Shruthi output level drops randomly

hi all,

if been using the shruthi (smr4 mk2 filterboard) for a few years now. its been a great toy! one day i plugged reverse power and the +/- voltage changing chip and optocoupler blew. i was able to change the chips and everything was workin fine again. until now…
recently i started to have the following problem:

after a random amount of time the output voltage drops to aprox one third. when i reconnect power everything is fine immediately. do you guys think this is linked to my incident? has anybody seen something like this before?


I’ve never seen anything like this before. It’s quite strange that it resets itself immediately after a power cycle… Which MIDI device do you use to control/sequence the Shruthi?

I’d check the soldered joints on the output socket and generally across the audio path. I had similar on a PreenFM I built and reflowing solder helped.

Are you sending MIDI Volume messages (CC10, I think) to it, without realising it?
Does the Shruthi-1 respond to those, I wonder?


toneburst: that’s exactly why I asked about the MIDI device. And this is compatible with the volume getting back to normal right after a power cycle!

It’s MIDI CC7 for volume, 10 is panning.

Oops, sorry, all…


thanks all,
i pretty shure the controller is not sending midi. but im gonna make some tests these days. i let you know