I've been reading much of the emails, but this is my first time posting a reply. Let me first say "Hi" to everyone and thanks for all the great information, including the help you've given me in selecting the PSR2000. It's a perfect addition to my setup.

Regarding the "hissing sound". I've been spending a lot of time trying to minimize it. I've spoken with Yamaha support and worked with experienced people from the store I bought it from. Some of the comments in the emails were right on. Let me give you my opinion based on what I have learned.

The hiss is produced only when the mic input is used. The hissing sound is most noticeable immediately after saying something into the MIC, especially when the volume is turned up. This happens when
using the main speakers, the headphones, or the line outs. When the MIC is off, there is no hiss at all while playing the keyboard.

I've tried changing between low impedance and high impedance MICs (one of the MICs I use is an SM58). Not much affect. I also thought it could have just been a problem with my specific keyboard, but we were able to duplicate the same exact thing with the model in the store.

I believe this hiss is related to the noise-gate. When the noise-gate is on, it suppresses any noise from the MIC input by simply switching it off. It automatically switches it on when it senses a threshold has been hit at the input of the MIC. Note that this threshold is programmable (MIC SETTING page). For those who mentioned that they have a constant hiss, it could be because they have the noise gate turned off.

I believe what's happening is that when the noise-gate senses you speaking into the MIC, the voice signal is let through along with any accompanying noise from that input or the internal A/D circuitry. When you stop speaking into the MIC, the noise-gate eventually switches off, and the sound is perfectly clean again. However, I believe there is a lag in the detection of the signal going away, and this is causing the noise (or hiss) to stay on for a short time after you stop speaking. (This is my guess...I really don't have enough knowledge of the circuitry).

I have not found the programmable threshold to help much with the hiss. The only true way I have found to minimize the hiss, is exactly what was suggested in previous replies...lower the high-end filter. Through experimenting, I have found that the best setting is 8KHz with -5dB attentuation for the EQ HIGH (I think the factory settings were at 16KHz). You can do this on the MIC SETTING page. Note that you can completely eliminate the hiss by fully attenuating the highs, but your voice won't sound too good. I've found this setting to be the best compromise. You'll have to find your personal favorite.

If anyone's figured out a better setting, or any other techniques to minimize the hiss, I would love to hear it. Yamaha told me they were not receiving any complaints about this hiss, so they were not able to offer much help to me. They did not validate or deny my theory of the "hiss lag".

It's interesting to note that the overall noise suppression for this instrument is really pretty good. It's just that when the noise-gate is on, it's perfect, so it makes the noise so noticeable when it switches off. It would be ideal to have that all the time....but too much to ask for in this price range.

Of course, when playing full songs with accompaniment, it's hard to notice
the hiss. But, when playing piano songs like "Desperado" and using the MIC
for vocals, it's very noticeable.

I hope this helps.

-Thanks, Kevin