Best isolating feet for turntable plinth?

[Ammonite Audio]

Stillpoints don't do themselves any favours by using the term 'isolation' since their products patently do not operate as isolators, but they are magnificent couplers when used between sensitive equipment such and turntables and a sensibly designed isolation platform. So, to answer your question, I do think that hard coupling feet should be placed between the bottom of your plinth and the isolation platform. Hardwood cones can be very good in that role and I would definitely not use any audiophile spike.

To expand on what I wrote earlier, a sensible support for a sensitive device such as a turntable should start by preventing ground and structure-borne vibration from passing up through the floor/walls etc and then into the equipment. That's why townshend platforms have springy feet but those feet are sensibly designed to be damped as much as is desirable, height adjustable and perhaps more importantly stable in use. Only springs can prevent truly low frequency energy from passing. Next, whatever vibration energy originating within the equipment (eg turntable) needs somewhere to go and here we are talking about noise from motor systems as well as that which is passed from the stylus, through the tonearm and into the plinth. A massy plinth can do a lot to absorb and disperse such vibration energy, but it's a good idea to provide a clear drain path from the plinth into another structure designed to absorb and disperse vibrations in an orderly fashion. That clear drain path is achieved by hard coupling the equipment to the supporting structure. That supporting structure needs to be a heavy platform (mass attracts energy) with sensibly designed damping and the Townshend platforms do that in a notably slimline form. So, in combination, a sensibly designed support platform will stop structure-borne vibrations from passing up to the equipment through walls, floors etc, while also providing a drain path for vibrations arising inside the equipment. None of this is rocket science but Townshend to offer a ready-made product that does work, and magnificently so in the case of turntables.

Thanks so far everyone - perhaps I should add a bit more detail to my OP.
I'm interested in isolation feet for a heavy, high mass wooden plinth that will house a Garrard 401. The reason is to de-couple and isolate the TT from environmental vibration e.g. the speakers, footsteps in the room, passing traffic, washing machines etc etc anything that could feedback into the TT, tonearm and cartridge. The plinth would be standing on a heavy MDF built-in sideboard that is attached to both the wall and floor (engineered wooden floor).

At the moment the plinth itself has no feet, which also leaves me the option to leave the feet off entirely and place the plinth flat directly onto an isolating platform like the Townshend. If I have understood correctly the increased surface area in contact with the platform can be of benefit to the isolation.
I could also attach some kind of coupling feet to the plinth e.g. spikes and then stand it on a platform. Or I could fit some isolating feet (eg Townshend pods) under the plinth and stand it directly on the sideboard, no platform.

Hugo - thanks for your thoughts, I've seen you recommend the Townshend platform elsewhere on here. (It's a pricey option for me as the TT + plinth will weigh-in over 35kg and the high-weight spec pods + platform is over £700 total.) Would you recommend placing the plinth directly onto the platform or putting some kind of hard feet or spikes inbetween? On the subject of looks, the platform is quite elegant, it's the pods I think look a bit fugly... unfortunately remind me of those cheap little pod speakers people attach to their laptops.
Thanks also for the clear info about the Stillpoints - I was not aware at all that they do in fact couple, and indeed as far as I could tell on their own website they seem to be claiming that the Stillpoints isolate.

[Vrajbasi]

The townshend platform does sound excellent under Garrards but as mentioned elsewhere I would use something in between the still points in my opinion sound a bit took forward and dont do too well with the garrard. I have also heard a RJC platform some years back that was made for the garrard that was a wooden box effectively with the townshend pod incorporated the sound was even better than the townshend platform it had a warmer earthy sound that suited the garrard well. Townshend does offer a good product available who cant quite go into the esoteric world of isolation like the Herzan and Minus k. Max townshend came up with a winner with the original seismic sink and has improved it over the years bringing sensible vibration control to a wider audience some of the more serious offerings cost thousands and yes they do work . I have a few townshend pods knocking around that I use when experimenting you would be most welcome to try them and see what you think. I also have other feet and bits and bobs in my draws.

[nickbaba]

Looks like Townshend is the recommendation then!

[nickbaba]

Thanks for the offer Nari - I might take you up on that once everything's assembled for the TT project. Still 4 or 5 weeks away.

[tlscapital]

Mmh ! I'm more of a "basic" phono boy when it comes to all that is not mechanical or electrical in my phono gear set-up. Inertia is crucial for the turntables to perform optimistically and this is achieved by the plinth mass. To isolate the turntable from vibrations, one either find "absorbent" material or "de-couple" it from transmitting build and material.

So I added mass to my solid beechwood plinth and fitted it with thick sorbothane feet. It's OK enough for me as I play my 45 rpms while the platter is revolving and drop and pick-up the stylus by hand and need so I need my turntable set high on a sturdy wall mounted cabinet. Mind you sorbothane material needs to be calculated to work optimistically.

Other effective, more complex and roomy turntable stand (for other use than 45 rpms play time) DIY design isolation turntable support is the ultra heavy "sand box" hung up in mid air on heavy duty building stands. Minimizing to almost nil point vibration transmission and providing inert enough through gravity support for the turntable. Impressive looking on top of it !

[nickbaba]

Further reading seems to suggest that a non-suspended TT won't need isolating feet and/or platform at all if its standing on a sturdy wall-mounted shelf?

[YNWaN]

Walls do not exist outside of vibration coupling issues and, in some cases, can be worse than the floor. Stud walls, or non-structure supporting walls, are actively worse than all but very poor floor surfaces and many speakers are capable of passing significant structure born vibration into even load supporting walls.

[Mikeandvan]

Walls do not exist outside of vibration coupling issues and, in some cases, can be worse than the floor. Stud walls, or non-structure supporting walls, are actively worse than all but very poor floor surfaces and many speakers are capable of passing significant structure born vibration into even load supporting walls.

Especially if you've a restaurants extractor fan stuck to your wall.

[Primalsea]

If you have a 401 I think that just mass dampening may be the way to go first, as you can knock something up very cheaply, just for appraisal. I didn't realise that your TT was a 401. They are quite heavy and the weight is not distributed evenly. My 401 sits in a slate plinth with plaster filled chromed tubes for legs. The cabinet is pine but completely lined with 18mm MDF inside. The whole lot is very heavy and there is no appreciable feedback from vibrations. I do have a solid floor with 20m oak boards. It may be a very different situation with a suspended floor though.

[nickbaba]

Ah - OK, so the wall won't save me!

I think I'll approach things in stages - the plinth itself will be large and heavy, and I'll fit it with solid feet (probably oak cones). So firstly I'll experiment with the dampening properties of the plinth itself, and from there experiment with different methods of isolating the TT if needed.