#3221
LectronFan
Moderator

    Hi Michael,

    The first capacitor of 10uF is needed to separate the DC voltage of about 0,6V at the base of the first transistor and the input circuitry.

    Without this capacitor, a voltage of 0,6V will flow into your smartphone or tablet 😯

    You could also use a 0,1uF capacitor, but the amplified sound will be thinner, due to it’s value. It will then only pass the higher frequencies.

    This is a good circuit to test your new oscilloscope 🙂 . I also have a well functioning Rigol scope which I used here to make measurements.

    Greetings

    • This reply was modified 3 years, 6 months ago by Michael.
    • This reply was modified 3 years, 6 months ago by Michael. Reason: Changed font and size styling for easier reading