Modified dualdrive turntable ends search

by pedrillo on All Out Assault
Dual Drive system
Another view
magnetic repulsion
Added mass to platter 28 lbs. ofleadshot
Drive system, old platter isda flywheel
previous incarnation of modified tt

Description

I have discovered that the source makes or breaks the system, therefore I put some time into improving the turntable. It started off when I made my own platters out of acrylic and within the platter made cylindrical encasements to hold leadshot. I also replaced the feet with my custom made acrylic tubes again filled with leadshot. I kept using acrylic and leadshot for the tonearm board support and the bearing holding structure to avoid drilling out the original plinth since I was installing the latest vpi hr-x platter weighing in at 33 pounds or thereabouts and the bearing is much wider in diameter than the original bearing. Each time I made an improvement the source became quieter and so much more was coming out. Very happy to say the least. Also need to point out that the turntable is swinging off steel cables, so I like to think of it as the tt being somewhat decoupled from the room. There are some bungie chords as part of the suspension system for the turntable. The whole thing weighs right around 400 pounds some of it as part of the flywheel assembly. I would say the turntable is about 250 pounds. Also on top of the platter rests a weight also composed of you guessed it acrylic and leadshot, well there was this sale and I couldn't resist. Also using the periphery ring. And on top of the cartridge is oh I hate to say it so I'll let you figure it out. How it sounds is all that counts, so I can say enthusiastically it's beautiful. Not the end all, but it never will be in this crazy hobby, gottta love it!!
Read more...

Components Toggle details

    • VPI Rim Drive HR-X
    Rim Drive
    • VPI Industries TNT-5
    Far from what I had purchased 2 years ago used here on gon. It's total weight around 430 pounds with custom flywheel assembly.
    • VPI Industries TNT-5
    Another view of the flywheel (from old tnt model) that needs 4 motors (3 motors shown here from previous setup, added motor since then) to spin the 95 lbs. of rotational mass. An intermediary pulley (old flywheel) is used to transfer rotational force to record loading platter. Cannot find belt long enough to span two platters hence the in between pulley.
    • VPI Industries TNT-5
    An old incarnation of this ongoing project. This picture was taken before leadshot donut was attached to underside of platter.
    • Flywheel VPI
    String driven figure 8 to create better trcation
    • Flywheel VPI
    Stand alone Flywheel
    • Modification Magnetic Repulsion to platter
    Since adding leadshot encased in acrylic to underside of platter I needed to lessen load on bearing with this magnetic repulsion system.
    • VPI Industries Vpi
    With tons of lead shot
    • VPI Another veiw
    Lots of lead shot
    • Modification to Graham 2.2t
    Leadshot stuffed into little canister and straw attached to wand of tonearm.
    • Denon Denon/zu 103r
    103r
    • K&K Phono stage kit
    Awesome, totally awesome. One of the best at this price point, highly recommended!
    • JLTI Phono
    Excellent phono, beats my ear 834p and approaches the K&K phono stage
    • EAR 834P
    Awesome phono stage for the money, should be modified with better caps and tubes!
    • oppo 980
    An out right bargain of a cd/dvd player, highly recommended!!
    • Sony DVP-S9000es
    Nice player.
    • audio experience a2 se
    Very nice preamp for the money, was quite surprised.
    • Sim Audio Moon P-5
    Suspended by bungie chords and loaded with lead shot.
    • Sim Audio Moon W-5
    Awesome ss amp, most highly recommended!
    • Atma-Sphere ma60 mark II
    Lights up the room in more than one way WOW!!
    • Merlin Music Systems VSM-GEN III RC
    Suspended by cables to keep floor from resonating
    • Merlin Music Systems VSM-GEN III RC
    Another view of the suspended system
    • Martin Logan Depth
    Suspended with steel cables from ceiling above full range.
    • Alesis Masterlink 9600
    Cd burner with hard drive to pre-record (to do editting or equalization) before transferring over to cd.
    • Merlin Bbam, Balanced
    Makes the speakers sing as they were designed to with this bbam.

Comments 109

Sign in to comment
Owner
Thanks for the nice words, I AM NUTS. At least I know it.
Yes I am having a blast. My next step is to add some lead shot to the bottom of the main platter. I have the design in my head already it's just a little labor intensive. I would like to encourage everyone to take an active role in tt setup. I think one easy first step would be to discouple the tt from the room. I never agreed with the shelf on the wall vs. a floor stand. If the floor resonates from the music or other sources of vibrations why would the wall not resonate as well. I may be missing the point so if anyone can explain I am all ears. In any case the room and everything in it will move, vibrate, resonate and shake. Put the tt outside of this and you will have improved things a great deal, if you take into consideration how little the distance a needle moves to make sound you will realize the significance of this decoupling business. I didn't want to move the tt outside of my room, who wants to walk extra steps to reposition the the needle or flip the record. Therefore I hung my tt shelf with steel cables. It's not that hard to do. I went an extra step and let my flywheel and motor section sit right the shelf this way there is that one less source of vibration from entering my cartridge. I hope I made a difference, any questions feel free to ask. Have fun and enjoy the music.

pedrillo

I mean this in the nicest way possible - you are nuts! What a great setup... I can tell you are having a lot of fun with this. If I had the skills you did, I would probably be just as obsessed.
Thanks for sharing!

transmissionfluid

Pedrillo,

You might try tight carpet thread tied with a flyfisherman's blood knot to smooth travel of the knot through the grooves. There should be enough grip.

I may make a tall centerweight as well. I'm tempted to try ebony. I read posters who like the Shun Mook ebony clamp, and am amused that the Shun Mook web site admits that the clamp introduces resonances to the stylus of an additive, euphonic nature. This is not typically what audiophiles strive for, but whatever works... It may be difficult to emulate the Shun Mook resonances, however, as the monks claim to use a rare ebony found only in remote swamp environments. Perhaps a safari is in order.

I'm sure that the heroic mass loading on your TT is successful at resonance control and that the big flywheel has achieved great speed stability. Your TT is so far from any current commercial offering that no-one who has not heard it is qualified to comment.

dgarretson

Owner
Dave,
I would have liked to do away with the intermediary small flywheel but cannot figure out how I would drive the main platter without an oversized belt. Even if the belt existed I wonder if there would be too much slop since there would be a greater distance between the platters than between the small flywheel to each platter.
The center record clamp is around 6 pounds. Yes there is enough benefit to justify using it though I have not done an a-b terst recently. By the way from what I gathered from speaking with VPI the old bearing should be up to the task but I would give them a call to confirm.

pedrillo

Pedrillo,

I was looking once more at your TT set-up and have questions:

Did you ever try using the second flywheel platter connected directly to the primary platter, rather than through the intermediate small VPI flywheel? There are theorists who believe that a full-sized platter makes the best possible flywheel. The effectiveness of the second platter in stabilizing speed might actually be diminished by slop in the belt drive system associated with passing through the small intermediate flywheel.

How heavy is that record clamp? How much benefit does it provide on top of the HRX platter? I am considering making a heavy record clamp for my old TNT black platter, but I am uncertain whether the old-style non-inverted bearing is up to the task.

Dave

dgarretson

Hello, Look at your VPI turntable pictures, I couldn't understand why it need that heavy for. Music come out from speaker, yes! everything right there, just right there, just feel cold and feeling without Heart.....What we want music to be is to have contact between singer & listener. The metal Ring clamp is the worst, metal is the worst enemy of all. It is because they all ring loudly and resulting in bad sound! The less metal left on turntable the better. Good things, such as maple, oak, pine, ebony........, go for Oracle V & Shun mook Clamp. Simply the best! So much for now, happy listening ! Sorry for my bossy....:o)

hillyau

The improvement in speed stability of low-compliant thread drive relative to VPI elastic belts, is quite audible. But the thread tends to slip-- particularly around the small 600 RPM motor pulley, but evidently also around the 2" flywheel pulley, and also around the platter. The solution is a small freewheel tucked into the pulley on the slack side of the drive system at motor, flywheel, and platter. This obtains close to a 300 degree wrap of thread around the circumference. The idea is similar to the freewheel used by Frank Schroeder in his new tape drive TT. I think that the elasticity of the stock VPI belts is a source of slurring in VPI TTs regardless of drive controller, motor, or flywheel configuration.

I'll post a few pix when I'm done with the pulleys & cantilever for the platter/flywheel segment, but here is a photo of the motor pulley:

http://cgim.audiogon.com/cgi-bin/vs.pl?vaslt&1140494870&viewitem&o6

dgarretson

Owner
Belts are vpi's. Would like to hear about your machining pulleys. Thanks for looking.

pedrillo

Very interesting non-factory updates to the TNT! I'm also working on mine, though from a quite different angle. I'm in process machining more pulleys for the thread drive. What are your belts made from?

dgarretson

Showing 101 - 109 of 109 posts
  • 93.7K
  • 109
  •  1
© 2024 Audiogon.com