panzerholz plinth?
- Thread starter karma67
- Start date
Joe
pfm Member
.
I'm still puzzling over this ....
but then again, I think you are all dancing around the subject.
I'm still puzzling over this ....
but then again, I think you are all dancing around the subject.
misterdog
Not the canine kind
Could be the Absinthe.
Helen Bach
if it ain't Baroque ...
Hi Jamie, Panzerholz is an excellent material, if you can get hold of a bit, and machine it.
With regards to your present plinth, aluminium and mdf. The obvious problem to me is the thickness of the aluminium. Bending stiffness will be high, which will probably affect damping. I don't have my two layer spreadsheets to hand, but with a three layer (Al/mdf/Al) laminate, it suggests using a much thinner layer of aluminium, 1mm is OK, getting progressively worse with increasing thickness, which may be counter intuitive.
With 5mm of aluminium, the bending stiffness is high, not what we want! If fact, the fundamental resonance frequency and critical frequency are nearly the same, meaning that any benefit from the high mass is negated, and you may hear sound from the plinth above those frequencies.
So, either reduce the aluminium thickness down to 1mm, or choose a different material would be my advice.
Joe
pfm Member
karma67
pfm Member
helen i was talking about the tonearm board not the turntable plinth,the board is only 125mm square and is bolted to the plinth,i got a price for an off cut of panzerholz but its more than im willing to pay at the moment,im also waiting for a sample of permali which i believe is basically the same thing,the other option is using a block of ebony.
what are your thoughts?
Helen Bach
if it ain't Baroque ...
Hi Jamie,
yes, Permali is very similar to Panzerholz, and may be even better at lower frequencies. If you can get a piece of Permali the size you require, it will be more than adequate for the job. I believe that the people who make Permali make the wood boards that go under F1 racing cars!
I did a quick test on an ebony block, and it was less than useless, about the same damping factor as mdf and slate (it is very hard, read stiff!). It is about the same as some of the worst hard woods. Which is a pity, as in most cases where the wood 'looks' nice, it would measure quite poorly.
yes, Permali is very similar to Panzerholz, and may be even better at lower frequencies. If you can get a piece of Permali the size you require, it will be more than adequate for the job. I believe that the people who make Permali make the wood boards that go under F1 racing cars!
I did a quick test on an ebony block, and it was less than useless, about the same damping factor as mdf and slate (it is very hard, read stiff!). It is about the same as some of the worst hard woods. Which is a pity, as in most cases where the wood 'looks' nice, it would measure quite poorly.
Chops54
pfm Member
Thats a bit of a tease.... more information is needed ..... and pictures.
Ok I'll post some pics of my current turntable tomorrow. I built it around a Clearaudio bearing and platter and even though I modded the platter by bolting a lump of aluminium to it it's not really a true home build is it so I decided to make my own bearing, hub and platter. I didn't have a lot of spare cash but the chap next door let me have some 25mm acrylic and I bonded three sheets together and machined it up. I got stuck with the bearing and the project stalled. The thing is I'm not over keen on a fully floating bearing preferring to have a small amount of weight sitting on the shaft most likely through a ball bearing and thrust plate. I couldn't work it out but after looking at your removeable spindle it gave me the idea that if the spindle was threaded into the top of the platter or bearing then it could be adjusted to take a small amount of weight off the maglev. Does that make sense? I have another platter made out of paxolin somewhere too. Out of interest how much does a lump of aluminium like that needed to make your turntable cost?
Joe
pfm Member
Chops
That sounds like you have a fun project on the go there.
The aluminium billet that I bought was 320x90 ( to allow for machining ) and was bought from an eBay supplier for £120 delivered.
I maybe could have found it locally for less but, to be honest, couldn't be bothered to personally visit all the stock holders around here to try and shave a few quid off that price.
I don't know if it is of any interest to folk contemplating building a similar deck but the costs of my deck were roughly thus...
Panzerholz.. £ 90
Aluminium, stainless steel, Oilite, tungsten carbide bar and brass £310.. I have most of the brass and the Oilite stock still left over.
Labour to machine all the metal, to cnc the plinth and a small amount of finishing to various bits .. £570
Bear in mind that ,in a sense , I did none of the work myself. You can save a lot on the labour if you can do it yourself.
That sounds like you have a fun project on the go there.
The aluminium billet that I bought was 320x90 ( to allow for machining ) and was bought from an eBay supplier for £120 delivered.
I maybe could have found it locally for less but, to be honest, couldn't be bothered to personally visit all the stock holders around here to try and shave a few quid off that price.
I don't know if it is of any interest to folk contemplating building a similar deck but the costs of my deck were roughly thus...
Panzerholz.. £ 90
Aluminium, stainless steel, Oilite, tungsten carbide bar and brass £310.. I have most of the brass and the Oilite stock still left over.
Labour to machine all the metal, to cnc the plinth and a small amount of finishing to various bits .. £570
Bear in mind that ,in a sense , I did none of the work myself. You can save a lot on the labour if you can do it yourself.
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Joe
pfm Member
Joe
pfm Member
*
I can sort you out on the size but the thickness is 25mm.... thats what it comes in. Do you have machining facilities?... reducing a 125x125 mm block from 25mm might be a bit of a sod?
I will talk to Misterdog and see what we can do.
I can sort you out on the size but the thickness is 25mm.... thats what it comes in. Do you have machining facilities?... reducing a 125x125 mm block from 25mm might be a bit of a sod?
I will talk to Misterdog and see what we can do.
Joe
pfm Member
*
I am trying to leave this conversation between yourself and Hell'n'Back but the design you describe I am struggling to picture.
If your armboard has those proportions and is bolted to your plinth would it not mainly have the sonic properties of the plinth?
I am trying to leave this conversation between yourself and Hell'n'Back but the design you describe I am struggling to picture.
If your armboard has those proportions and is bolted to your plinth would it not mainly have the sonic properties of the plinth?
Chops54
pfm Member
I have on a Lenco and I preferred it partial. Tbh, I'm not that sure either way but to have the ability to do either is a real bonus.