Hello Chas

On 01.05.18 01:43 , Chas D 350ypvs@... [kiwitechnics] wrote: You can rule out a digital to analogue converter

Though I think, that the OP has different problem: That is not true. The D/A-converter provides everything for the sound control. For example the envelope for the VCA. If the D/A is broken, then there is no envelope or gate for the VCA and so there would be no sound.

Florian