Can anybody tell me what type capacitor isthis?Is it polyproplyne ,polyester or ceramic? Is it good for audio coupling?

 

Uncoated polyester, like this:
https://pdf1.alldatasheet.com/datasheet-pdf/view/169762/SIEMENS/B32563-J3684-J.html
I think I have also seen uncoated polystyrene and uncoated polycarbonate that look the same.
All of them would be good for audio: polystyrene best, then polycarbonate, then polyester.

 

Thank you for your reply.

 

Thank you for your reply.

The rest of you amplifier would need to be damned good before you'd hear any difference!

 

Noted,thank you again for your information .