what suspension?

[davecooper]

I have finally got around to planning a turntable build that has been lurking in the back of my mind for years. The mechanicals are basically Rega and the arm is Audio technica. The plan is to build these into a plinth formed from a solid block of oak that I have had sitting around for years. The plan is to fabricate an aluminium/MDF laminated sub chassis to take the arm and sub platter/bearing assembly. This will then sit on some form of three point suspension in a recess cut into the top of the plinth. The motor will be mounted off the sub chassis. The plan is that the majority of the sub chassis is hidden by the platter with just a small extension for the arm visible. This is to maximise the wood showing on the top. The main platter will be a newly made deep section affair, the idea being to give a similar look to that of some early japanese turntables. Now to my question, what are my options for the suspension. I'm sure there are people out there have done much experimentation with various materials over the years and have some recommendations. I do not need any levelling system for the sub chassis as the whole plinth will sit on Microsorber adjustable feet and I will shim the suspension to bring the sub chassis flush with the surrounding plinth material.

[davecooper]

I have just realised that my terminology is a bit awry in my post above. It won't be a suspended sub chassis but one sitting on a three point resilient mounting system. It is the absorber material on which the subchassis will sit that I am asking for advice on.

[wjlamp]

Originally Posted by davecooper

I have just realised that my terminology is a bit awry in my post above. It won't be a suspended sub chassis but one sitting on a three point resilient mounting system. It is the absorber material on which the subchassis will sit that I am asking for advice on.

No easy answer.
The only way,is to pick several samples of various materials,not only absorbing.Try them 'til you find the one that suits you.Just for the record,try some rubber,felt,acrylic,metal cones,glass balls,pumice stone,samples of wood.
Each one has certain qualities,good and bad for the situation.But stay away from another springy absorber.

B.L

[davecooper]

Thanks for that, I guess experimentation is the way to go. Is the wise thinking that a cone is probably the best shape to use? These would be very easy to employ in my design

[wjlamp]

Originally Posted by davecooper

Thanks for that, I guess experimentation is the way to go. Is the wise thinking that a cone is probably the best shape to use? These would be very easy to employ in my design

Yes and no. It depends on the synergy of the individual materials to each other.No hard and fast rules apply.Spend some time,enjoy the ride,and you'll be there

btw a stethoscope, like the ones used for measuring blood pressure,works wonders here.
B.L.

[davecooper]

Has anyone ever experimented with silicone sealant for any form of suspension?

[wjlamp]

Originally Posted by davecooper

Has anyone ever experimented with silicone sealant for any form of suspension?

It's an option.I've tried that too,some time ago.But use it in moderation. Just make sure that you use as much,up to the limit of not being springy.


B.L.

[Xoc1]

Sorbothane rubber feet are one solution.
It forms a self dampening suspension when used in compression.
A quick google search produces a lot of relevant links.
Various sizes & grades available on ebay.
I think that my Townsend Rock turntable uses 3 of these as feet.
(The prototype if I remember correctly used super slow squash balls, cut in half?)

[Jacques Merde]

Originally Posted by davecooper

Has anyone ever experimented with silicone sealant for any form of suspension?

I am using some modified grommets from EAR specialty composites.

[SGregory]

I use a 2 part silicone product called Dragon Skin. Used by the hollywood types for effects. You can get several different viscosity and sets in about 1-2 hours. The stuff I have is close (but not quite) to sorbothane. You do have to experiement on how much to use though as was stated above.