homemade turntable vibration isolation platform


Out of a couple years of frustration, I irrationally tried to create my own turntable suspended platform to cure two problems. First, footfall would often jar the stylus enough to skip and my music seemed muddy/blurry. The floor bounced enough to make us have to tip toe through the living room. It was getting where I would hate to even play a record. I went searching for tweeks. Ideas abound. Ropes from ceiling, etc. But I live in a yurt. Everything moves, including ceiling beams. Floor works like trampoline (almost). Out of complete desperation, I drilled holes in the top of my component cabinet (double 3/4" plywood) and suspended my turntable on another piece of plywood by bungees from four posts. I got lucky!! It worked fantastically. One could almost jump up and down in the room (my wife tried). AND, a solid bass appeared, soundstage grew a third larger, the clarity was enhanced exponentially. Pure luck I cured my years of frustration and got an indescribable upgrade sound quality besides. After 6 tries I've recreated a free standing unit that works as well. Just had to share.....  


allears4u
I once had my turntable suspended with chains from the ceiling to a 3/4" plywood base I made for it. Worked just fine. That was when my system was in a room over a basement. My setup now is in a room with concrete slab floor so no vibration unless I get out my jackhammer.
OK, great,

now we need you to do a thorough job describing your solution please.
3/4" plywood square, eight hooks, four 48" lengths of chain, air compressor, jackhammer. Got it?
I had to look up what a "yurt" was and based on google's response, I could only imagine that equipment isolation is only one of your system challenges. 
People who live in grass yurts shouldn’t stow thrones. 
To describe the idea....four posts 10" tall solidly posted at corners. Bungee cords running through top of each post and connected under 14"X14" platform causing it to be suspended between posts. Turntable sits on suspended platform. Works great...cheap too....Tried shorter bungees but too short and all benefits evaporate. Turntable has been decoupled from sub influences too it appears since sound was so much clearer. Ortofon Blue...Klipsch Lascala,,,u-turn Orbit acrylic platter...
If you want pics please email me at donallenchilds @yahoo.com. I'm very interested whether or not it will make a similar improvement for others systems.  If you think about it, what makes a cheap turntable different from audiophile ones? Tone arm is better at isolating vibration, so is platter, plinth, turntable base, ...its primarily about giving the stylus a chance to track without interference. This does that. Makes a U-turn Orbit into a much better animal. very amazed at improvement 
Bungee cords are like any other type of spring, they can be used to isolate any and all components. The trick is to match the spring rate of the bungee cords with the mass of the component, you know, like any other mass on spring. Ideally you want to obtain a smooth very low frequency up and down motion when pushing on the component. 
Right. And it needs to be tuned according to both the frequency and amplitude of the vibration you're trying to filter out, as well as the mass and fundamental resonance of the device you're using. 

Normally the #1 most important source of vibration is the component itself. Even amps and DACs with no moving parts generate significant vibrations. Acoustic vibration is usually #2 with vibrations from floors a distant #3, unless of course you live in a yurt, in which case its #1 with a bullet.

If the OP wants to take this to the next level, adding mass will further lower the fundamental resonant frequency of the rack with a further increase in bass response and imaging. But again, this will require tuning to find the right combination of mass and bungee cords.

Essentially what you are doing allears4u is building a giant Linn type suspension for your turntable. 

millercarbon
Right. And it needs to be tuned according to both the frequency and amplitude of the vibration you’re trying to filter out, as well as the mass and fundamental resonance of the device you’re using.

>>>>Huh? No it doesn’t.
That's why I say I got lucky. Without any special knowledge, out of abject desperation, I built this suspended platform. I realized just how lucky after I tried to replicate it in a different form. Footfall problems even got magnified in one attempt. Lost clarity.  Once right, the platform actual will slightly swing or sway after I place record and stylus. One thing that still stuns me is how sound stage size added a quarter in size above the one I had grown accustomed to before. And I do mean, above, that is, audibly higher in the room. AND, the whole is less tube like and natural.  I think my Sunfire sub HRS-10 was really blurring everything. 
Clever and effective. The best frequency is between 2 and 3 Hz. You can tune it by adding mass. If you get it right you should be able to jump up and down indiscriminately. The improvement in sound is also no surprise. If you get a SOTA , SME or Basis you can put the turntable anywhere on anything and it will do just fine. IMHO an isolated turntable is a must.
 
As for mass...a 2 pound record weight rides along to keep things solid. Deer skin platter mat. Cambridge Audio phono pre amp. The analog fever on the cheap. Leveling is perfect due to easily adjustable toggles on mid weight bungees through posts.  =Found out the hard way, the bungees must not touch plinth. Added Iso feet under free standing frame.   
@allears4u

Is it possible to see a photo to see and understand the structure as it is made?
For pics please send to my email at : [email protected] Sorry for inconvenience....I'll respond with pics from there....sorry again...thanks for interest....I'd like to see if others will experience sound improvements like I did. Easy to build, once you get the lengths of bungees, distances,  and all that stuff right.