I need a little help with springs

[Wakefield Turntables]

I'm looking at solutions to limit vibration into my Garrard 301 plinth. I've been offered 4 pretty large springs. The idea being to simply sit the Garrard 301 plinth on the springs. Is this is good, bad, or pointless idea? I understand several decks in the past have incorperated spring suspension for the same idea but I'm not so sure about externally mounting a plinth on the springs themselves.

[MCRU]

why not just use 3-4 slabs of your favourite material dude, sorbothane?

[CageyH]

As in a mass/spring damper?
I think that tt needs to be tuned to the frequencies you want to eliminate, so it's not straight forward.

[Wakefield Turntables]

why not just use 3-4 slabs of your favourite material dude, sorbothane?

Dave, already thought about it. It would probably dampen the deck too much. I tried this with the 1210 and HATED the results, but thanks anyway.

As in a mass/spring damper?
I think that tt needs to be tuned to the frequencies you want to eliminate, so it's not straight forward.

Yep, thought about this as well, your correct, it's not as straight forward as I thought.

[lurcher]

Dave, already thought about it. It would probably dampen the deck too much. I tried this with the 1210 and HATED the results, but thanks anyway.

Not sure what sort of plinth you have, but how about a two stage setup. use a massive slab of slate or some other high mass item, isolate that from the support with sorbothane, then point couple the 301 to that layer.

As you say, it depends on the frequencies you are trying to deal with, below some frequency, it might be better to just let the entire system move together. I would guess the trick is to make sure the support resonances are not related to the arm cartridge ones.

Further thoughts, I am not sure you can expect a 301 to behave in any way like a 1210 with respect to how it responds to supports.

[Wakefield Turntables]

Not sure what sort of plinth you have, but how about a two stage setup. use a massive slab of slate or some other high mass item, isolate that from the support with sorbothane, then point couple the 301 to that layer.

As you say, it depends on the frequencies you are trying to deal with, below some frequency, it might be better to just let the entire system move together. I would guess the trick is to make sure the support resonances are not related to the arm cartridge ones.

Further thoughts, I am not sure you can expect a 301 to behave in any way like a 1210 with respect to how it responds to supports.

Nick,

Hi! I dont expect the 1210 to work like a 301, I just dont want the 301 to be dampened and sounding crap Funnily enough I have some old granite chopping boards (but I've heard these resonate) and shit loads of sorbothane so I could try this I suppose. The plinth incidently is 90mm birch ply.

[sq225917]

Weigh the deck, and weigh the plinth, then its time to do some maths to work out how much deflection you want and at what frequency.

[freem]

Have a look at sonicdesigns.co.uk and also possibly speak to Bob at rjcaudio.co.uk
I have two of his Hush platforms, one under my Techie, and they work a treat. He uses some form of tuned suspension and is also a Garrard fan having built plinths for them utilising his suspension system.
There is a review of a Hush platform with the Techie on HiFi Pig.

Hope this helps.

[Wakefield Turntables]

Weigh the deck, and weigh the plinth, then its time to do some maths to work out how much deflection you want and at what frequency.

Oi! What you doin answerin posts on threads, get back to building that phonostage !!!! Hi, Si, how you doin. Thanks for the info, can you enlighten me a little by sending me a PM or reply back to the thread with regards how this works?


[QUOTE=freem;520187]Have a look at sonicdesigns.co.uk and also possibly speak to Bob at rjcaudio.co.uk
I have two of his Hush platforms, one under my Techie, and they work a treat. He uses some form of tuned suspension and is also a Garrard fan having built plinths for them utilising his suspension system.
There is a review of a Hush platform with the Techie on HiFi Pig.

Hope this helps.[/QUOTE

Thanks for the heads up, will do a little reading tonight when I get chance.

[Oldpinkman]

As you say, it depends on the frequencies you are trying to deal with, below some frequency, it might be better to just let the entire system move together. I would guess the trick is to make sure the support resonances are not related to the arm cartridge ones.

I believe that is the principal used in suspended sub-chassis design. It also wants to be out of the audio frequency. Since you are unlikely to build a system with a resonant frequency above 20Khz you are left targetting 4-5 Hz as the ideal. Or so I am told.