I’ve heard people complain about how Gryphon use “cheap” hard plastic feet for their amps. But my experience above makes me think this is very intentional.
Gryphon sells coupling spikes for their gear (stupidly expensive of course) but they clearly state they won’t help when used on their heavier gear like amps.
Still can’t get over how much of a negative impact the vibration control made with the amp. It was a massive change that anyone could hear. I think when I added the vibration control to the amp it was late at night and I didn’t immediately check for any difference in sound after installing. After all, I had previously installed Herbie’s Tenderfoots under the rest of my components with great success in improving sound, so I expected no less when using them on my amp. And while it obviously caused issues for a few months I chalked it up to me having become more intimately familiar with my system including weaknesses.
Later I’m going to try adding only the Herbie’s feet under my amp’s feet, to see if they are the culprit or if it was adding the Butcher’s Block as well that caused the issue.