It may be as simple as either a defective or cheap volume control
potentiometer. The give away is it happens near the "zero mark". As
the wiper approaches on end of the travel, it rides up off of the
resistance element and onto the metallic end connector. This can
momentarily cause the wiper to go "open" and cause the spike you hear.
You can try another pot or you can place a resistor that is 10X
bigger than the pot resistance from wiper to the "zero" end terminal.
This way the wiper cannot go "open". This may lessen or eliminate the
--- In Electronics_101@y..., "obin69" <beaty40@h...> wrote:
> I am using a stereo preamp that has the TDA1524A chip to control
> tone and volume. It is coupled to two 18w BTL amps.
> When the volume control is turned down to near the zero mark I get
> occasional hefty spike through the speakers. It is not a
> Is this likely to be the fault of the chip or should I be looking
> another reason?
> Peter Wright