Isolation for turntables

I'm looking for some ideas on how to keep my turntable on the straight and narrow. My Oracle Delphi IV/SME345/Grado Reference is not in the ideal environment. I had a custom oak stand built for my gear and certainly blends well with the decor. Trouble is, my listening room has an oak strip hardwood floor, slightest footsteps makes the cartridge jump. Ouch. I bought a Townshend Seismic Sink HD and slipped it under the 'table, no real improvement. So, I'm going to sell the Sink and get something else, question is, what can I use to keep my rig from bouncing around? Thanks in advance for any and all suggestions, Jeff
I don't know if this is possible in your particular situation, but I bought a wall mounted audio shelf. I had the same problem, and now it never ever skips. It's not very fancy, but it does the trick. It's a steel frame (black) with a black plank of wood resting on small spikes. If you want additional isolation, I suppose you could always put the Townsend thingy on the shelf.
Another method is to put a supporting concrete pile under your house directly under the turntable - although I concede this is not always practical. Since the Oracle is sprung, then any additional compliant isolation will cause sonic degradation through creating nodes between the resonant frequencies of the two systems. Another method would be to find where the floor has solid supports, and put the turntable on top of one, or put it on a rigid plank that spans from one to another of the supports.
Two solutions, wall mount it, which is the easiest. If you have a crawl space or basement under the floor (joist and frame construction) it would't hurt to beef up the floor under the turntable. Those joists need reinforcement with a couple of piers and stringers running perpendicular to the joists or columns and stringers if a basement. This may not be practical in the case of a basement. Who wants an extra column or 2 in the middle of their basement? Without knowing all the specifics, this information is general but, you get the idea, your floor needs more support down under.
I went wild building a wall mount shelf for my P-25.I bought some heavy steel 18"long L brackets and bolted them to 2 2x4's which I then bolted to the wall.The bolts go through the wall to the outside where they are very tightly secured with nuts.On top of the brackets I placed 4 rubber grommets.On top of those a 16"x16" x1" MDF shelf rests and on top of that a Bright Star Audio Big Rock #4.Never had a problem amd the sound improvement was very noticeable.
Hi Jeff, First, you must learn to properly adjust your Delphi's suspension.It is without doubt, the finest spring suspension turnatble evr designed in terms of isolation from outside disturbances.You should be able to host WWF tag team matches in your listening room without missing a beat.When it's done right, the platter will not shimmy or sway at all but rather operate in a pure pistonic motion.You should be able to tap firmly on the clamp and it will settle in 1-2 cycles to an even, slow bounce at 3-5 cycles/sec and die away.Check to see that the tonearm cable is not fouling in any way. second,the best means of siting would be a lightweight,rigid wall support like the Target VW1 or older TT1 and original Sound Organisation wall mounts.Second best would be a similarly principled Target,Standesign or Sound Org floor stand.High mass and heavy weight will store energy and re-release it back into the system as well as energise supsended flooring like a tramopline.You want a low mass design so that vibrations dissipate quickly and thus intrude less into the music.A small amount of blu-tac on the lower portion of the legs is all you need for damping.Avoid sand and lead filling of the legs like the plague as it will slow and muddy the sound.
Thanks for the inputs all. My setup just doesn't allow for a dedicated 'table stand, whether it be floor or wall mounted, just not enough room. Underneath the listening room, in the basement, is an unfinished furnace room. Based on these inputs, I'm thinking of crossbracing the floor joists, and putting in a telescopic steel column directly under the gear. As much as pouring a concrete pillar intrigues me, that may be going a little too far, people think I'm insane as it is when it comes to audio. I agree with Caterham, the 'table should be immune to pretty much anything, I'm fortunate in that I live less than 90 minutes from Oracle, Mr. Riendeau tweaked my Alexandria for me a while back, I think it's time for the Delphi to go in for a tune up. Any isolation base products I should consider as well? I'm using Bright Star bases under my pre and CDP, but doubt they'd be ideal for something as large and as heavy as a Delphi. Thanks again, Jeff
Okay.How about this?Your problem lies with the heavy cabinet, particularly as it is on the supended flooring.If you place 2 small wood blocks or feet at the bottom/rear of the cabinet and then rock it bacwards and attach it to the wall studs, you will have effectively turned it into a wall shelf and placed its mass onto the much more stable building structure rather than the springy flooring. Your next step would be to try a low mass tabletop isolation platform like the Target VF1, RATA(Russ Andrews) Torlyte, Cetech composite or one of the less expensive Symposium platforms(I don't much care for the ultra).These units are amoungst the most stable and musical means of decoupling and PROTECTING your deck from the energy storing, information smearing mass of the cabinet and probably the least intrusive and convenient.The Brightstars would be musical death to your Delphi, IMO. Best, Ken GreaterRanges/Neuance
A thing that works for us(Wifes idea) is to go to the local Hdwe store get some canister corks and place them under the feet. May work, may not, no great investment in time or money
get the thing set mkII will also take a WWF triple header and not flinch! i suggest you do it yourself or watch the set up so that you can do it in the future. assuming the table is currently set reasonably well all you need is the oracle paper jig to measure the tower distance from the acrylic base and spin the springs for best bounce uniformity. mine gets a tune up every 1 to 2 years and rarely needs anything but a precautionary oil change.
if you still aren't satisfied sell it to me Jeff