Noise at end of most patches

Hi - I purchased a Shruthi (classic) already built.
Listening on headphones to several patches there is a noticeable short noise at the end of each sound - almost like a squeeky chair perhaps … hard to describe. It seems to be there for the majority of different synthesis sources and waveforms. No amount of tweaking envelope / filter seems to remove it.

Could the moderator allow me to upload a short recording of it?

Thanks.

Link to Wav file

Above is a page with the sound (don’t leave any comment on this page! :wink:)