I searched and didn’t see a thread dedicated to BHK Preamp modding.
The BHK Preamp has heat vents. While I was replacing the legs one day, I scrapped the vents and heard a zing. I figure it’s not a good thing when a resonant sound hits it, and it begins playing tunes.
So, my first BHK Preamp mod is… lining the vents with padded tape. The bottom side also rings and has tape applied.
Edit: I used this felt tape, though any tape of reasonable thickness should act as a damper.