My Kurzweil K250 keyboard is still playing great after all of these years, but has developed output static while playing music (not at idle). It is not all the time, and sounds like capacitative discharge. Some days it is worse than others.
My immediate thought is some type of filter capacitor, likely in the power supply, which is in a separate pedal pod. Secondly, it may be on the audio board. The static is present in all channels and headphones.
Might anyone be able to offer any thoughts on this? I love this keyboard, use it all the time, and it still has FANTASTIC sounds for its age. Please advise, and thank you!
Does changing the output volume affect the scratchiness at all? It’s not uncommon for a bad volume pot to cause this (though it could certainly be something else). That said, when people describe the sound as “scratchy” my first thought is to open it up, strategically place some paper towels, and then repeatedly hose down the volume pot with this https://www.amazon.com/dp/B00AF0OFVU or similar.
Another thing to look at would be to clean the outputs with some industrial alcohol (99%). You could risk 91% as long as you have a fan set up to dry them out completely.
Thanks - this is a possibility, although it seems to be happening at all volume levels. It is possible the slider pot is dirty, since this instrument has been around since 1984.
When I get time, I’ll give it a try and see what happens. This is a good start, rather than to break out the soldering iron right off the start.
If the volume pot doesn’t seem to affect it, I would try cleaning the outputs with alcohol first. If you use 91%, finish it off with a hairdryer to get rid of all moisture. Bottles of industrial alcohol are around $20 on Amazon. I would think it odd the volume pot makes the sound distorted if moving the volume pot has no effect on the scratchiness, but stranger things have happened.