VPI Rim Drive vibrations


I have VPI SSM with RIM drive and SDS. The issue I'm having is a vibration being transferred from rim to the desk/platter. As the result tonarm wobbles a little bit in azimuth plane.
I tried to replace the brownish rim belt, change contact force/distance between the drive and the platter, and reinstall the belt - the vibration still there (exactly one wobble per rim's full revolution - 360 degrees).

The speed stability is very good though - have checked it with KAB Speed Strobe.

Any ideas how to resolve the issue?

Thanks a lot!
krell303

Showing 3 responses by mmerlionus

2014 Oct update - Thank you everyone in this thread helping me to resolve the HRX vibration issue caused by the Rim motor drive pushing against the 30 lbs HRX Super platter. As my components improved, the noise from the vibration became extremely intrusive to the music on the LPs. I contacted Dan at Eden Sound with his TerrCone footers on both the Rim Motor drive and the HRX turntable footers. And it works getting rid of the vibration! Unbelievable!

The improvement in the sound is quite spectacular; the clarity is pure like electrostatic speakers. There is no smearing in any frequency of the sound. My suffering over the years from the wobbly footers on the HRX and the motor rim drive is over. The rumbling of the rim drive that impacted the groove of my LPs are eliminated, and I have no idea the music is so much richer and fuller. The highs are skywards and the lows are reaching the subterranean deep. The mid bass is agile with speed; and surrounded with bloom of air. All these gain from the Eden Sound TerraCones is astounding.

No doubt the noise level has dropped tremendously from the chatter caused by the vibration from the rim drive pushing the heavy HRX Supper platter. All the energy has transferred from the shaking motor rim drive using the cheap rubber flimsy footers on the original motor drive. I have no idea how poor the HRX footers are until I replaced them with the new Eden Sound TerraCones. I am amazed when I turn on the motor drive now; I got no vibration from the new TerraCones. Even at 45-rpm. In the old days the 45-rpm spinning is such a pulsating rumba dance. I touch the motor drive with my fingers now with the TerraCones, and hardly any sensation. I actually jump for joy when I first touch the motor unit running as I felt almost nothing; Wow!

Now I find the details from the LPs uncovering in the open. Live nightclub and live concerts events are wonderment. The inner voices from audience as apart of the event is ear catching lifelike; you can count every finger touching each string of the instrument like the guitar. It's a transformation of a new record collection from my listening sessions. I wish I had got word of Eden Sound for my HRX Rim Drive sooner.

Anyway, thanks for the solution everyone pointing me towards Eden Sound.
It would be interesting experimenting using the Classic aluminum platter. Not sue if it’s compatible with the HRX? For sure the HRX Rim Drive will have an easier effort and less stress pushing the Classic platter than the heavy Super Platter with two acrylic discs sandwiching the aluminum disc in the middle.

In theory the pure aluminum Classic will induce vibration ringing compared to the Super Platter with damping on both end using acrylic. It’s an interesting point I like to share with everyone in this thread as you all help me so much.

When I first install the TerraCones on both the HRX motor drive and the HRX turntable footers, the touch point of the Rim belt was touching the top acrylic disc on the Super Platter. You can get away with 33 rpm but at 45 rpm you begin to hear a weezing spinning sound on the LPs. I think the acrylic is not perfectly uniform like the middle aluminum disc.

With the added adjustability of the brass cones underneath the TerraCones footers, I reposition the Super Platter where the Rim belt is touching the aluminum middle disc where its manufactured more evenly like the Classic platter. The weezing spinning noise disappeared like Houdini. The experiment suggests that always use the Rim drive on the aluminum disc of the Super Platter. If there is any minute noise, let the acrylic absorb it like the original design intention.

The TerraCones also enables me to perfectly level the Rim top plate with the Super Platter. To play with Rim driving the platter, it must be perfectly level on both spinning disc. My Clearaudio Bubble is centered perfectly on all surfaces of the turntable, Super Platter and Rim motor drive. The fine-tuning is necessary for best results.

Some of you may recall the esteem editor Myles Astor from his past Ultimate Audio magazine, recommends using Walker Audio damping discs on the HRX. I have four large Walker disc on the corners of the HRX Rim motor drive and two on each side of the tonearm base support on the HRX turntable. The fun is tweaking and hearing the improvement. Needless to say my Graham Supreme pivot tonearm is rock steady and doing the Graham magic. The Walker discs made perfect sound imaging and cleans things up. The Walker will eat up any spurious vibration.

I am still dreaming of a slightly larger heavier top plate on the Rim Flywheel to push the heavy turntable platter with better compatibility. I think VPI maybe doing something, but no announcement.

Thanks again.
Having great results using the new Edensound Terracones recommended by members of this thread to eliminate the vibes on my VPI HRX; I have decided to experiment with the Edensound dampers on the four corners on my Motor Flywheel HRX Rim drive. I have been using the Walker Audio 1 inch large disc for years to add additional damping to the Rim vibrations.

I am rather amazed that the new 4 Edensound damping discs (1 inch and 1 lb.) worked so well. Just using the Terracones footers has stopped the vibration when my fingers touched the Motor drive flywheel rim drive. After placing the 4 damping discs at the corners of the HRX Rim drive, and started the spinning turntable platter process, the damping discs was shaking and jiggling when I touch it with my fingers. That gave me evidence that the damping discs are eating up hidden vibrations on the Rim drive, although it "felt" non-vibration on the motor drive.

The improvements are deeper and well defined lively bass with added slam impact. The upper mid range and highs are crystal clean sounding. The smash on the drum cymbals are explosive. I found the tailing decays from each singer have added lingering musical notes.

I am quite impress the Edensound damping discs 1 inch 1 lbs. has added great value to the elimination vibration of the rim. However don't over damp using the 3 inch 2 lb. damping discs. It may filter out some treble highs.

It may depend on your set up to get these improvements. The fun is spending low costs to gain listening joy. I hope this info maybe of use if you are looking to eliminate more rim vibrations.