The AH718 & 719 were the successors, in early 80's, to the famous Hi Q International and Hi Fi International stereo receivers introduced in mid '70s. The Hi fi International receiver actually had FM Stereo decoder, way ahead of its time. Stereo decoders were dropped in the above AH 718/719. Very decent sound when matched with the appropriate speakers.
I have not heard the AH 824, but it was slightly more powerful than AH 718. This was the golden era of Philips, with turntables like GA 242 and F7213. Even their ceramic cartridge turntables and combos sold in lacs of numbers.