I am a beginner piano player who recently purchased a yamaha ypg 635. I love the piano itself, i have only one drawback...i want it to be much louder! I was wondering what is the best way to hook it up to either an amplifier or pa system or even a voco pro karaoke system! Any suggestions or advice will be greatly appreciated! thanks everyone! This is such a great place!

look for a thread about the logitec z-2300.

If it has a line out you can run a cable from that to your stereo or p.a. If not, you can run a cable from the headphone out to the stereo or p.a. I run my privia 120 to my p.a. from the headphone jack. Sounds great. You can get cables and adapters at your local radio shack. Just tell them what kind of jacks you're running from the dp to the p.a./stereo and they'll set you up.

Here is what I just posted on the subject. Piano has a huge range. You want accurate not punchy bass and because yu tend to play mostly a few octaves around middle C. make sure the system does not cross over in that range.
My Sound System

can i run the ypg 635 through a good karaoke system? like a vocopro duet or better?

You can run it through anything that has the inputs to do so, but the quality of tone is going to depend on the quality of the unit you hook it to. I took a look at the Vocopro Duet online. IMHO you'll get better sound from the onboard speakers already present in your dp, but that's your call.

Wujek,

Hi. I am new here as well.
I also have a Yamaha YPG-635, and I run the headphones out to a pair of M-Audio AV40's. You can get these for about $150 for the pair, and they sound GREAT! I don't know what your price range is, but I didn't want to spend more than $200 for speakers for a digital piano that already HAS speakers that I already paid for, heh.
But if this is your price range, you will be seriously challenged to find anything better, unless you buy something used. They are 20 watts apiece. Plenty of nice bass (a definite upgrade from the 635's onboard speakers) and the mids and highs are loud and crisp.) They come with all the wiring you could possibly need, even a cable to hook your mp3 player to auxilary in on the speakers so you can play along with your music. One problem I have noticed though" with headphones plugged in, the sound can still be heard faintly over the speakers. I returned them, and the replacement pair does the same thing. Oh well, I'll deal with it. Cuz it's nice to be able to play along with my mp3 player.
Good luck!