Re: Commodore PET Speaker
The attached is lopped from the PDF instructions for the Kitronik Mono Amplifier V3. it shows that the feedback resistor R2 largely controls the gain (amplification) of the amplifier IC.
Try changing R2 to 220K or 470K, but first, please do measure the size of the signal coming out of the 'M' output and make sure that it is at the expected logic 0 / logic 1 levels - when the port is actually producing sound, of course.
|