Everything works perfect except SMR-4 filter


I finished assembling quite while ago

Everything works except SMR-filter.
Cutoff and Reso doesn’t work.
I have tested what pichenettes suggested on topic"SMR-4 Filter Board - no sound only “click” when note on".

No.1 to 8 sounds same as No.1as original sound from shrunthi-1.no filtered sound.
might be no.7 is a little bit quitter and No.8 is a little bit louder.

I guess that’s because of my poor soldering but It would be fantastic to know which section is problem.


Which voltage do you get at the frequency and Q CV pins?

I feel very shame on me but
the frequency and Q CV pins shows all almost 0v.

So even if you change cutoff and resonance on the digital board the Q and cutoff pins stay at 0? Are you checking them on the filter or on the digital board?


I was checking them on the filter board.
Frequency shows 0v to 2.45v
Resonance shows 0v to 4.88v

Cvpins shows 0. Should I move something to check?

You don’t need to care about CV pins. What’s the voltage at pin 1 ofIC3 when you sweep cutoff?

On which position the pole selector is set?

the voltage at pin 1 ofIC3 is 469mV to -425mV

I checked Frequency again and shows 0.5v to 4.97v