tone arm board experiment

G

Gumba

New Member
Anyone try making a tonearm board out of different materals? I read somewhere that someone makes one out of carbon fiber. I decided to make one out of maple out of curiosity. I noticed a subtle difference. The background instruments were more noticeable (louder) and overall the sound was livelier. I made the board the same size and thickness as the linn board. The linn board, circa '87 weighed 9 oz. and the maple one weighed 7.2.

When I upgraded to the origin live dc motor a few years back I made a new plinth out of maple. I epoxied 1/4/20 studs into the corner blocks so I could use black diamond racing mk 3 pyramid cones. Since I did both at the same time I don't know what if any effect the maple plinth had.

Current set: Linn LP12 ('87), basic plus arm, Cardas cable, Benz gilder, Origin Live DC motor, maple plinth & tonearm board. Cetech sub chassis on it's way in. At some point I'll up grade the arm to an Ittok.
 
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I cut and arm-board for my Jelco 370H out of leftover 12mm Baltic Birch ply, which sounds pretty good. A couple of years ago, someone asked me for Rega arm hole locations for a diy arm-board using 10mm acrylic. Apparently, it turned out quite nice and supposedly sounded good.

My deck also has corner blocks and BD racing cones. I'm still using a Valhalla PS, but it's mounted externally in a separate box.

I'd love to see some pics of your deck, must look lovely with the maple plinth.

Jeff
 
Here you go. It sits on a maple Zoethecus stand. You can see how much the maple darkens down over the years.
I'm going to make a keel out of maple and see how it sounds. I'll compare it to the Cetech w/maple arm board.
 

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Well I was right, that plinth is quite lovely.:yes: You're obviously comfortable working with wood.

Not sure how a maple sub-chassis is going to sound though, could be disappointing, but you never know. The Cetech is supposed to sound very good, never had the pleasure myself. I was thinking of trying an aluminum/Baltic Birch ply sandwich for a sub-chassis with a custom bearing.

Jeff
 
Gumba said:
Here you go. It sits on a maple Zoethecus stand. You can see how much the maple darkens down over the years.
I'm going to make a keel out of maple and see how it sounds. I'll compare it to the Cetech w/maple arm board.
Click to expand...

very very nice.:drool: Let us know what you think of the Cetech
 
I installed the Cetech w/maple armboard with the through bolts. The bass was tighter, everything was brighter overall, and slightly faster. It was too bright for my tastes. My wife (unbiased opinion with better hearing at the high end of the spectrum) thought it was way too bright.

Next I made a insert for the stock steel sub-chassis out of 3/4" marine ply (see photo). It's a press fit. Got the idea from Vinylkid58. I mounted the maple arm board with through bolts. It sounded slightly muted and also a bigger sound stage compared to the stock steel chassis. So I would say a slight improvement, not as dramatic as the Cetech.

So if your looking to punch up the sound then you might try the Cetech. Like any other tweak, depends what your looking for.

My goal in making the the ply insert was to deaden the ringing from the steel. I had the wood and the tools to make it so it only took a few hours. Another, simpler option might be to try a 1/2" thick piece of foam rubber cut to fit inside the sub frame. Use contact cement to hold it in.

I'll be selling the Cetech w/Cirkus bearing, new Linn armboard, and will include one of my maple armboards if someone wants it.

Great fun!
 

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Thanks for the Cetech update. I think I'll try my own version.

You've inspired me to treat my steel sub-chassis with Silent Running SR1000 anti-vibration compound. Five coats on the underside and she's as dead as a doornail. A definite sonic improvement, a much lower noise floor as would be expected. Vocals and instruments are better defined in space, with more detail overall.

I also took this opportunity to flip the top plate over so the motor now sits in the 8:00 o'clock position. Not sure yet if this made any difference, need some more listening time.:scratch2:

Jeff
 
Good news. Someone else suggested applying a spray on undercoating. Getting rid of the sub chassis ring seems to be the way to go. Did you try through bolts for the arm board? Would be interesting to see if that does anything.
 
I haven't done the thru hole machine screws yet, I'm using hex head sheet metal screws which really clamp down the arm-board. The stock Linn screws are a joke. I remember laughing out loud the first time I took my deck apart.

Jeff
 
I applied spray on undercoating to my steel subchassis, and used bolts to attach the armboard. I tried an oak and then a poplar armboard, and I prefer the oak armboard. All in all I think the mods sound better, but beware if you want to apply undercoating to your subchassis because it would be a very difficult procedure to reverse if you find you don't like it.
 
vinylkid58 said:
I haven't done the thru hole machine screws yet, I'm using hex head sheet metal screws which really clamp down the arm-board. The stock Linn screws are a joke. I remember laughing out loud the first time I took my deck apart.

Jeff
Click to expand...

There is a reason for Linn using the 'joke' screws, Jeff ... they provide a lossy connection between the armboard and the pressed-steel subchassis.

In other words, rigidly attaching the armboard to the subchassis (with through-bolts or larger screws) is not a good idea unless you do what you seem to have done ... kill the vibrations inherent in the pressed-steel subchassis.

Cetech were able to bolt the armboard because the CF-composite subchassis does not have the vibration problems inherent in the pressed-steel subchassis. Hence this rigid coupling allows more low-level information to be extracted from the grooves.

Regards,

Andy
 
Gumba said:
I installed the Cetech w/maple armboard with the through bolts. The bass was tighter, everything was brighter overall, and slightly faster. It was too bright for my tastes. My wife (unbiased opinion with better hearing at the high end of the spectrum) thought it was way too bright.

Great fun!
Click to expand...

Interesting experience. I have a Cetech with a CF/balsa/CF composite armboard which I had made up. I don't find it too bright! :tresbon:

So IMO there are 2 possibilities with yours - assuming you bolted your maple armboard to the Cetech:
1. maple is not a good material for an armboard?
2. you wound the nuts up too tight on the bolts ... so the bolt-heads stressed the armboard? I found that the nuts had to be tightened "just so" (like Goldilock's porridge! :D ) - too tight and it stressed the armboard and the sound became (in my words) "harsh" ... too soft and the armboard wasn't rigidly attached.

Regards,

Andy
 
I have a Cetech "bolted thru" the original Linn armboard. It sounds terrific!
Cetech is now providing a carbon armboard but the inside middle layer looks like the stock original Linn board: it's not aluminium honeycomb like the subchassis! there is only two external carbon fiber layers... It's at my opinion, only a cosmetic improvement that let people watching the carbonic armboard! the price for this carbonic armboard at £99 is crazy!
 
Hi,
Talk of sub-chassis up-grades have look at Sole Sub-Chassis for Linn LP12
http://www.analogueinnovation.com/page4.htm
I don't have a Linn I have a Thorens TD150 modified with a custom made Sole Sub-Chassis Linn springs rubber & bolts Linn size armboard, Mose/Hercules II psu.It has been a labor of love and sounds great.
 

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rkay5 said:
I don't have a Linn I have a Thorens TD150 modified with a custom made Sole Sub-Chassis Linn springs rubber & bolts Linn size armboard, Mose/Hercules II psu.It has been a labor of love and sounds great.
Click to expand...

Very nice Robert. I'll assume the Sole is a significant upgrade over the stock sub-chassis. Sorry, I'm not familiar with the Thorens. Also having the PS outboard is another bonus. I did that with my Valhalla a while ago.

I'm going to diy a Sole for my table. Just have a couple of other projects to finish first.

Jeff
 
Jeff,
The Sole is one hell of a up-grade as the stock TD150 sub-chassis is a little T of thin steel and the Bearing press fitted into sub-chassis. Now with the Sole it's cold pressed about a 1" aluminium mounting backet see photos.TD150 Sole 0011.JPG

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Thanks for the pics Robert. Most interesting indeed.:yes:

Any idea how thick the Sole top plate is? I have 1/8" Al. sheet here that I can use.

Jeff
 
Its great to see people still posting to this thread. I'm really interested in hearing everyone's attempts at upgrading their LP12's with non Linn products. I've upgraded mine with the Origin Live advanced motor kit and the upgraded transformer, and I've found it to be a noticeable improvement. Its much quieter now, and there isn't a problem using my new Grado Sonata 1 cartridge (no hum with a DC motor).

By the way, can you use the original LP12 bearing and lower platter (pre cirkus) with the Sole subchassis?
 
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