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Post by rexton on Jan 3, 2021 11:56:05 GMT
I've started looking into redesigning my Garrard 301 plinth. I have one simple question and would just like a consensus of opinion. My objective is to limit vibration getting into the headshell. My intentions as stated in the thread title are to decople the motor from the Garrard 301 and use a seperate arm pod. What it be fair to say that by using both techniques, it should minimise the chances of vibration getting into the cartridge? Sounds like the answer is pretty obvious but I would like comments and input from you guys.
Many thanks, Andy.
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Post by karma67 on Jan 3, 2021 12:47:20 GMT
I've started looking into redesigning my Garrard 301 plinth. I have one simple question and would just like a consensus of opinion. My objective is to limit vibration getting into the headshell. My intentions as stated in the thread title are to decople the motor from the Garrard 301 and use a seperate arm pod. What it be fair to say that by using both techniques, it should maximise the chances of vibration getting into the cartridge? Sounds like the answer is pretty obvious but I would like comments and input from you guys. Many thanks, Andy. why do you want to maximise the chances of vibration getting to the cartridge? lol |
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Post by macca on Jan 3, 2021 13:15:50 GMT
Depends on the frequency of the vibrations - what works to isolate from mid/high frequency vibration won't work on low frequency vibration and vice-versa.
And airborne vibration will be unchanged regardless of what isolation methods you use.
All you will do is change the sound of the TT rather than improve it in any objective sense, you might prefer the different sound but then you might not.
It's an intractable problem really. how do you isolate a device that is designed to pick up vibrations, from vibrations? And the answer is that you can't. All you can do is shift the variables around a bit.
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Post by rexton on Jan 3, 2021 16:22:20 GMT
why do you want to maximise the chances of vibration getting to the cartridge? lol Corrected, thanks Jamie. |
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Post by rexton on Jan 3, 2021 16:33:45 GMT
Depends on the frequency of the vibrations - what works to isolate from mid/high frequency vibration won't work on low frequency vibration and vice-versa. And airborne vibration will be unchanged regardless of what isolation methods you use. All you will do is change the sound of the TT rather than improve it in any objective sense, you might prefer the different sound but then you might not. It's an intractable problem really. how do you isolate a device that is designed to pick up vibrations, from vibrations? And the answer is that you can't. All you can do is shift the variables around a bit. Thanks Macca, al very valid points and that why I posted my thread. I just wanted some thoughts and ideas on the topic. |
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Post by jimbo on Jan 3, 2021 17:41:17 GMT
Andy I found the biggest improvement by far was to isolate the turntable from vibration as effectively as possible both structural and airborne. I had a huge uplift in SQ in every respect from vibration reduction.
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Post by rexton on Jan 3, 2021 18:14:14 GMT
Andy I found the biggest improvement by far was to isolate the turntable from vibration as effectively as possible both structural and airborne. I had a huge uplift in SQ in every respect from vibration reduction. Jim, I've already started going down that route, here's what's been done and my future game plan.
Idler wheel, motor and bearing completely rebuilt by myself and then checked by Martin Bastin - it passed.
New motor suspension springs and damping rubbers installed.
Damping rings around the platter
New panzerholz SME tonearm mount, minimised to hopefully optimal thickness.
New damping rubbers for the SME 3012 tonearm mount onto the panzerholz mount.
New isolation grommets for the mounting threads inside the 301.
The 301 sits on a spiked Bamboo isolation board which offers some protection from external vibrations from other components on my rack.
My Paradise / Pre and Power amp all sit on Bamboo + Sorbothane isolation boards in a bid to try and isolate vibrations getting up-to the 301.
The modular approach is going to encompass several ideas mainly trying to isolate vibration from external components on my rack whilst further minimising vibration from the 301 itself.
1. Skeletal plinth for the 301 made from optimally thick panzerholz or Permali.
2. Seperate tonearm pods probably going to be high mass then actual arm mounted on Permali or Panzerholz
3. Replace the isolation board from Bamboo to Permali.
4. Decouple the motor from the 301.
5. Replace each shelf on my rack with one made from Permali to give additional damping.
6. Look at damping the chassis from my accelerometer experiments.
7. Look in ceramic head shells.
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Post by macca on Jan 3, 2021 18:15:54 GMT
How can you isolate from airborne vibration? The deck would need to be in a different room from the speakers, ideally in a vacuum chamber.
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Post by rexton on Jan 3, 2021 19:00:11 GMT
How can you isolate from airborne vibration? The deck would need to be in a different room from the speakers, ideally in a vacuum chamber. No idea, maybe the plinth could be designed a specific shape to disrupt anything airbourne? This is pure conjecture on my thinking. |
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Post by macca on Jan 3, 2021 20:41:05 GMT
Given the number of turntables out there that cost crazy money and the length of time turntables have been developed over (100 years?) I'd guess anything that might work has been tried at least once. But I can't think of any way of stopping airborne vibrations hitting the most sensitive area i.e the arm and cartridge.
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Post by antonio on Jan 4, 2021 1:09:28 GMT
Would covering the tt with a perspex lid do it?
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Post by electronumpty on Jan 4, 2021 7:26:43 GMT
Given the number of turntables out there that cost crazy money and the length of time turntables have been developed over (100 years?) I'd guess anything that might work has been tried at least once. But I can't think of any way of stopping airborne vibrations hitting the most sensitive area i.e the arm and cartridge. Play the tt in a vacuum ? |
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Post by jandl100 on Jan 4, 2021 20:17:32 GMT
Would covering the tt with a perspex lid do it? Generally, covers screw up the sound, I think, by adding sources of resonance. |
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Post by jimbo on Jan 4, 2021 20:52:01 GMT
How can you isolate from airborne vibration? The deck would need to be in a different room from the speakers, ideally in a vacuum chamber. Airborne vibration would surely be dependent on how close the turntable was to the speakers? |
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Post by jimbo on Jan 4, 2021 20:54:26 GMT
Would covering the tt with a perspex lid do it? Generally, covers screw up the sound, I think, by adding sources of resonance. I think your right there Jerry, they tend to act as a sound board, transmitting vibration back down to the turntable plinth. |
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Post by sq225917 on Jan 4, 2021 20:58:11 GMT
A nice chunk of 2x6" on its edge with felt footed outriggers between speakers and deck.
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Post by macca on Jan 4, 2021 21:56:32 GMT
How can you isolate from airborne vibration? The deck would need to be in a different room from the speakers, ideally in a vacuum chamber. Airborne vibration would surely be dependent on how close the turntable was to the speakers? Yes, stronger if closer of course. But even if they are a good distance away the stylus will pick it up, the sensitivity of the cartridge to vibration at all frequencies is very high, it has to be or vinyl wouldn't work very well at all. On the plus side the reverb created by the bass frequencies does enhance perceived sound quality as long as you don't get the TT too close to a speaker. Still probably best to site the TT in a bass null if possible though which is why sticking it in corner is not really optimal. |
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