Thanks - that helps a lot.
I've made some measurements with ARTA meanwhile and found that I also have a slight 50Hz mains hum in the phono stage. I suspect that my transformer might be just to close to the phono PCB.
Since I don't have any options to rearrange the components, I am thinking about moving the PSU components to an external box entirely.
I Make the Preamplifier and I Have BoardsIf anybody in India has done a run of these boars Id be interested. In buying them. International shipping is kinda pointless.
Else I plan to get them made by Jlpcb. Ps: You dont need a membership to download the gerber files.