had a pair of 3a floor standing speakers which I bought off my college roommate for 200.00. When the newer and improved upgraded 7's came out, I stupidly sold the 3a's. That was over 39 years ago and I still regret it to this day.
Hey thanks to Arnettpartners and Stereo5 for their replies and information. Actually after my original KLHs, I purchased a brand new pair of AR17 bookshelf speakers and absolutely loved them. Remember those? I'm sorry I meant to write Optonica and not Optimus. My friend had an Optonica cassette deck with auto-reverse back in the early 80s. We thought that was so advanced !! Yes I do remember Bozak but not Rectilinear. Oh and yes I forgot about Sansui. Great feedback. Keep it coming. Thanks.
Yes, I still have the AR18 bookshelf. I liked KLH too. Henry Kloss partnered with Vilchur at first. He made the cabinets. But then they couldn't get along and he went on his own.
kyocera, the giant ceramics/e made a foray into high-end audio in the 80s and even acquired the post-kloss klh brand. their products were quite expensive and positioned to compete with mcintosh, et.al. i've owned a number of their receivers, cdps and a turntable--all were good and very well built. their separates, in particular, are much sought after and superb.
Oh the memories...Loved the Nakamichi decks, with all of their buttons and of course the auto reverse that spun the tape and not the head...end up buying on a couple of years ago on Clist. Also, Magnovox CD players - thinking back, it actually sounded pretty bad, but hey, it was exciting to spin those shiny silver disks for the first time. Also, remember visiting Fedco and in their audio section thay had Infinity (before Harman), Soundcraftsmen, funny looking Design Acoustics speakers...oh life seemed so easier back then.