Additional Isolation mounting feet or other for VPI Classic ?

MikeCh

MikeCh

Active member
Joined
Nov 25, 2013
Messages
1,961
Location
Colorado
Those of you with a VPI Classic, do you go the minimalist route and just use the stock HRX feet coupled/resting directly to the top of your audio rack? Or, do you use any other combinations of say butcher block + other specialized feet between any additional platform and the rack, etc.?

My rack is sand filled and weighs about 150 pounds, sits on spiked feet in brass cups on a concrete basement slab. I get no footfalls or other extraneous noise radiating into the gear from outside the rack that I can determine (used my wife's smartphone with an app to measure vibrational energy the other day). However, if I tap the rack itself or the butcher block under my TT or the plinth itself, I do hear thumps in the speakers with the phono switched on. I don't make a habit of bumping things on purpose to make thumps, but it does concern me that I've not got something isolated as well as could be.

edit: I should also note, that I'm not using the internal phono section of the ARC preamp, but instead a Lehmann Black Cube SE II into the "spare" line level input on the ARC. Perhaps I need to try isolating the Lehmann a bit too?.......hmmm.


Any recommendations?

Here's a picture of my setup as it sits today: (note the 3" thick butcher block and HVAC type isolation pads between the BB and top of rack, these are 3" square each x 4)

attachment.php
 
The idea with a platform under your table is, you want the resonance frequency of the platform to resonate at a lower frequency than the table/plinth, that would be the ideal approach. Maple doesn't have a low resonance frequency, it excites rather easily.....Another thing to experiment with is instead of using de coupling materials under the maple platform try the coupling approach (rigid materials like cones). Using less compliant footers under the maple platform makes for an easier pathway for stored energy to travel down and away from the turntable. Your table has semi compliant feet so I would not go towards a more compliant footer but a less compliant footer. One last thing is trying the table directly to the top shelf. At the end of the day look for what sounds best not what passes the knuckle test. As always YMMV!
 
Thanks for the advice Nelson and Jeff!

Since I've been running this setup in this manner for some time now I have to admit, I don't recall what it sounds like without anything between the HRX feet and the rack. I suppose I should break it all back down to the basics and listen to see if I can do away with all or portions of the isolation I now have in place. Then tweak from there if the stock feet alone and resting on the rack doesn't do the trick.

I started playing with isolation before I really got to know the "stock" turntable or confirmed additional isolation was needed in the first place. LOL.
 
You must log in or register to reply here.
Back
Top