Hi Nico,
I'm trying to follow the progression of this thread after becoming aware of its existence from a friend. Are you interested in possible solutions or are you just wanting someone to report back on their findings listening at 100-105dB (peaks?) or both?
If you are looking for possible solutions, can you provide a bit more information? Here are a few practical question I'd ask:
- For a practical application test scenario, can you list a couple of rock LPs (hopefully something I have in my archive) and track titles where you have experienced this issue so I can attempt to duplicate?
- Can you explain the type vibrations you are talking about (This would be something like: a type of feedback that overloads the system and creates severe distortion or something else explained in a similar manor.)
- Can you share the condition (or scenario) of one or more of your LPs where, within the music's performance, this occurs. (for example: 2:34 into LP xx track title xx, the vibrational feedback occurs, etc.)
- If you listen to the same music at the same level setting on your preamp and you turn your subwoofers off, do you still get the same condition? (I'm not suggesting you stop using your sub. It's just a test case that could help provide additional information to help with identifying the effect under a different condition.)
- Are you on a concrete or suspended floor?
- What type of support (equipment rack, platforms, feet, etc.) do you have for your turntable?
- Does your phonostage contain vacuum tubes?
If you'd like to, or prefer to, discuss this offline, we can arrange that. We have a mutual friend that once lived in R. Va. when we first met many years ago. If your contact info hasn't changed, it is available to me. If it has changed, you can contact AC and ask him to send you my contact info.
Dre