Cartridge/tonearm shaking and other questions


Forgive me, I wasn’t sure how to capture my questions in the title of thread but I hope I can explain my issues and get some advice. I also think my questions are general in nature, regardless of the model and someone has probably run into these before. The first issue I have is when I turn the volume up very high, even with the tonearm at rest, if I tap on the tonearm I can hear the tapping noise from the speakers. I checked the ground wire and it is tightly connected to the preamp. The second issue which may be related is sometimes, as the record is being played, the cartridge assembly starts to vibrate even with the volume completely turned down. This happens on records that are completely flat and clean and can get bad enough to cause momentary skips and then calms down and all is well. I have owned several turntables in the past but have never run into the vibrating cartridge scenario before. The tonearm noise I just happened to notice when I was moving the tonearm to the next track with the volume real high otherwise I would have missed it. Thanks in advance.

P.S. I should add this is all related to a new (to me) turntable I recently picked up and covered in a different thread.

128x128kalali
@kalali,
The first issue I have is when I turn the volume up very high, even with the tonearm at rest, if I tap on the tonearm I can hear the tapping noise from the speakers. I checked the ground wire and it is tightly connected to the preamp.
https://forum.audiogon.com/discussions/tonearm-microphonics

The second issue which may be related is sometimes, as the record is being played, the cartridge assembly starts to vibrate even with the volume completely turned down. This happens on records that are completely flat and clean and can get bad enough to cause momentary skips and then calms down and all is well.
What cartridge, tonearm and turntable caused the problem?

The turntable is nothing special but it appears to be very rarely used. It’s a Technics direct drive SL-3300 from the 80's with the standard S-shaped tonearm and an Audio Technica AT95E cartridge. I'm considering to upgrade the cartridge but want to rule out major issues before doing so.
imhififan, thanks for the link. Excellent information about my first question/concern. Some of the posts also refer to some resonance issues which seems to be consistent with the behavior I see. The "shaking" I mentioned appears to be caused by the cartridge vibrating at its natural frequency. Still don’t understand what is causing it. I have the turntable sitting on top of the preamplifier and I’m now wondering if that’s what’s causing the resonance.
The HI-FI News test record has a resonance test. Playing the track causes the head to wag at the resonant frequency which should be 8-15 Hz.  Damping, worn suspension and cartridge/arm mismatch are some possible causes.  
Dear @kalali: In reality you have only one " trouble " because the first one is just normal. The second one means that the tonearm/cartridge combination you have are not a good match and sometimes its resonance frequwency coincide with frequency resonance in the LP and then vibrates. Other reason for that could be that the cartridge/tonearm parameters set up is not accurated or that the stylus tip or cartridge suspension are in bad condition and with some high velocity recorded grooves happens what you experienced.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.
Thank you all. I isolated the turntable from the preamplifier by mounting it on a large - 13"x13", ceramic tile sitting on four damping blocks and played several LPs and I think I managed to eliminate the resonance. I'm guessing something in the preamplifier, perhaps the transformer, was causing the tonearm/cartridge to resonate. Didn't have this issue with my previous turntable I suppose because that combination had a different mass. I'm looking at some rack options to have a more elegant solution to address this issue. I have rarely listened to this system in the past few years but I'm warming up to the analog sound again after a very long hiatus. Another rabbit hole to follow....