Is it safe to chmod 777
 

Is it safe to chmod 777 /dev/dsp /dev/snd /dev/mixer ... on a single slackware box?
To listen to java based web sites?

Are you allowing remote users to connect to the computer? Are you worried about the people who have physical access to the computer trying something stupid?

If no, then yeah, it's safe to chmod to 777. But I do have to ask why you need to... do you have choppy sound playback? If so, try switching to OSS for sound before changing the permissions.

No to all of thee above. Im jus trying to get sound frem java base web sites like say pogo.com. To here sound thats all.

Before taking that leap, I'd suggest you try it with something like an MP3. If you don't get sound playing an MP3 on your desktop, you won't get sound on the website, no matter how hard you try.

When you've got sound working on your desktop, then you shouldn't have to change anything for the websites.

Out of curiosity, what sound card do you have?

Better is to add your user in the audio group