I renamed the system. From Twin Platters rim drive it is now a Classics tournament: I will compare fairly 4 classic TT : Thorens TD 124 MKII, Garrard 301 and 401, Lenco L75 PTP3 on same slate plinth with same(TD124) slate armboard and same Phantom tonearm in same system. The TD124 is finished, now the Lenco is following...
Classic original bough cheap to upgrade with 26 Kg slate plinth/ PTP 3 topplate/ 15 Kg platter (VPI Superplatter) on top of Lenco L70 platter) Still not finished, a slate top plinth / tonearmboard has to be done, with motor controller to eliminate all the switches.Stainless steel platform between the two slate layers.
Thorens TD-124 mk II / Slate
Heritage from my father. Slate plinth designed by me and made by Oscar Daffe in Belgium. Major upgrade . Slate tonearmboard. Various Schopper upgrade kits . Symposium couplers.
VPI Industries TNT III modified turntable
I used the old platter as a RIM direct driving the new superplatter via rubber belt around it .The whole TT plinth is sitting on 3 Symposium Rollerblocks Jr. on Ultra platform. You can see on pics that the plinth feets are just for visual matter. Rubber belt replaced by Loricraft thread line between motor and rim drive platter. The rollerblocks tungsten balls are a smooth horizontal pressure to rim platter acting as a controlled buffer for vibrations and increasing speed accuracy, and on vertical plane acting as direct coupling TT plinth to the Ultra platform draining energy to it. The accuracy of this TT is much improved.
Symposium Ultra Platform
Specialy made for VPI TNT with RollerblocksII direct coupled to TT platform bypassing the footers. The whole TT is resting only on 3 tungsten balls.
Symposium Rollerblocks II tungsten
Direct coupling TNT III plinth to Ultra platform on vertical plane and applying a controled pressure between the 2 platters on horizontal plane.
VPI Industries SDS speed controler
Synchroneus drive to 300 RPM SAMA reverse wired
Allaerts MC-2 Finish Gold cartridge
Stereo cartridge
Allaerts MC-1 mkII
O.6 mV MC very musical.
Graham Engineering Phantom B 44 tonearm
With two armwands
Lyra Helikon Mono cartridge
Mono cartridge
Purist Audio Venustas Tonearm cable
Tonarm cable DIN to RCA
TRON Tron Seven tube phonopreamp
Optimised by Graham Tricker for Allaerts Finish cartridge. Very high gain (>75dB)
SME 3009 mk II tonearm
on Thorens TD 124 mk 2
Nagaoka MP 50 MM cartridge
MM High resolution cartridge. As good as the Allaerts ! OK with GSP Revelation phonopre.
Garrard 301 Hammergray grease
Very early 1954 very good condition
SME 3012 MKII tonearm
With Garrard 301 Hammergray
Garrard 301 oil bearing
strobe platter
Garrard 401 turntable
early model, very good,very quiet and stable
Perpetuum Ebner P 33 Studio turntable
This is my favourite jewel, 1963 idler/belt like the TD 124 but mutch smaller. I will keep it as it is, with the absolutely gorgeous tonearm.
Graham Slee Elevator + Revelation
Phonopreamp direct connected to MC 275 via Purist Proteus Provectus IC using MC 275 volume controls (bypass a preamp). Has 15 different recording curves and mono switch for vintage albums.
Purist Audio Proteus Provectus RCA interconnect
SE interconnect phonopre to MC 275 amp
McIntosh MC-275 reissue modified
With NOS Telefunken/ Mullard military small tubes NOS ECG Philips 6550 tubes
Quad ESL-57
Pair of mythic Quads refurbished by One Thing Audio in U.K. / Sound is gorgeous, clean and accurate, paired with ARC VT 100 amp.
Martin Logan Ascent i
Hibrid electrostatic
Mordaunt Short Subwoofer
MS 309 Sub very fast and matches well ML Electrostatic panels
Loricraft PCR 4 Modified
Record cleaning Machine. I put damping tissues inside to lower succion motor noise.
Nicely done; detaching the bearing and support for the rim drive platter from TT plinth should have reduced conduction of vibration into stylus. Hopefully it's quieter than VPI's own rim drive cassette, which apparently requires soft feet to add compliance back into the system.
It's interesting that despite the heroic effort of a rim drive wheel with even greater inertial mass than a stock VPI rim-drive flywheel, you found that speed stability was perceptably compromised by even a single elastic rubber belt in the sytem. My guess is that you've about reached the limits of the design-- assuming you're using a good speed controller to quiet down the 300 RPM motor.
Since even thread has some elasticity, the only place to go to further reduce compliance would likely be tape as advocated by Doug, or to a direct-coupled, high-speed, high-torque motor-- such as was used in some classic idlers. I tried a less elastic alternative to carpet thread-- Stren braided fishing line-- but was unable to get it to grip well.
There is useful info on the Galibier site on how to make a tape drive:
http://www.galibierdesign.com/support.html
You would need to make a custom pulley or employ a lathe to cut a smooth channel into the stock VPI pulley. While perhaps not quite as stable as tape, thread drive is easier to implement and IME improves upon a VPI rubber belt.
Nice mod that should surpass the speed stability & quietness of VPI's own rim-drive, due to the higher mass of your drive platter and the slower rotation and wider contact area of the O-ring at the interface. Using the spare platter for this purpose helps justify costly upgrade to HRX platter.
Did you reduce compliance in the drive system by eliminating the TNT's sprung suspension? For reduced compliance & increased speed stability, it might also be interesting to try multiple belts or thread or tape drive between the motor & the rim drive platter. Where did you source the O-ring?
