Hi Ralph,
Welcome to the forum and hope you'll find a lot of enjoyment reliving the past.
Also, I did want to point out a few things....
sailordude wrote:
I'd like a list of machines because I'd like to upgrade from this model which doesn't have an S video connector.
Since LD is a composite video format, S-Video is an irrelevant requirement for better picture quality (in fact it's worse in most cases). You will always get better results w/ the composite output and utilizing a TV or video processor w/ a good 3D comb filter. Also, trying to find a TV in this day and age that still sports an S-Video input is almost next to impossible.
As for better machines, you probably already know what was good since you sold players back in the day. However, if you need a refresher, you should probably focus on players that incorporate "digital field memory" (the giveaway is that they usually incorporate a jog/shuttle dial) not only because they can manipulate special effects playback on CLV discs but are just simply better performers in general for picture and sound.
sailordude wrote:
I remember selling a Denon LD/CD changer at one time and I am interested in something like that if anyone is familiar with them.
I'm certain Denon has never made such a machine since the only known design of a CD Changer w/ LD playback capability is the M series of which you already own. In fact, Denon has never made an LD player on their own as they are all clones from either Philips, Pioneer, or Panasonic. So basically, you are no worse just keeping what you have as there no better equivalent available.