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How to Make an Arm Board for a Turn Table


rplace

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I posted this in my upgrade or sit tight thread, but not getting any bites. I figured it might have been missed.

I think Allan has made armboards for his tables, wondering if others of you have and what is involved with it? Can it be as simple as knowing the distance from the spindle to the center of the hole for the arm and just drilling a hole? If it is more complicated what do I need to know?

I have seen lots of web sites that talk about making an armboard for testing a particular arm on a table, but none that I find tell you the process. Anybody have a link to sites that discuss table mods?

I’d like to keep my current table intact and make something to test a different arm. I am probably not interested in altering my existing table.

Below is the info for my current arm, a pro-ject 9 arm which is mounted on my Music Hall MMF-5. The second set of info is for the arm I want to put on the table, an Origin Live Silver arm.

Pro-ject9Arm.JPG

Here is the info I found on the Origin arm.

  • Effective length: 240 mm
  • Effective Mass 14 grams
  • Overhang: 17.24 mm
  • Offset angle: 23 degrees
  • Mounting distance (platter to armhole centers): 223 mm
  • Mounting hole diameter: 24 - 25 mm
  • Maximum armboard thickness: 27 mm
  • Length of external cable: 1.2 meters
  • Cable capacitance: 0.002 uF
  • Cable resistance: 0.002 ohms
  • Total weight: 448 grams
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Marty, My MMF-5 is set up for the Pro-ject 9 arm that shows 212 while the Origin/Rega is 223. Pretty close, but I would think they need to be exact. I also found some info n th Pro-ject saying it was a standard Linn mount if that means anything to anyone.

Still looking for help.

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Okay that's too much of a difference in distance. You can be off a mm or so but I doubt you'd want to be much more than that. I do believe a standard Linn arm is rectagular in shape and made out of either hardwords and/or composites. I'll see if I can track down an example for you.

What you would do is build the board so it will fit onto the table, install it andthen make exact measurements from the center of the spindle to the proper distance and then drill out a armhole (23mm for Rega) from that exact center of that measurement. On the P3's you need 250mm clearance from the armboard hole to the inside front edge of lid. I've got a online printout of how this all looks which I will also try to track down a link for you. If not I can mail you this one.

I'll go surfing and get back to you.

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Just read your other post. If you are trying to mount this on a Music Hall TT with an arm board I'm not sure that would work at all. First it would raise the arm too high. Second you would still have to drill into the plinth of the Music Hall and that would kill it's resale value. If you did drill into the table you could use a large washer underneath the arm to keep everything in place.

Or, you could simply drop the arm into my own Rega P3 and see if you like the difference. I have my RB300 off the Rega because I'm using it on my Ariston RD11s. Be happy to lend the Rega to you.

Oh and if you want to try out your woodworking skills and can make a perfect circle I could use a hardwood armboard for my Ariston. Dimension are 3/8" thick and 3 and 3/8" wide. I will then drill out the holes to fit.

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Marty, all great info thanks. I was thinking of something like that ebay listing, but was also concerned with the extra height it would add. I was not sure in my mind how to get around this. I was also thinking I would still have to modify my table's plinth to match up with the armboard.

My table has a split plinth where the bottom part holds the motor and the top part is isolated with 6 rubber "springs". In a nutshell it is a rectangle with the spindle mounted on it and a hole for the arm with 6 small indents on the underside for the 6 springs. I don't thin it would be all that hard to have that top part duplicated, but I think it is beyond my skills. I wonder where I could get something like that done?

Still I see lots of online info about people swapping out arms or modding a table to take different arms and not sure how they pull it off. Perhaps is more difficult then it appears or maybe it is just that some tables lend themselves to this better then my set up. If I could get a top part to a MMF-5 and cut/alter it I think that might be the best route. I would just enlarge the current hole, then sandwich two large washers above and below. Then I could position the two washers to my needs for the new arm and keep the original arm on the current top. But where to get that top part at a reasonable price?

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Rich,

To me, the Music Hall MMF 5 is not really a good table to be swapping arms on. Since the arm mounts right on the main plinth, there is no way to mount a different arm without drilling holes all over the plinth. I would say for the most part, no two arms use the same mounting location. Every arm should come with a mounting template that is specific to that arm. Usually the template uses the spindle as a locating point and then you mark and drill your tonearm mounting holes where the template shows.

All these people swapping arms you read about are usually doing it on turntables that have an accomadation for a separate arm board. Think Thorens TD124 in the vintage realm or look at a Sota type for newer style. These are made to easily swap just the board where the tonearm mounts, allowing you enough room to vary where exactly where the tone arm is placed in relation to the platter spindle.

Not to say you can't mount any arm you want on any turntable.... just that if you want to be "swapping" them in and out, that's going to be tough to do on an MMF5.

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Thanks Scott,

I was sort of coming to that conclusion myself. I posted a want add on A-gon hoping to find somebody with bad MMF-5 that I could take the top plinth off of and hack up, keeping mine in original shape. No luck so far. I also wrote Music Hall, Needledoctor and a few others. Those that did reply said they could not get the top plinth for me. Bummer. Hard to believe Music Hall won't sell me one. Roy Hall himself wrote me back. I guessing he gets the whole tables form the Pro-ject factory and does not have access to parts...or does not want to bother with a one-off order.

I don't think it would be all that tough to make the top part, if I had access to more sophisticated wood working tools. I think getting the spindle mount might be the toughest part. On the bottom side there are 6 little indents for the "springs" if you are familiar with the table. The look to be done with a drill press all to the same depth.

Do you think a cabinet making shop would do work like that if I took in my original table stripped of all the other parts?

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The MMF-5 uses a cup to mount the arm and doesn't have an arm board per say and makes it very difficult to mount another arm. You have to get a blank cup (If available) from Roy at Music Hall, even then it would be more of a pain in the *** than its worth that is if it can be done in the first place. I recently built a Rek O Kut table (See avatar), an L-34, I built a 6 layer birch ply plinth and you can install any arm you want and can experiment with arm board materials. I did it all in 1 day and had a lot of fun doing it. Best of all it sounds a lot better than an MMF-5, I did my table all for $125.00. I have since sold that table and am starting another Rek O Kut project this time with a B-12GH. Good Luck.

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  • 1 month later...

Time to bring this back to life. I have been looking for a broken MMF-5 or just the top plinth to modify, while keeping my original, well, original. I'll post a few pix and offer up my plan on the thrid post. Open to any and all ideas.

Here is the table as seen from the top.

post-16462-1381937448785_thumb.jpg

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Please read the previous two posts on page 1

Here it is with the two pieces split up. My plan is to route out an area say 4"X6" around where the current arm is about the depth of what you currently see where the plater goes. Then make a 4X6 piece of wood that will serve as a blank "arm board" for lack of a better word. I will then put a hole the correct size and location for my new arm. If I ever wanted to put in a different arm I could just make a new blank. Sound like a plan?

Probaby more work then this cheap table warrents...but hey I already have the arm, so why not play around.

Anybody got a better idea? How about a scrap the whole plan and get a Technics 1200. Kidding, kidding and ducking[;)]

BTW, please excuse the mess.

post-16462-1381937448883_thumb.jpg

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I have recently found the sonic pleasure of old AR and Thorens turntables. They sound great they can be had for reasonable money. Some say they rival $2,000 and $3,000 set ups. Add a Rega RB250 to an old AR or Thorens. If you are not happy with the result they re-sell very well. The base tables can be had for $200-$500, the tonearm for $275. The arm boards are pretty easy to make or purchase. You could buy one all refurbished as well, check out www.vinylnirvana.com and www.theanalogdept.com. I am a wood worker of sorts and can make armboards if you have trouble finding what you want.

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I have recently found the sonic pleasure of old AR and Thorens turntables. They sound great they can be had for reasonable money. Some say they rival $2,000 and $3,000 set ups.... I am a wood worker of sorts and can make armboards if you have trouble finding what you want.

I totally dig where you are coming from and appreciate the suggestion, but I already know what the next table I get will be...that is if I decide to dump my MMF-5. I just cannot convince myself that my current set up is all I will ever need. Still I think about upgrades.

At any rate I have a perfectly working MMF-5 along with a Origin Live arm that has been sitting in a box for 2+ years. I now have a top plinth for a MMF-5 that I can butcher up and still keep my original unmolested. So good idea or not I think I want to try and make a way to have basically the same turntable with the only difference being the arm and see what the differences, if any, are.

It is your last sentence that has my interest. I am not much of a wood worker. However, I do have a router. I don't think it would be all that hard to make a routed out square hole that I could drop an appropriatly sized block into and in turn drill a hole in that block in the right place for my other arm. How does one make square corners with a router? Get as close as you can with a router bit then chisel out the exact corners? The MMF appears to be MDF, is that pretty easy to work with? Any other suggestions greatly appreciated. Thanks!

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  • 1 month later...

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