From: liz@poppyrecords.invalid.invalid   
      
   Geoff  wrote:   
      
   [...]   
   > Curious as to how a simple mechanical switch (slide ?) could 'introduce   
   > noise'.  Unless close to a powerful electro-magnetic field such as an   
   > external power supply, or close mains cabling.   
      
      
   If there is any DC on the circuit, any change in contact resistance will   
   cause a changing voltage.  "Noisy pots" are often caused by leaking   
   electrolytic capacitors allowing DC onto the resistance element.   
      
   --   
   ~ Liz Tuddenham ~   
   (Remove the ".invalid"s and add ".co.uk" to reply)   
   www.poppyrecords.co.uk   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)