Polivoks problem

I (finally!) finished building my polivoks.
I can send midi notes to it, but the sound I get sounds strange. E.g. as soon as I press the filter page/button 2 the sound gets louder and I hear a low noise sound. On each page I hear a different distortion, noise and/or loudness. However I can hear the played melody.I checked all solder points with a lens, but couldn’t find any problems.
I currently don’t have a multimeter to check things (because my dad lost it :D). However maybe someone has an idea.

Filter board setting correctly set to “pvk”?

Ah I can’t set it, because I still didn’t add the display. I wanted to check everything before adding the display. Could this be the problem? I will try it :slight_smile:

Yes it is the cause of the problem. You’re feeding the the filter mode selection shift register with the bits from the 8 LEDs - so every time the LED pattern changes… random garbage written to the filter mode selector mux!

You were of course right :slight_smile: it works. - I have been wondering, my soldering isn’t that bad :smiley:
It sounds awesome!

I’m missing 4,7u capacitors for my other Shruthi-1s. Are they from Reichelt working? 4,7u 35Volt. And what spacers do I need? I can’t find mine :confused:

You need bipolars here.