SMR-4 MK1 0.5v problem

Hi gang!

I built a shruthi 2 years ago, and somehow the filter panel doesn’t work today :(. If i use the 4pole, i only hear a midi message “sound”, it works with 2pole, but there’s no resonance.
I’m planning to resolder this thing, but i would check some resistors/connection before. Can you give me some help, where i have to start?
Thank you!


> i only hear a midi message “sound”

What is that? Maybe you can post an audio sample.

I am not sure what you mean by “no resonance” too. Does it mean the “resonance” setting has no effect at all, or that the filter does not self-oscillate? SMR-4 mkI v0.5 is not supposed to self-oscillate in 2-pole mode - but the resonance setting definitely does something to the sound.

Try to find at which point you don’t have sound:

sorry for my bad english, so the “resonance” setting has no effect at all in 2pole, and no sound in 4pole. i will post an audio soon, but its weird because it worked.

I had a similar issue, this was caused by dry solder joints. I suspect that the lead-free solder I used at the time is related to this problem.