From: soahmz@gmail.com   
      
   On Sunday, January 15, 2023 at 6:07:33 PM UTC-8, Joe Jaramillo wrote:   
   > On Sunday, September 25, 2022 at 11:23:12 AM UTC-7, Joe Jaramillo wrote:    
   > > I have the same problem on a C 430. I’ll be playing either quiet or loud   
   and then a hear A rumbling noise that kind of trails off for a bit and then   
   comes back. Did you ever find out what the root cause was?    
   > > On Wednesday, March 12, 2003 at 9:56:01 AM UTC-8, Michael and Janet Inman   
   wrote:    
   > > > I have a Yamaha CLP-411 Clavinova that is about five years old. It has    
   > > > developed an occasional rumbling sound that comes from both speakers.    
   > > > It only lasts a few seconds at a time, is unbelievable loud, very low in    
   > > > pitch, and sounds just like wind noise on a microphone. Seems to happen   
   at    
   > > > random times although more common when someone is playing it. Volume    
   > > > control position has no effect on the noise volume but does sometimes   
   seem    
   > > > to affect the timbre of the noise. It goes away when you plug headphones   
   in    
   > > > (you don't hear it in the headphones).    
   > > > Without the benefit of a service manual/schematic, I have tried to trace   
   the    
   > > > analog audio signal with an oscilloscope to at least determine from   
   which    
   > > > stage the noise is coming. I'm suspecting it's originating in the power   
   amp    
   > > > section - the amps are IC "bricks", one for each channel but since it's   
   in    
   > > > both speakers equally I'm thinking it's not them. Due to the sheer   
   volume    
   > > > of the noise it actually loads the power supply to a point where signals   
   at    
   > > > all stages are affected. I did change the filter cap in the dc supply.   
   No    
   > > > improvement.    
   > > > I did read some newsgroup accounts of noise in the Clavinovas being due   
   to    
   > > > dirty contacts in the volume control... I'm picking up some contact   
   cleaner    
   > > > today and will try that but I'm not too optimistic about it.    
   > > > Any experience with this problem or guidance much appreciated.    
   > > > Mike   
   > Incidentally it also happens with headphones so I’m a bit flummoxed. Oh   
   and btw I have a CLP-440. Next stop Yamaha…   
   Oh damn my church piano developed this issue too a few months ago, and it's   
   been driving me crazy!   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)