New foundation for my Kuzma 'brass pipe' TT

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Elizabeth

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New foundation for my Kuzma 'brass pipe' TT
« on: 14 May 2019, 09:46 pm »
Just ordered a new base for my Kuzma turntable.
The old wood plate under the Kuzma was a furniture store sample 18" by 18" of some exotic Brazilian wood now import banned, similar to Teak in type. IT was a flooring sample.. so it was 3" wide strips almost 1" tall... looking just like on a floor.. Stuck on a 1/4 particleboard type base.
Over the years it has settled slightly (being supported only 2" in from corners) and I have been seeking a replacement.
Well Cable Co has a (relatively) new brand. And all they make are racks and butcher block stuff.
So I ordered a 18" by 19" (3" thick) edge grain Walnut base.
I could have gone with Maple.. but having recently been exposed/enlightened to 'Tuning' vs just squashing vibrations... I decided to go with the more tune-esque Walnut wood.

S Clark

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Re: New foundation for my Kuzma 'brass pipe' TT
« Reply #1 on: 14 May 2019, 10:12 pm »
Please post some photos when you get a chance.  I was working on my Technics SP-10mkii plinth today.  It's a basic 4 layer Baltic Birch, but over the years it has slightly warped.  Time to run it through a planar and put a granite top on it.  The plan is also to drill and add lead shot around the turntable and by the arm attachment point. 

JLM

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Re: New foundation for my Kuzma 'brass pipe' TT
« Reply #2 on: 15 May 2019, 12:16 pm »
Vibrational (dynamic) analysis is complex.  Is the floor concrete or wood?  What is the construction of your rack, what is it's resonant frequency, and how massive is it?  How loud do you do serious listening?  What frequency is the table/base each tuned to and how massive are each of them?  If you want real answers you have to ask real questions.  I worked for 8 years as a structural engineer and hung around some very bright guys who knew dynamics, so I only know enough to ask the right questions.  So basically practically no one knows enough to pick out a proper base for a particular situation.

Audio bases are sold on the basis of look, feel, and price with very little true acoustical knowledge behind it.  Most make the mistake of putting a turntable on a wooden floor and then add bandaids to try reducing floor induced vibrations.  Combining materials is a good idea as mass is your friend and different materials have different resonant properties (when doing so recommend putting a pliable, but not too soft, bonding layer between them).  I use black 'woven' foam drawer mats between speakers and stands.

Same idea goes for floor, footers, and rack.  Think of the suspension on your car and imagine what the ride and handling would be like with metal tires, and very soft or hard shocks and/or springs.  Worn bushings alone make a huge difference.  Speed, mass, and size of bumps all must be considered in order to optimize performance.  Only amateurs would make the mistake of picking tires, springs, and/or shocks based on "look and feel". 

Elizabeth

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Re: New foundation for my Kuzma 'brass pipe' TT
« Reply #3 on: 15 May 2019, 01:10 pm »
Great comments JLM!
It is true I know nothing more than the typical audiophile 'guessing; at vibration stuff.
The rack is laughable (from the point of $$$ spent on electronics).. A former TV rack, square tube steel ends X braces, with a large rectangular tube one diagonal, and a thin tube as the other half of the X. The shelves are GLASS, and 40" long. The middle back has a strong wide vertical brace. And on the front under the middle I added a wood shaft 1" by 1" buffered with rubber ends to reduce the vibration and better stabilize the front middle weight bearing ability
One plus to the construction is I filled all the tubing with dried sand. It is old, and from back when I had far less expensive gear. Maybe someday I might replace the racks.. But probably not (unless I saw something that I just had to get)
The top shelf I have two TT on. Both have round patio bricks 5" diameter, 3" tall, with a rubber pad to the glass.
The Kuzma TT has size ten rubber bottle stoppers supporting (currently, and to be replaced with the new Walnut base) a 18" by18" store sample of some rare Brazilian teak like wood, as if a hardwood floor, so the bit of wood are cut 3" wide, 7/8" thick, and arranged to look just like a floor, so some cuts across the lengths some full size. but fill the 18" by 18" square, with an underboard of 1/4" pressed fiber. This is starting to sag very slightly after sitting for 7 years! Thus my planning to replace it.
The Rega  P-5 has a free to me 39 year old VPI isolation base (sprung) under it, on top of the patio bricks

With little knowledge other than 'putz grade one', that is the current state of the art for my TTs.
Would I bother further? no. Since I do not own the equipment to do any analysis, what would I do? Pretend?
I have been somewhat taken the idea that tuning may be worth playing with.. Though it is a arcane art, and not a lot I know about that either. Like it is the reason I chose Walnut vs Maple, and NOT for the look. rather for the change in vibration frequency of the wood. Walnut being a bit lower than Maple. From a 'Tuning' point of view. From a technical perspective. Tuning may be as crazy as aftermarket power cords... But musical instruments have resonances built in, and we all like those.. So after years of thinking all vibration as 'bad' I am changing my view that some vibration may be 'of use' in the quest for better sound.

I plan on playing with the new board and see if I can hear any changes to the sound with it in other places too. Since my main (tall) rack is also the same design and also has the same glass shelves, just 22" long. I counter the glass with size 10 butyl rubber bottle stoppers.. I use dozens of them as footers.
Since the suspended wood floor is all I have... I cannot tell the apartment building owner to 'fix' it.. (though if I chose to move to the first floor, THAT floor is pre-stressed concrete beams under it. (I would NEVER live on the first floor due to peeping toms and break ins..)

I also have the sense to keep the TTs as far away as can be from the speakers, and still be in the same room. The TT rack is 12 feet back from the closest side speaker, along the sidewall.
Plus the fact I play music typically at 50dB to 70dB at the listening position. (80dB is really loud to me, and I really only get that loud playing opera arias) SO not much speaker driven vibrations anyway getting into the floor and walls.

JLM

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Re: New foundation for my Kuzma 'brass pipe' TT
« Reply #4 on: 15 May 2019, 02:17 pm »
With wooden floors I'd consider an air bladder type of floating suspension and forget the rest.  Grounding the turntable to the soft wooden floor (via extra weight) is a bad idea.  And the old knuckle rap is a starting point to determine if a material is resonant (like your glass shelving). 

I recently bought matching rack and stands from Timbernation, lots of styles to pick from, easy to customize, heavy construction, and not too pricey. 

Elizabeth

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Re: New foundation for my Kuzma 'brass pipe' TT
« Reply #5 on: 15 May 2019, 02:24 pm »
I have never noticed any problem... And I would think that is the starting point once the pile is already in place. Why would I 'fix' something I cannot hear as 'broken'?
(other than to swap a board I have used and is fine, but warping, with one that seems pretty warp proof?
An air bladder... you have to refill it, get it right, adjust it, figure out how much air.. reinflate now and then... I look at an air bladder as a problem I do not need.
And since I can jump up and down in the floor and not disturb playback???
(aside from my downstairs neighbor banging back?)

ricmon

Re: New foundation for my Kuzma 'brass pipe' TT
« Reply #6 on: 15 May 2019, 02:36 pm »
I have never noticed any problem... And I would think that is the starting point once the pile is already in place. Why would I 'fix' something I cannot hear as 'broken'?
(other than to swap a board I have used and is fine, but warping, with one that seems pretty warp proof?
An air bladder... you have to refill it, get it right, adjust it, figure out how much air.. reinflate now and then... I look at an air bladder as a problem I do not need.
And since I can jump up and down in the floor and not disturb playback???
(aside from my downstairs neighbor banging back?)

Some pretty serious mansplaining  :lol: :lol: :lol: :lol:

rollo

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Re: New foundation for my Kuzma 'brass pipe' TT
« Reply #7 on: 15 May 2019, 03:02 pm »
  I have and use the same Kuzma TT with 12"VTA adj. arm. Over the years I have tried numerous plinths made of wood, Corian, Granite, bullet proof glass, etc.  Maple, pine, Walnut all have different resonance points.
  The distributor of Kuzma and expert TT Guru Scot Markwell and I worked on the plinth choice and maple  best suited the Kuzma. The plinth however was set in a plywood box filled with sand.
  The sandbox is 4" high and 14"x 18" inside dimension. Easy to make or have made. The sandbox is installed atop a spiked speaker stand with visco elastic pad between top plate of stand and bottom of sand box. This method eliminates ALL vibrations from floor to TT and soaks up resonance from TT and dissipates as heat into sand. BTW periodically turn the ring around footer as it sags and loses its function as a buffer.
  Great TT BTW. The most cost effective solution we found as a bonus. Have fun trying.


charles

Elizabeth

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Re: New foundation for my Kuzma 'brass pipe' TT
« Reply #8 on: 15 May 2019, 08:04 pm »
I am trying Tuning a bit. Not total isolation...
Which means the TT can experience some vibrations. Not equivalent of a Black Hole....  :thumb:

woodsyi

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Re: New foundation for my Kuzma 'brass pipe' TT
« Reply #9 on: 16 May 2019, 01:04 pm »
How do you level your TT?

sunnydaze

Re: New foundation for my Kuzma 'brass pipe' TT
« Reply #10 on: 16 May 2019, 02:41 pm »
How do you level your TT?

I once owned the Stabi "s" turntable.   It has no adjustable feet for leveling so what it sits on must be perfectly level.  If it sits on a platform, which then sits on a shelf, you can use a platform that has built in adjustable feet or shim it somehow.



To make tiny adjustments on mine I simply cut small pieces off an old thin flexible chopping mat and placed it under the rubber O rings that support the table (or between platform and shelf).

https://www.amazon.com/Clear-Flexible-Cutting-Chopping-Mat/dp/B00BOUUX6G

Old credit cards also, or anything that is thin flexible plastic.

BTW, great table!    :thumb:

sunnydaze

Re: New foundation for my Kuzma 'brass pipe' TT
« Reply #11 on: 16 May 2019, 02:52 pm »
PS:  photo above is from my old FS ad.

I sat the table on a maple BB platform, which sat upon a maple BB DIY rack.  Between them I used Herbies tenderfeet, or a similar anti-vibration pad. 

https://www.supplyhouse.com/DiversiTech-MP-2E-EVA-Anti-Vibration-Pad-2-x-2-x-7-8

Sounded fantastic so I never felt the urge to tweak it or try different isolation devices.

BTW, Kuzma sells a platform designed to be used under the Stabi "s" that is nothing more than a plain old Maple butcher block.  So I guess they believe it's a good approach.

Elizabeth

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Re: New foundation for my Kuzma 'brass pipe' TT
« Reply #12 on: 16 May 2019, 03:01 pm »
I have used "Post It" notes slips of paper to adjust the level of both the Kuzma and the Rega bases. At Rega feet. Never did it at the Kuzma O-Rings though. (since the Kuzma is on a wood platform, I can adjust the platform to be level.
The Post It note pads were 'at hand'  :thumb:

sunnydaze

Re: New foundation for my Kuzma 'brass pipe' TT
« Reply #13 on: 16 May 2019, 03:12 pm »
Post-it notes.....plastic bits.....credit cards....business cards.....playing cards....anything that gives the correct thickness.  And I stack them if I need to.

I don't get too anal about the material used, and how it will (or if it will?) effect the sound.  Everything is so rock solid and heavy in my rack, and that's what I mainly concern myself with -- mass and solidity.  I can jump up and down on my suspended wood floors such that I can see my rack shaking, yet the needle never skips. Air bladder and silicon trough in my Townshend Rock 3 helps in this regard,  but my Scheu is an unsuspended mass-loaded design and it plays unperturbed.