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401 to plinth interface - to dampen or not

naimnut

Deep in the Mines of Soul
I'm having a new plinth made for my 401. It's a variation on the Birch ply style. My question is whether I should have something between the chassis and the plinth. In the past I just had the chassis laying directly on the plinth. Sounded great.
But what do you all recommend?
Thanks, in advance, for any thoughts you'd like to share.
 
Experiment! Certainly try the Garrard fibre/rubber washers, also experiment with various bolt tightness (if you are using them). Whatever you do you’ll certainly hear it.
 
You have 4 small rubber "O" rings which sit between the mounting bolts and the plinth for damping. You should be more worried about motor vibration transmission into your platter and cartridge than anything else. Birch ply is ok but not the best damping factor. Have you considered decoupling your motor, lower the voltage running into motor, or changing the material your plinth is being made from? I've a feeling this thread could run some.....
 
I originally had my 301 straight to plinth, but a few years back I swapped to chassis>rubber washer>plinth>rubber washer>metal washer>nut, with nut lightly tightened I do feel this is better. I run my motor at 200v, speed adjust is central.
 
Yep loosening the mounting nuts/bolts is another tried/tested method of tweaking the Garrards. I run mine @ 220v.
 
Mmmmm. I don't think I have any rubber or fiber washers... at least not that came with my machine.
So it sounds like I will be improvising. I'll think of it as "suspension tuning". Kinda like tube rolling...;)
 
I call mine The Bulletproof 401 - it is bolted into a panzerholz plinth.

Wer, Panzerholz is known to have one of the best Damping factors but is quite expensive, especially trying to get it in the UK. Permali, as you probably know is a close match but less expensive.
 
Surely Pemali woild do equally well (i got my PH from a friend in Germany who had bought a whole sheet).
Pf course it wpuld be counterproductive to use damping washers if you have a plinth with a high dampung factor.
 
My question is whether I should have something between the chassis and the plinth.

A word of warning - some 401s will not sit flat without the rubber washers. Mine is a 1973/4 edition and there are protruding fixtures, only a MM or two in length, underneath the front panel that prevent the chassis from lying flat and level without the proper washers. I’ve seen earlier editions that will sit flat without washers, but best check.
 
It would be counterproductive to use damping washers if you have a plinth with a high dampung factor.

Wer, have you ever over damped a TT? I remember doing various experiments on my Lenco L75 and Technics 1210 and realising that you can over damp a turntable and then rob the passion and musicality of the presentation. I'm definity think damping to some extent is beneficial, it's just realising when that level occurs. I guess it's trial and error. I do have a Panzerholz tonearm mount on my 301 which worked really well.
 
I think it depends how flat your plynth is and how flat your 401 is, no way they will sit perfectly flat together.If you bolt up tight without washers in place it will distort the 401.I have mine bolted as loose as possible with no washers onto plywood,that sounded best to me, washers came second and very tight no washers was worse by quite a bit.
 


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