A Copernican View of the Turntable System
Dear Geoch - it was my intent for the next project to replace my solid aluminum armboard with a brass one and maybe add a panzerholtz tonearm plate on top. From your last post - do you feel this would be worth the expense and effort? Pictures of my setup were in my link in my last post. Appreciate any thoughts on this ? Cheers Chris |
Whilst Chris' Guide to making your own armpod is admirable, he appears to have concentrated on his ET parallel-tracking arm which I feel is different to the majority of pivoted arms? When I designed my armpod, I attempted to make it 'universal' in that it could accommodate all the vintage pivoted arms I could find and all the modern ones as well. The major differences between the vintage arms and the modern ones are most likely to be the fact that vintage arms have a bottom plug-in din phono cable which needs to enter the armpod. There is also the 'barrel' of the arm-base to accommodate the rising VTA mechanism and this varies in diameter for all arms. Some modern arms have this 'barrel' as well although their wiring usually exits the arm on top of the arm-base rather than under it. The largest diameter 'barrel' I could find was that of the Copperhead arm and a hole of 55mm diameter could accommodate that. I later found that the VTA barrel of the FR-66s arm was exactly 55mm diam so I'm not sure if this would easily fit? To accommodate all the different diameters of the arm bases available, an independent top-plate is used to 'attach' the arm to the pod. HERE |
Hi Chris, I think the decoupling offered by the wood plate is a very drastic solution, applied in desperate situations. My concern is about the strength & tightness of the surface that couples the arm pillar with the arm pod. I'm sure it works OK, but from the theoritical point of view, I would be more comfortable if you choose a more solid upper fixed point, in order to modify the ET arm pillar, as if it is one piece with the first block of the arm pod. Even if it is applied at the bottom* (the decoupling by wood), may not be necessary -in your case- considering there is a film of air in between the arm tube & the arm pillar. * Steel at the top plate, your own Al main block, Brass as a foundation or intermediate level. Especially the discs that rests the spikes must have great hardness. You can close the microscopic open moleculars between the metal surfaces simply by applying some silicone oil without bonding or bolts. Easy if you uplevel your main wood shelf with a second & preferably denser platform only for the TT and so, you will have the apparent hight for steel, brass & discs. Just a thought. |
Dear Geoch, 'life is to short' but it is never to late to learn. So as soon as I get my engeneering degree I will respond to the 'demping question'. Meanwhile you can direct your inquisitive mind to Vidmantas and ask any question about cork you like (Ruta@reed.lt or Vidmantas@reed.lt). I am very reluctant to ask Halcro to bring some 'light' in this 'mass matter' because I think that he is angry at me. Regards, |
As I understood the manual, any armboard will do. Part of it will be drilled onto the pod and the part with the larger hole where the tonearm mounts into would protrude beyond the dimensions of the pod itself. So, this would be different than Ct0517's set up but would still work for pivoted arms. In fact, that's what I did the first go around, but instead of using a metal foundation, I used red oak. My current pods are similar to Halcro's; but, sadly, far less cool looking. |
