Help needed for UNVERIFIED AS3340 VCO Stripboard Layout (No Arduino/Display)

DIY STUFF
27

A couple things I can think of to try:

  • Measure the voltage on 3340 pin 5. That’s the pulse width control voltage and it should change when you move the PW knob. What value(s) do you see?

  • Do you have an audio probe? You could use that to try checking the signal at 3340 pin 4 and comparing the level there to TL072 pins 1 and 3, it should be the same in all three places. If it’s louder on 3340 pin 4 and TL072 pin 3 then there’s a problem at the op amp.

3 Likes