Help in isolating a TT with spring suspension.

It's not about what you put under it, but about what you put it on ;-) And even if your "rack" is reasonably sturdy, the floor structure under the rack is probably what's bouncing (it's not a concrete slab is it!)

I bet even an un-sprung TT would have trouble in that situation, and what you're going to need is a wall shelf for the TT. Target's shelf ($179 at AudioAdvisor) is probably the most popular, and you can see it here http://www.audioadvisor.com/products.asp?dept=214

IMO, even the best TT stand sitting on a concrete slab can't beat a PROPERLY MOUNTED wall shelf.

It's not about what you put under it, but about what you put it on ;-) And even if your "rack" is reasonably sturdy, the floor structure under the rack is probably what's bouncing (it's not a concrete slab is it!)

Yes, I have an old house and my floors are not that good, but I've had other TT's that were not nearly this bad.

A wall mounted rack would be nice but it wouldn't work with the way my room is set up, and I really don't have the room for it. Speaking of concrete slabs, would putting a heavy flat piece of slate or stone of some kind help?

Thanks for the info.

It's not about what you put under it, but about what you put it on ;-) And even if your "rack" is reasonably sturdy, the floor structure under the rack is probably what's bouncing (it's not a concrete slab is it!)

Yes, I have an old house and my floors are not that good, but I've had other TT's that were not nearly this bad.

A wall mounted rack would be nice but I don't think it would work with the way my room is set up. Speaking of concrete slabs, would putting a heavy flat piece of slate or stone of some kind help?

Thanks for the info.

Drill a hole in the cieling and put a large heavy flywheel on a bearing that will accept a cast titanium rod that has a braek away split tackle ring in it. Put the record on platter then jack up the stand until you can attach the free to rotate, superstrong, titanium rod and flywhell. The super upstairs flywheel rests on a track which is a semi enclused u channel follied with very lightwieght oil . Cordinate a 1 hp electrical motor to drive that wheel in synchrony from the platters own small motor. Have the rack decouple from the flor though vibration isloation industrial grommets make sure all is on a laser leveled angle, taking absolute pendulum striaght fall 0 = the table flywheel assembly as your reference and you are ready to go.
Or just place your current rack on a very heavy steel reiforced thick wooden walled sandbox put an attractive wooden slab as the top layer and you could even get some real massive spikes for rack footers. This mass will abate your footfall and will not allow spinged tension to release put the box on a 3m cork mat with neoprene then a layer of sorbothan sheet then another layer of cork neoprene . Although not fashoinable there is dust free lead micro shot available to fill the sandbox that's the sand and what I mean by mass. Make sur you get the ordinances licenses and an architect to sign of on iether choice.
Add up the cost and realize the shelf is much much cheaper and as effective. With your savings buy a really nice table and get into vinyl.

Or you could try an Arcici Airhead. I had one under my Weel Tempered Reference for many years and it worked well. Basically it is a wooden platform floated on three inner tubes.