Got a used as-is shruthi and

It has an issue with the filter, Well essentially the filter doesn’t work and audio output come out from the input jack. The person who had it before me said that was the only issue. I was confused as how that could an issue with placing the jacks reversed since it’s soldered directly into the PCB. I didn’t really think much because it was cheap and figured I could fix it.

Now I have it in hand, indeed there is an issue with the voltage. Not sure where to proceed as I’m unfamiliar with where to start on a shruthi. As I check the voltage I get a strange reading of 10.1 on my positive rail and nothing on the negative rail. I’m not sure if I’m taking wrong readings or what as it’s strange someone would continue building it with that reading. I figured it might be the difference between the negative and the positive rail (from -4.9v to 5.1v) would make that seem right but I’m not getting any read on the negative rail. Where should I check first? where should I check voltages?

Have you found the build instructions? There is a detailled guide for checking voltages in there.

Let me look again as I didn’t see it in the build manual. The control board is working perfectly fine it seems. I might just get a different filter board and do it all myself rather than have to trouble shoot this board. I could just strip the board and do it all over too so that way I can trace the work easier.

One of the ICs is in the wrong way round, I think. Check the orientation of all the filter chips.


I need to try that because I saw another thread that talked about that, but everything seems in the right places, dots/indents are all orientated right it seems. I might try and see if something is reversed or the dots are indicating an opposite direction from the indent.

The only time I’ve experienced audio coming out of the input is when I had a chip in the wrong way round. I doubt it could happen for any other reason.

One thing to look out for is you may have had the IC socket soldered in the wrong way round (done this myself), so the chip is orientated correctly according to the notch in the socket, but the socket itself is the wrong way round. Easy to do…


So I couldn’t even with my friends professional help get it working not even replacing any of the dang IC’s and all the things read absolutely fine. I decided to remove the IC sockets. Gonna solder it directly on and see what happens.

If it doesn’t work, I bought a board for an SVF filter, much easier just to fix my issues than fix someone elses mysterious problem.