I have been swopping cartridges around as I have built two Phono2s for the bake-off, one MM one MC. I was testing the MM one first with the SPU, full volume no noise unless ear to speaker. So I swapped the headshells to the M3D one and it is noisy as hell, it sounds like a valve MC stage

. Now it wasn't noisy the last time I listen to it a few days ago, so I swapped it out for an Audio Technica AT52E and that was silent, so it is a bit of a mystery at the moment. I am sure there is a simple explanation when I get time to look for it.
The stage speced out OK on test, just a couple of mv dc on the output. The input is direct coupled to the first gain stage which is just there really to provide the headroom and that is also where the gain of the unit is set, the RIAA is hung around the second stage.