Troubleshoot'n time!

Just finished building my first Mutable – a Shruthi with SMR4. (yippee!) Man, I am so impressed with the quality of these kits – the design, engineering, instructions and quality are all amazing.

Everything looks good with my build that I can see: all the pots, buttons and display do what they’re supposed to. But I get only the faintest signal from “audio out” – hidden behind static when I have the gain on my amp turned to max. However, I do get reasonable signal with the amp plugged into “audio in.” I searched and found some other posts with similar issues and I will follow the advice to try the audio tracing described in the trouble shooting section of the build instructions. But I thought I’d also see if anyone has had the same issue and found the “smoking gun” (I see some examples of the same symptom but none that say what the problem was…)

Cheers, and thanks in advance!


It can be anything, really, so please trace the signal on the filter board.

Most obvious thing to check for is that you have the link wire by the output socket, you have to either use a pot or a link wire.

Then check the soldering on the output port.

If still no good you have to trace the audio through all the stages of the filter board.

Fixed! The audio tracing did the trick – found two problems. One of the ICs was not pressed completely into the socket and two of the pins on the “2 pole or 4 pole” jumper were not soldered. (Seems that the guy who assembled this one was a little too eager to get going…)

Now the to-do list looks like:

1) tune the filter
2) post to “completed builds” forum
3) eat victory candy!
4) hours of learning how to make noises :slight_smile: