Doing a bit more research particularly at other Pioneer units, of different vintage, it's apparent the ACH acronym does not reflect the material its constructed. Lots of electrolytic capacitor in the circuits of different models are labeled ACH, so my conclusions are completely wrong. Sorry about that. 😳
The only mystery is just that is larger than normal. But clearly, it's an electrolytic polarized capacitor. I was so focused on this unit I lost track of the forest.
The only mystery is just that is larger than normal. But clearly, it's an electrolytic polarized capacitor. I was so focused on this unit I lost track of the forest.