New built Shruthi nearly right but a problem

Hi People. I’ve just built my Shruthi and, although most stuff works, there is a problem. The output level is very low (volume) and there is clicking sound when I move the pots. Have checked for dry joints and pretty sure the components are all where they need to be. Thinking it might be my psu, though the power ratings on it are right. Before I buy another psu, has anyone got any suggestions for where I should be looking for the problem?

Have you done the voltage checks on the filter board?

Tried tracing the signal?

Yes, they were all fine. Within the correct tolerance

What type of filterboard shruthi is it? Can you make pictures of both boards both sides?

Hi again. Apologies for the delay in getting back (I’ve been away). The filter board is the latest SMR4 mkII. I’ll put some pictures up soon but I did have an issue with one of the ICs - my kit was missing the IC mount, so I direct soldered the IC to the board (very carefully). It’s the one marked on the board OK1, next to the midi connectors (an IC 6N137). A friend said it sounded like there was a problem with the amplifier stage/OP amp. Would this IC explain that? If so, how can I test it? I know there will be a problem replacing it if it is that, as I’ve already soldered the display to the board.
Any ideas very welcome.

The 6N137 is responsible for MIDI interfacing. If the synth receives MIDI (note icon in the top left corner of the screen), this chip is OK.

Could you please post photos of your boards?

OK. Thanks. Will get photos uploaded tomorrow.

Hi again. Here are the pics of my two boards. Not pristine soldering, but have inspected with a magnifying glass and it generally seems OK.
Thanks again.

You need to add bridges near the input/output gain pads:

Welcome to the club, I made that mistake once as well… :slight_smile:

Great spot. Like I said - a newby build :slight_smile: Will add them tomorrow and let you know how it works out. Thanks again.

Thanks pichenettes - all good now. Saved me a lot of hassle there.

It’s a great synth! Now for some fun:)