DIY turntable isolation

Yeah! Concrete floors are the best for turntables!

 

This brings up an important point... There are two different but related things being discussed in this thread, and it's causing some confusion. One is how to isolate a turntable from footfalls, and then there is how to filter airborne feedback vibrations and/or internal vibrations (from the motor, platter, etc.). That distinction needs to be pointed out!

 

Keep in mind that mass loading a suspended system is completely different than mass loading a non suspended system.

 

Touche! A case in point is the Linn LP12, Linn recommend a very light rigid surface for it. I had my Linn on a wall shelf and couldn't believe the difference when I put it on its own dedicated light structure on the floor!

JG

 

Correct!

 

OK, can someone explain the differences for those of us who don't know?

 

I agree!
The other bit to add is what roll the turntable mat plays / can play for minimizing acoustic vibration.

 

Thanks again.

The blocks came and in my setup they work a lot better then the inner tube did. I could not have pointed to anything wrong with the inner tube but the blocks are far better at isolating my TT from footfalls. I always assumed it was something I had to deal with in my 110+ year old home.

 

Where did you buy your Dust cover? I have a scout 1.1 incoming and would like to get a dust cover for it.

 

Thanks to Drew769 for the vibration pad info!

Just a heads-up...
I just now found and ordered those same isolation blocks over at SupplyHouse.com for 27 cents each. They offer a much better shipping rate of $4.95 compared to WestSideWholesale's $8.95 rate.
I ordered 24 to have extras for future damping endeavors.
http://www.supplyhouse.com/DiversiTech-MP-2C-Rubber-Cork-Anti-Vibration-Pad-2-x-2-x-7-8

 

Glad to help! Just paying it forward, as someone recommended those blocks to me!

 

I bought it from Norm at Stereosquares. The advertise on Audiogon..just search VPI and you'll see their ads.

 

Ron, I came across this post and joined this forum because of your post. I would really love to see inside this box (or see drawings, etc.) and hear more of your thoughts on what lead you to this solution. Especially what you might have tried and discarded along the way, Based on what minimal research I have done on the SLM1A, this looks like one of the most economical solutions I have seen for something along these lines. Definately sound engineering at a reasonable price.

thanks,
Rob

 

Rob,

I've left you a private message. Please contact me if you are still interested in this project. If so, I'll try to find my notes.

Ron

 

Just a non-technical comment, my original AR turntables (had two of them) were amazing in feedback rejection and tight focus of the bass and midrange. My first AR was located on a bookshelf adjacent to the right speaker. With the system cranked up, there was never any feedback. The AR was also exceptional in footfall isolation, but only the first one I owned, not the second one. The bounce rate was slow on the first, and dampened by simple foam inserts within each spring. The second AR (the same XA model) had a faster bounce rate, and did not reject a heavy footfall.

The original AR mat was extremely soft and compressible to the touch and with a slow rebound. I believe the AR mat was a major contributor in the performance of the AR as a system. I believe likewise, the mat tended to dampen vinyl resonances. The original mats didn't last long. They decomposed (turned to gel) after about 5 years, so none of them have survived the decades.

Steve VK

 

Missed your post until today.

Unfortunately I'm either too new to reply to pm's, or too dense Anyway I would like to see your notes if I can figure out how to get them.

Either way I'm trying to sort some issues with a new table I recently bought but was damaged in the mail, so frustrated by that.

 

Rob,

If you PM your email address to me, I'll send you pdf copies of whatever notes I have.

Ron

 

Thanks, will do, I think I have to post more to be allowed more access.

On another note: Has anyone every made or seen a isolation platform out of Delrin? I see some modern tables are being made with this material, not something I am familiar with in turntables.

 

Hi Blakep,

Could you tell me the density of the foam you used in the constrained layer approach? Do you feel 3mm thickness is the best thickness for a 140 - 180 kg/m(3) neoprene foam?

I'm looking to produce my own with that density and would appreciate your thoughts. The price difference is negligible between 3,4,5,6 & 8mm.

Would it be possible to see a photo or two of your shelf?

Thanks in advance

 

Hi Rob:

I'm sorry I cannot tell you the density of the foam. I ended up sourcing it from a custom upholsterer that was local to to me-it was dirt cheap, I think he only charged me about $10 for it. I do recall it being very similar in nature to the material used in wetsuits and pretty close to the same thickness as a wet suit. Possibly a bit more dense than a wet suit. In this application my gut feeling is that thinner (or 3 mm) would actually be better but that's just speculation on my part.

This shelf sits deep into my Target wall shelf so without taking my table down & removing it from the shelf (sorry ) you really cannot see much of it. And it's a total pain in the A$$ to post pictures to this forum now.

But this type of shelf is about as simple as you can get. Two solid layers supportive enough to not flex under the weight of your table with the neoprene sheet between. I was going to clamp & glue everything together with adhesive (which I still have kicking around) but never got around to doing so as the results were so good as is.

 

My WTA has squash ball feet ( standard equipment) resting on a maple block that previously served as an amp stand. This block has sharp brass cones that rest on 4 shallow brass footers that in turn reside on the top shelf of my SolidSteel rack. Concrete floor so no issues with vibration, footfalls etc

 

I never heard a response to the patrickd's question about how one mass loads a suspended turntable versus a nonsuspended turntable.

 

On my AR turntable, the T-bar has several pounds of additional mass added (solid pieces of metal were carefully fused), and more robust Linn springs were installed to support the weight. There was also additional mass added to the pulley.

The work was done by Marc Morin of Columbus, OH, who specializes in upgrading AR turntables.

 

This looks like the simplest and easiest solution I've seen....

 

Hey. Ok I purchased some Symposium Acoustic platforms for my McIntosh gear. IDK, they look nice lol; not really sure I hear any difference than what they were on BUT strangely I am getting big time noise from the TT. This is supposed to eliminate it. I have a VPI Classic Signature.

Ultra Platform

Not using the couplers here as its recommended to use the Signature feet that VPI has directly on the platform. But the other day I was playing some records and playing it loud like normal But it sounded like someone turned my subwoofers that are built in my towers all the way to max. Like a tug boat was in the room. BAD. BTW , my gear is across the room from the powered GoldenEar Triton Ones.

So I thought at first that maybe its time to lube up the VPI. Had to order the synthetic oil for under the platter from amazon (thank you Mark-VPI) and got the 40W oil for the motor. When that comes in I can lube it.

But for now they told me to take the TT off the new platform and try it again. I did. Problem solved. So ****. Pretty expensive platform. Suggestions on how I can still use this Ultra platform? I can cut thick felt pads to go under the Signature feet?

Other ideas?