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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
hiendmuse
257 posts
 
Krell,

I have the VPI SSM with rimdrive and Edensound Bear Paws which sit on a Symposium Acoustics Ultra shelf. I strongly recommend that you do NOT use the roller blocks under the Symposium Ultra shelf for your VPI SSM rimdrive. The Ultra shelf is superb, but you do not want any lateral movement which can cause problems with tonearm rocking which can be transmitted by the roller blocks. The roller blocks are excellent under a CD transport.
stringreen's avatar
stringreen
6,525 posts
 
Hiedmuse is absolutely correct. The reason for the Bearpaws is to eliminate any movement whatsover. Rollerblocks will only make it worse.
krell303 OP
40 posts
 
Problem solved!!! I've got SolidSteel 6.3 rack, placed Symposium Ultra platform on the top (via Symposium Couplers), replaced the original SSM's feet with Edensound's TerraStone TerraCones (custom model for VPI SSM, height-adjustable via solid brass cone tip and brass knurled locknut, and complete with point-receiver) and ... WOW! It was like adding sub to the system + I hear much wide soundstage, pace and rythm are unbelivable on Ray Brown's "Soular Energy" LP. VPI SSM tonarm is rock steady now and there are absolutely no microfonic effect I've experienced while using TerraCones only.
P.S. I've tried Edensound Bear Paws too with almoust similar effect - but decided to stay with TerraCones to avoid scratching Symposium's surface with the sharp Paws points.

Stringreen and Hiendmuse - thanks a lot for sharing your experiences! By the way RollerBlocks Jr. now are sitting under my Sony SCD-XA5400ES SACD player
stringreen's avatar
stringreen
6,525 posts
 
Good place for those RollerBlocks.
gja
1 posts
 
Krell303

I went through a similar issue converting my TNT HR5 to a rim drive. My problem was with pitch variations. I ended up replacing the air bladder feet with large brass cones and setting the rim drive pod on a sorbathane/acrylic bed and steel cones. This has made a vast improvement but requires some intermitent tweaking to keep the pitch steady. When it's on - the rim drive totally beats the belt. I'm in Central Jersey if you ever want to compare notes.

Andy
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