Not sure how to start my own thread on this since I'm new here.
You just did
![Beaming face with smiling eyes :grin: 😁](https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f601.png)
https://groupdiy.com/threads/se-electronics.70694/
The I and II look identical to me, apart from the added switchable pad & high-pass, so the PSUs should be interchangeable indeed.