This is sort of a baby pioneer, rescued from the scrap bin. It came in with a couple of bent knobs, and an amp fault which showed up later. The pot shafts were heated with a soldering iron and bent back, and the whole front given a bit of a clean.
There was a dodgy transister in the feedback circuit which varied when you touched it - so easy to identify! After a bit of detective work I put in a new pnp of suitable voltage - but with a bit less gain. This made the channel louder - so I changed the other side too. Replacing a couple of electrolytics with tantalums completed the fix - all the panel lamps were fine anyway. Funnily it sounds better than the sx-838, which is cool..