Decoupling turntables from floor vibrations

[Lee in Montreal]

Development has evolved into 3 versions for 3 budgets. The version with base and subframe is definitely way too expensive to produce and will be costly to retail in its actual form. But it will remain available for those with deeper pockets. I have developped three alternatives that are equally sexy. The cheapest one being $100.00usd

Four sets of the initial version are currently being tested. Will need two more beta testers for the next generation. Must have SL1200 TTs and preferably a nicely set-up system. Not one put together on a kitchen counter ;-) And preferably people suffering from floor vibration problems. When I see people bolting frames to the wall thinking it will solve the problem, it makes me dizzy...

[Wagner]

When I see people bolting frames to the wall thinking it will solve the problem, it makes me dizzy...

Cannot imagine why? The practice solves many problems and solves them very well, especially when augmented with any sort of secondary isolation

[Lee in Montreal]

Cannot imagine why? The practice solves many problems and solves them very well, especially when augmented with any sort of secondary isolation

Wall is attached to the floor. Vibrations from the floor are transmitted to the wall. Then somebody slams a door. Oscilations will reach the turntable from the wall. Wall vibrates from low bass thumping. Then thean reach the frame.

Lee

[Wagner]

Wall is attached to the floor. Vibrations from the floor are transmitted to the wall. Then somebody slams a door. Oscilations will reach the turntable from the wall. Wall vibrates from low bass thumping. Then thean reach the frame.

Lee

Did NOT say or imply that a wall shelf was the penultimate solution for turntable isolation

I also thought I was clear when I said shelves were a good approach, when AUGMENTED with secondary isolation

AND assuming the installation is an intelligently done one (you don't bolt the steel frame directly to the sheet rock for example) I use heavy neoprene insulators you can pick up at any good hardware store and fuel injection hose cut to length through the frame where the mounting hardware passes; the shelf structure itself never comes into direct contact with the wall

A shelf will/can be installed to put a turntable at a good working height as well and doesn't require another piece of furniture or equipment rack to employ (again, freeing up floor space to be better used in smallish rooms) A well mounted shelf will also get a deck out of the "line of fire"

Where practical, a well designed and properly mounted wall shelf for a turntable is as valid a solution as your creation; in fact, the two could be used in tandem and I would venture to suggest with excellent results

Your reaction to their use, that it makes you "dizzy" was a bit over the top, ergo my post; again, I never said it was the complete and final solution or a competing solution with your idea

I have used wall shelves for years and when combined with good secondary isolation or footers works just fine, and once leveled it stays that way (I have also made 100s of Lp to tape transfers with no ill effects of transient pollution or impulse noise in the noise floor, none that was audible anyway and I am running some very light trackers at times

If one lives in a building constructed so poorly as what you propose, then any table weighing in at more than 10 lbs is going to be swinging the breeze on those rubber bands; you've got to put your creation on SOME flat surface now don't you?

And obviously my comments apply to permanent/semi-permanent installations; your device lends itself well to applications requiring portability

[Lee in Montreal]

The past weeks were spent simplifying the idea in order to lower production and shipping costs.

The base frame has disapeared. Replaced by two shapes of feet. Tetrapod (left) and tripod (right). The tetrapod is more stable at the moment. The tetrapod will have four rubber pads underneath and the tripod will have wide stainless/rubber feet which shall increase stability. I will chose one or another. The subframe itself has been beefed-up and is now thicker.







The original Technics rubber feet can be removed and replaced by those. It lowers the turntable. Reduces costs and will most likely appeal to clubs. All they will have to do for an install is to get those flat feet and screw hooks under the "counter". works at home too.







The posts have been redesigned too.

[Wagner]

Keep in mind that the 6mm threaded inserts tearing out/coming out of the rubberized bottoms of SL-1200s (later models) seems to be a problem for some reason (never could figure that one out for certain, how this is done; only know that it seems to be a common failure)

Lateral/stress on the horizontal plane?

The simplified hook replacements for the footers may not work (well) on all decks; don't know if the lateral (angled leverage) stress now applied by their use will exacerbate this "phenomena" over the long haul or not?
Don't know how they can be "pulled out" without damaging the hole to some degree?

From "KAB"'s site:
SL1200 Stock footers do a good job overall of isolation and offer an easy way to level the turntable.
Time proven design of spring loaded elastomer damped suspension with 6M threaded stud. They do wear out over time though and can lose their "as new" height. so it is best to replace tired old footers when this happens.
KAB also has the threaded insert which goes into the rubber base. Sometimes in rough handling these pullout and go missing.

[svollmer]

I was one of Lee’s beta testers. Lee was kind enough to send me one of his isolation bases along with hardware, accessories, and rubber bands. Below is my experience with his device.

My Setup:
Technics SL1200 MkII Turntable
Audio Technica AT120E Cartridge
Creek OBH-15 Phono Preamp
Mark Levinson 380S Preamp
Mark Levinson 332 Power Amp
Legacy Focus Loudspeakers
Four DIY 2245H Subs
Audio Control Richter Scale III Crossover (set at 40Hz)
DIY Maple Butcher Block Equipment Rack

Background:
I listen to most of my music from CD’s. But, I also enjoy listening to records, especially the ones that have never been issued on CD or are now too rare and expensive to purchase on CD. I would call my turntable setup as “nice functionality.” It’s certainly not extravagant or expensive, but it’s competent. I grew up with Technics turntables and when I had a chance to purchase a brand new SL1200 a few years ago, I jumped on it. When playing records, I’ve noticed that the Technics has a quieter background with the dust cover off. I can also hear a clear “boom” through the speakers if I wrap my knuckles on the butcher block stand or even if I just tap my finger on it. However, when records are playing, I’ve never noticed low frequency feedback coming through the speakers. So, I always assumed the butcher block stand was strong enough to isolate the TT from acoustic vibrations even though my light strikes on it from my hand produced noises.

Assembly:
Assembling Lee’s isolator was easy and straight forward. I chose to use the tripod feet only because I liked the look of them better than the tetrapod feet. The machining on all the parts was very nice. Lee has continued to refine and improve the design. The feet in my kit came with flat head Allen screws to attach the posts and the bases were machined so the Allen screws sit flush after installation. You can see in the picture that it’s flush on the bottom. I placed beer coasters under each base. The posts were machined very nicely and certainly do not look like a DIY project. I chose to use two rubber bands per foot. I tried three, but they seemed too rigid to me.

Impressions:
All I was hoping for with the isolation base was that it would reduce the microphonic sounds that I regularly heard if it picked up or placed objects on the butcher block near the turntable. It certainly did that. With the turntable not spinning and the tonearm down on a record, I tapped on butcher block with and without the isolation base. The sounds picked up by the TT were greatly reduced with the isolation base. What I didn’t expect was an improvement in the overall bass quality in recordings. It’s not that I heard “more” bass with the platform; I heard bass that was more taught and defined. It wasn’t miraculously better, but it was better. It’s possible that the reduction in microphonic pickup while a record was playing was reduced (even though I hadn’t noticed it before) and that led to the impression of tighter bass.

One observation I had was when I accidentally bumped my rack with my leg. The side-to-side energy I induced into the rack was reproduced by the isolation base as the turntable gently rocked from side-to-side on the rubber bands until the energy dissipated. The caused the tonearm to gently skip across the record. So it seems that the isolation base is very good at reducing vertical (up and down) energy and vibrations, but doesn’t reduce lateral, or side-to-side energy. But, I found a fix for that; I didn’t bump the rack on the side again! 

Value:
I recall in an earlier post Lee saying the target price would be around $100. For what you get and for the quality of the pieces, I think that’s a very fair price. Compared with all the other accessories one sees in the high end world at shockingly high prices, I’d say this accessory is a bargain. At the above price, I would purchase one.

The suggestions I have for Lee are purely aesthetic. If there is a possibility of anodizing them black, some people may prefer that as it would make them more invisible, depending on the neighboring surface, equipment, etc. If there are black rubber bands available (I recall Lee ruling out O-rings), that might be a nice change too. I’m fine with the regular rubber bands as they are functional, but some may feel reluctant to have rubber bands in their high-dollar rig. Also, if this goes into production, it will need to be packaged properly. It doesn’t have to be exorbitant, like some interconnect cables, but it should reflect how nice this is and have “branding”.

Overall, I would say Lee has a great product here and I think he wouldn’t have much trouble getting it into the retail accessory market. I bet many of the online turntable and accessory dealers would be happy to add it to their offerings. Great job Lee!

Steve

[svollmer]

A couple pictures from my setup.

[Lee in Montreal]

Thanks Steve for the report.

The parts you received for testing are pre-production and the surfaces aren't finished. On the end product, the aluminum would be anodized. I will probably offer black and clear anodize.

About the shape of the corner bases. One is tripod and the other is tetrapod. I recognize that the tripod looks very nice, but sadly it is not as stable as the tetrapod. So, if I have to chose between form and function, I tend to pick function. Hence the final kit will use the tetrapods seen on the left. The tripod could be used if the inner pod is bolted/screwed. One change I was intending to perform on the posts was to make them perhaps a 1/4" taller to accomodate people fitting softer rubberbands. The bands being softer, the turntable will be lower. Tell me what you think.



About filtering the vibrations
Filtering vibrations is one thing for which the kit is designed. But filtering movements such as in hitting the rack is another. ;-) It would require longer distance between the rubberband pick-up points, and way softer rubberbands. The softer the suspension, the lower the frequency it filters. Then, if the suspension becomes very, very soft, many people will have a hard time handling the stylus without shaking the turntable. It's all about compromise.

Options
I supplied Steve with a few optional components. The two styles of pods are one option. But it also came with "hooks" and spacers that bolt in place of the rubber feet. THose were perhaps intended for fixed installations where people cut square holes on a counter, lay rubberbands and put the TT on top. That way, the turntable ends pretty much flush with the counter which is usually made of two layers of 1" birch.

Or it can be used at home, without the subframe.





The thin alu spacers I mentionned in the previous paragraph can also be used if bolting the turntable to the subframe. That is by removing the original rubber feet. The prupose is to get a lower turntable. Am I also reducing some vibration filtering that came from the rubber feet? Not necessarely I think. That's because the rubberbands filter at a lower frequency than the rubber feet. Maybe Steve can test that. ;-)

[Sean Dab]

I'm so in need of these!





As you can see, our setup is resting on a deck with tons of movement. Was debating on hanging the whole rig but now I think the best bet is to float the turntables and use cutouts with rubber suspension. Hardware available? The hook / feet replacement hardware is the ticket

Thanks, Sean / Dj Dab