K553UD1A is one of the first Soviet integrated operational amplifiers. This one is manufactured in June 1978.
![]()
It is a functional analog of µa709, though, it is not it's per-layer copy:
![]()
Image from diyaudio.com.
It is a functional analog of µa709, though, it is not it's per-layer copy:
Image from diyaudio.com.