How to use UM66 or BT66 Musical IC

The following schematic is for UM66 or BT66 musical IC. You need very few components to make this circuit.
Pin configuration for UM66 is given below:

Zener diode rated 3.3V maintains the required 3.3V for UM66 IC. The output from Vo of UM66 is amplified by BC547 transistor.

Click on the video to see the output


  1. i am working on doorbell project . i also need loud music.Can you please send me that cirucit diagram .do i need to use same speaker as specified in ckt(wattage,resistance) or is there any substitutuion or that.

  2. i found um3481 is nt being manufactured. is it true…. is there any other ic which can b used instead of [[um3481]]

  3. Hi,my name is Satish. i just got on your site and to my great surprise your site is very good. i mean it is very explicit. it leave nothing to my imagination it’s really a great site for me. i am beginner in this field and i greatly appreciate your site. well can you help me by showing me how to convert a small voltage let say 3-9v into 220v.


  4. can you pleas send me a circuit diagram of melody generator using um66[not this diagram]
    i wanted with a loud music!

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