The first synthesizer i owned was a Yamaha DX21. At that time there was no  internet site for this series of synthesizers. So i made one. Lots of people did find this site.

Now i don't have the Yamaha DX21 anymore and also i don't have any time left to keep the site up to date.

So i decided to skip the site. Al the information (and more!) can be find on a new site:  Yamaha 4OP synthesizers site. For more information you can also go the the Yahoo DX group.