Armboard materials
- Thread starter matt j
- Start date
divedeepdog
pfm Member
No secret I like Corian. It seems to work for me. I’ve tried lots of materials, slate and aluminium not worth the agro for me ( I’m woodworker). Mdf is no-no, solid wood has been ok but you could write a book on timber variations. Perspex is ok, but more difficult to use and finish.
This is from an idler perspective though, they bring different problems to the party
This is from an idler perspective though, they bring different problems to the party
No secret I like Corian. It seems to work for me. I’ve tried lots of materials, slate and aluminium not worth the agro for me ( I’m woodworker). Mdf is no-no, solid wood has been ok but you could write a book on timber variations. Perspex is ok, but more difficult to use and finish.
This is from an idler perspective though, they bring different problems to the party
Interesting, Corian isn't something I'd considered. How does it tool do you need specific bits? Is it generally only available in worktop thicknesses or do they do thinner stuff?
Corian is a very heavily filled extruded polymer intended for use as working sufaces, including biology labs and such. I am unsure of the chemical nature of the binder polymer - it will be online somewhere.
It is probably filled with something like china clay - if you cut and polish the edges, you can see where the filler has settled towards the bottom of the extruded thickness. Apart from filler, it can have any number of dyes and pigments added, and even "glitter".
Because of the filler it will wear woodworking kit rather fast, but can be worked like wood. It can also be polished to a high gloss if it does not have glitter added (the glitter particles in the surface have "tails" from extrusion - a bit like a comet - so that when polished the glitter particles sit at one end of a minute furrow. That apart, it can still be polished).
If you check density online, it is high, due to the filler (the great majority of polymers have a density close to 1).
Used as intended, it comes in large sheets so that long runs of work surface can be installed with minimal requirements for joining.
If you can find someone (a professional installer) selling offcuts, it ought to save you £££££££
It is probably filled with something like china clay - if you cut and polish the edges, you can see where the filler has settled towards the bottom of the extruded thickness. Apart from filler, it can have any number of dyes and pigments added, and even "glitter".
Because of the filler it will wear woodworking kit rather fast, but can be worked like wood. It can also be polished to a high gloss if it does not have glitter added (the glitter particles in the surface have "tails" from extrusion - a bit like a comet - so that when polished the glitter particles sit at one end of a minute furrow. That apart, it can still be polished).
If you check density online, it is high, due to the filler (the great majority of polymers have a density close to 1).
Used as intended, it comes in large sheets so that long runs of work surface can be installed with minimal requirements for joining.
If you can find someone (a professional installer) selling offcuts, it ought to save you £££££££
martin clark
pinko bodger
Yep, 1.7g/cm or thereabouts. It's mostly methacrylate with aluminium hydroxide / trihydrates as filler. Tungsten carbide tooling preferred by pros. Many knock-offs abound - Formica Gloria, Hi-Macs as already mentioned, others. Sands easily, finish as nice as you like.
You'd get three or four armboards easily out of the knock-out for a sink... I'll keep an eye on sufficient- size bits in the waste samples bin from our interiors team (unlikely- but sometimes happens...)
Tony L
Administrator
Not in my opinion/experience. To my mind the things an armboard has to do are largely contradictory, e.g. it must hold the arm firmly in place, but shouldn’t reflect energy back into the arm or act as a sound-board. It rapidly becomes one of those ‘what energy is where and where is it going/where does it end up’ questions. A complex one that likely can’t be answered outside a proper lab, and even then there are so many variables no broad theory would be applicable.
It is no secret after much experimentation with many decks and arms over the years I’ve ended up pretty firmly in the Nottingham Analogue camp when it comes to material interfaces, e.g. nothing beyond a gentle finger-tight for bolts holding the arm to the board, the board to the deck etc. Break as many bells as possible, stop ringing/resonance etc, but only resort to mass when there really is absolutely no other alternative. The more I listen the more I am convinced the 1980s view of “rigid” sounds like crap, and I’m sure it does so due to resonance and making arms behave too much like a tuning fork on a guitar sound-board (same with spiked metal speaker stands). I’m also convinced that high-mass, as in most modern huge high-end decks is just as wrong, they all sound dead and boring in much the same way to my ears.
Bottom line is to experiment. What matters is how your particular arm is interfaced to your particular deck. It certainly makes a big difference and you should form preferences between materials and torques pretty fast.
That is where my mind was going with this. I guess the only realistic option is to try some and see what happens.
I've never gone OTT with tightening anything on a deck, purely because I'm a natural born ham-fisted bolt and screw stripper/snapper so I've always been super cautious, anything with a nut is usually hand tight or the slightest of nip with tools.
There's quite a long list of tweaks I want to try on my lashed up deck, I'm just acquiring a few bits and thought I'd try armboards as well.
Tony L
Administrator
I made my YouTube debut about a year ago trying to explain the torque thing for another thread, and if anything the video makes it look tighter than I’m actually doing. Literally just until it stops. This applies to fitting the arm to the board too. I’m not saying I’m right, or that it is universally applicable, but it certainly works here, as it does on Nottingham Analogue, old Rega Planar 3s etc etc. Get it right and the mid-band opens right up, voices sound real in acoustic space, things grow in scale etc. I really advise folk to at least try this as even if in their context they hate it they’ll maybe leave understanding mechanical interface behaviour better.
sq225917
Bit of this, bit of that
What arm and plinth are you using, we can generalise.
Ynwoan is a good source, he's done identically shaped boards in nomex carbon ply, (sandwich and triple laminate), alloy, alloy CLD, HDF, hi-macs and a few others. The carbon, nomex carbon, nomex, carbon with no cld is his daily driver. Slightly favours mid and top frequency clarity, no bass over hang. On a well damped suspended carbon nomex chassis with an Aro on high mass tubular stand.
Ynwoan is a good source, he's done identically shaped boards in nomex carbon ply, (sandwich and triple laminate), alloy, alloy CLD, HDF, hi-macs and a few others. The carbon, nomex carbon, nomex, carbon with no cld is his daily driver. Slightly favours mid and top frequency clarity, no bass over hang. On a well damped suspended carbon nomex chassis with an Aro on high mass tubular stand.
cobbers
pfm Member
Do not overdo it - bought a Systemdek once with multiple layers of damping everywhere and it just killed the dynamics.
I've use straightforward ply to good effect on a TD150. If nothing else it's a good place to start.
Corian and its derivatives are great for arm boards if you or someone you know can machine them.
Genrally i use Plywood or even laminate of thin ply and thin MDF, which is interesting.
Haven‘t got around to trying Bamboo yet, but hear it is useful!
Some of the best plywood I have come across is in old speaker cabinets from the 1960’s. Had a pair of Jordan Watts cabinets not so long ago, the ply was top notch!
Genrally i use Plywood or even laminate of thin ply and thin MDF, which is interesting.
Haven‘t got around to trying Bamboo yet, but hear it is useful!
Some of the best plywood I have come across is in old speaker cabinets from the 1960’s. Had a pair of Jordan Watts cabinets not so long ago, the ply was top notch!
Tony L
Administrator
It is very likely a good place to end too! From what I can work out ply or even chipboard is favoured on the TD-124. They appear more popular than acrylic, aluminium, slate, etc. I do have an original SME acrylic board for my 124, but preferred the Schopper and Stereo Lab ones (both ply I think, the latter certainly is). I also tried a Swissonor panzerholz armboard, and didn’t like it at all, though that was rubber decoupled by design so not a like-for-like comparison. Whilst I’ e certainly not tried everything I’ve come to the conclusion wood of some form, and very lightly attached, is my preference. Certainly good enough. If I had the woodworking skills/could be bothered to experiment I’d be interested to try a very light wood like balsa. I suspect the board is thick enough not to flex or resonate, and losing mass could be interesting.
FWIW with a DIY TD-150 I’d be inclined to remove as much of the armboard (and subchassis) as possible. The TD-160/RD80 make more sense to me than the TD-150 or Linn approach of having a huge plank of an armboard attached to the chassis only in the middle. The 124 gets away with it as the board is supported/attached to the chassis at the periphery.
Nothing wrong with the thinking there. Balsa though, that would be tricky. It warps like hell and being mostly fresh air if it's left as a straight board rather than a structure it has all the structural integrity of a crisp packet. Laminate it up, it might work then. It works well in model aircraft, but those are all built up designs that engineer in stiffness by means of the construction.
The Captain
~~~~~~~~~~
My feeling is this is similar to speaker cable. You can experiment & convince yourself you hear X difference now having put a different material board in. But you'd just be saying what you want to conclude.. when there's no actual difference, or nothing detectable with the ear. In a lab only.. yes differences could likely be detected, is my view.
Remember our biggest foible is we're extremely & ridiculously easily persuaded. And then we follow like sheep.
Caot
Remember our biggest foible is we're extremely & ridiculously easily persuaded. And then we follow like sheep.
Caot