TW Raven Owners: Set Up Questions


Through the magic of sweet talk, I turned my Orbe into a Raven and mounted my Graham 2.2/Benz LP.
I am looking for a isolation base for the Raven. I have a 1 3/8" piece of granite coming soon so I can ditch the MDF I use now (a temp. meas.!) Symposium, SRA, HRS, etc., can anyone share their experiences with isolation bases? I saw the thread about loosening the Stillpoints.
Initially I had an issue with using the rough side of belt. The belt shimmied up/down on the pulley at a specific spot on belt. Also, the speed fluctuated and I could never get it dialed in with the PSU. So, I went to the smooth side of the belt and then raising the back side of the motor (unscrewing one of the isolation feet) slightly moving the belt down from "center" on the pulley. This moved me from 33.2 to 33.3 and I have no more belt shimmying and the speed is rock solid.
I'd appreciate any tips/tricks etc.
gerardff
It's hard to beat a wall-hung shelf (especially if mounted on a masonry wall) for reducing the effects of structure-borne feedback?
I use factory bench with 4 inches slap of black granite right now with my TW. I have a friend that in the past had tried quite a few different types of stone for amp/speaker stands etc before and he found best result using black African granite (supposedly it has higher density than average granite!) In the past I tried slate but the result was not great. At least for those that I could find locally anyhow. I was trying to get a quarry to cut me pool table slate slap and it was a big hazzle and trying to get them to polish slate smoothly was almost impossible (may be I need a pool table factory for this). Anyhow, the one I got was not so great. However, I just located a used Symposium ultra locally that is big enough for my Raven AC-1 so hopefully I will try that in the next few days.
Vibraplane is also something I want to try or perhaps Minor-K. However, I am still thinking that eventually I might try to get BN 3 motors unit for my Raven so until I know for sure what size the turntable platform will need to be, I don't want to invest a lot on platform for my turntable just yet.
I use a wall shelf and have tried a number of isolation feet. The problem with heavy granite slabs is the wall shelf might be overloaded. You don't want the table falling off the wall.
I have used a number of feet, stillpoints, black ravioli, Herbies Isocups. the New stillpoint SS Ultra are marginally better than stillpoints+ risers, not enough to justify the added cost, but better
In addition to the above, granite can be OK if damped by gluing linoleum to the underside.
I have experimented with a variety of mounting possibilities for my TW AC 1, starting with a granite base(not good, a bit of ringing) to a HRS platform sitting atop an acrylic stand( not recommended). The AC1 has been tweaked with a BN PSU and motor. This required more real estate and led to a wall mounted 2.5" mdf shelf on brass cantilevers. Wall mounting is by far the best if it works for you. The AC rests on a HRS platform while the BN motor has a separate mdf platform and the whole package is on a wall mounted mdf shelf that can support upwards of a 100 kg !
Any of the well known iso platforms should work well. I would urge caution regd the feet. Any hint of rubber or non metal in contact with the feet can deaden the sound ,as I discovered. I have the HRS couplers that consist of a round metallic plate with rubber dampers on either side. Initially, I had the 3 TW footers resting on the metallic coupler sans the rubber damper on top.Sounded good but removing HRS couplers led to dramatic improvements.
Use only the TW arm board as opposed to a wooden armboard .
All the best
Pradeep