Sorry to revive an older thread, but I like to throw in that I have been an owner of an Akai AS-980 for a few years now and a few of my experiences for anyone who is slightly interested in this little known receiver.
I bought on Ebay a few years back for ~$100 (that includes shipping) as non-working and as-is. I was looking for a good receiver that I could connect a bunch of stuff to without having to by a bunch of decoders and other things. The Akai seemed to be it so I took the risk. It was well worth it. It turned out all it was was some dirty fuse connectors on the back. Some buttons are still dirty which kind of stinks. I really don't want to rip this apart to clean the knobs since it works so well. Also, watch out for the proprietary speaker plugs on the back. Luckily, Pioneer still sells them (or did sell them back in 2008.)
I love the receiver. I've been through quite a few receivers, both stereo and quad, but the Akai has always come out on top. Its always sounded very, very warm even compared to my good, old SX-3800. Its a pleasure to listen to anything from classical to techno/pop music. I always run it with the loudness on (don't we all?) but at that point, everything is perfect. No need to mess with any other tone controls. Plenty of power. I can crank it up till my ears hurt and the walls resonate through all four speakers and still no distortion. I still haven't encountered any distortion. I need a much bigger room to put it in...
The lights started to go on me so I replaced all of them (except for the meter lights) with LEDs. The front panel doesn't run so hot anymore. While doing that, I accidentally shorted out the rectifier circuit for the meters, but luckily Akai seemed to place everything so that it is decently accessible and I fixed it with Radio Shack parts. Plenty of wires inside and looks quite intimidating, but unless you want to remove all the knobs from the front panel, everything is positioned quite well for service.
The matrix setting on it is amazing IMO. I'm not a pro on quad decoders like some people on here, but compared to other receivers I've tried, I have never heard such discrete sounds out of stereo material. My Dolby Surround doesn't even sound so discrete (Its just that artificial delay that makes it sound like it is!) SQ decoding is decent...I suppose... Front left/right information and rear left/right information always seem to blend into the sides, but I think that is how it is on basically every non-Tate device.
CD-4 works well. I have a few problems with channel separation, but that is probably because I'm using a Grado turntable cartridge that is non-Shibata and a turntable that doesn't seem to have flattest azimuth in the world. I've heard though that it works really well though if properly set up (I'm planning on doing that as soon as I have the money to buy a linear tracking turntable and Shibata stylus.) The FM section is quite strong especially after some tweaking. The AM reception seems to have some sort of muting feature that is pretty cool; It seems to squelch frequencies without a station. None of my other (non-digital) receivers do that...
So I use the AS-980 as my main receiver. I route all my music, TV shows, and usually movies through it and have never once thought twice about it. The fact that one has four full range speakers connected basically solves the lack of a subwoofer. All in all, the AS-980 is a great purchase as quad/stereo unit for a starter or obsessive quaddie. I'm sure the AS-1080db is similar.