Since there are settings on the CP4 Stage that can make it sound exactly like an old, out-of-tune piano, it probably is not broken. Unlikely it "breaks" out into this completely on its own, impossible actually. More likely when it breaks it would give you no sound at all.

How well do you know the CP4 Stage?
I ask because when you notice that it has "suddenly changed" what buttons are lit.
Did you perhaps, inadvertently hit an Effects button?
On a scale of 1 to 10, how would you rank your playing style... Where "1" is never break a sweat or a fingernail and "10" being blood, sweat and tears on the keys?

It's a serious question, because perhaps you should be using the PANEL LOCK feature (described in your Reference Manual page 47) this prevent aggressive players from hitting and changing functions by accident.

Let us know.

Hi Bradley,

I have had exactly the same thing happen to me, but it was definitely user error, as I'd moved the pitch wheel by accident... A quick soft reset got rid of the problem.

Mark

I have been having the same problem on my CP-4, which is less than one-year-old. It is not user error. I am not pushing any buttons, or navigating anywhere near the buttons when it changes. Please help!

Tim wrote:

I have been having the same problem on my CP-4, which is less than one-year-old. It is not user error. I am not pushing any buttons, or navigating anywhere near the buttons when it changes. Please help!

The response would be pretty much the same... to eliminate the possibility of it being hitting a button by mistake, activate the PANEL LOCK. If it occurs while the Panel is locked, then you can seek to have that issue addressed.

We have the same problem. This is not user error because the sound still changes with the panel lock on. We use this for church service and the sound will change multiple times in a 1/2 hour period. Is anyone willing to consider that this is more than user error and potentially help us solve the problem? We have an S90xs that is only a couple of years old. This has been happening for some time and it’s very distracting and frustrating. It happens with multiple users/players and happens randomly, but universally.

Lacey wrote:

We have the same problem. This is not user error because the sound still changes with the panel lock on. We use this for church service and the sound will change multiple times in a 1/2 hour period. Is anyone willing to consider that this is more than user error and potentially help us solve the problem? We have an S90xs that is only a couple of years old. This has been happening for some time and it’s very distracting and frustrating. It happens with multiple users/players and happens randomly, but universally.

Lacey, Respectfully, you do not have the same issue as you have a S90 XS, not a CP4 Stage as the original poster. And while we understand your thinking about the [PANEL LOCK] being a similar function, the layout of the front panel of the CP4 Stage and the S90 XS are extremely different.

But here is some good news, you don’t have to convince us that it is not user error, you can have the instrument checked. You can find the nearest authorized Service Center by going to your regional Yamaha website and searching for the Service Locator... for example, if you are here in the USA you would search for help here:

https://usa.yamaha.com/support/index.html

If you are not in the USA, please visit your regional Yamaha website... they will likely have a search function that is somewhat similar, based on the part of the world you are located in.

Hello.

I am having the same issue as the original post from Bradley described. I have a CP4 Stage that randomly changed to a strange, digitized sound twice the other day during a worship set at my church. Thankfully the performance was recorded on video, so you can hear the change and clearly see that my hands were nowhere near any buttons, nor was the pitch bend touched (the mix isn't great, but good enough to hear the change in sound).

Any suggestions on how to fix this to ensure it doesn't happen again. It was extremely distracting and challenging to navigate.

The first time it happens is around the 12:13 mark, and you can see me looking down around 12:22 trying to figure out what happened. I eventually got to a place where I could mess with the effects buttons to make sure it wasn't a setting there (14:45), and eventually had to restart the keyboard to reset the sound. Then you can hear it happen again around the 40:00 mark, and this time I was eventually able to fix the sound by changing back and forth between different grand piano sounds (around 42:15). https://youtu.be/byy8Bfw0jwc

Ideas?

Poor CP4 got scared, I definitely wouldn‘t rule out that possibility....;)

I had this problem on my CP4 once, then realised I had moved the mod wheel slightly with an iPad stand. Easily fixed by turning off the routing of that performance.

I just checked the video, what could be happening is that the mod wheel is not set to fully off when the performance is changed. At some point the somewhat vigorous playing jogs it slightly and sends a new CC message to the sound. If the wheel is fully off, the message will be zero, if it's slightly rotated the message could be enough to change it significantly. It's little difficult for me to hear the change of sound but it appears that the mod wheel is not in the fully off position in the video. Hope this helps.