AudioCircle
Industry Circles => Audio by Van Alstine => Topic started by: Wayner on 24 Jun 2010, 09:08 pm
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I recently scored a nice AR ES-1 tonearm and the floodgates have opened for a new table project.
(http://www.audiocircle.com/image.php?id=32005)
The platter and bearing will be from the AR-XA turntable, motor is the Hurst 3001-001, 300 RPM synchronous (12 pole) and the the body may be 5/4 composite deck plate. The motor assembly will be like the one in ARMod, separate from the table body and linked only by the belt.
The decking material is made from recycled material and I believe it to be sonically inert as well as expansion/contraction stable, so a good candidate to couple the platter and tonearm together. I also know that the decking material is extruded and has hollow sections within it, perfect for stuffing lots of platiclay into. My friend is going to precision water-jet the mountings for the platter and arm base and will hold tight tolerances.
That's the new plan, anyway.
Wayner :D
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COOL looking arm! So why can't I find any info on it? Seems the ES-1 is a turntable that never has this arm on it. :scratch:
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keep us posted !!
:green:
Mark
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Motor starting capacitor finally arrived. This motor is made by Hurst (a division of Emerson) and is a very torque loaded. It is also an excited motor, that would not work suspended, because of it's internal energy (mechanical) and must be designed in a housing that will drain off the mechanical energy. Running the motor as shown, one can feel the pole locking vibrations, but with pressure to the two mounting tabs, can render the vibration to almost zero.
(http://www.audiocircle.com/image.php?id=32198)
This means the table design will have to have a SAMM (stand alone motor module), to keep the motor completely isolated from the plinth. I am also going to have to consider a mounting method that will put the motor under pressure, against some mass, to drain the mechanical energy. The centers of the mounting holes will also have to be inline with the table spindle, to prevent the motor from hinging on the 2@180 degree mounting holes. This is kind of a bad design, and I wish the motor had 4 mounting holes in a bolt square. If I want to use this motor, I will have to over come this problem.
Wayner
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Could one 'suspend' the motor in a cavitiy in the plinth using compliant cords (aka mini 'bungee' cords) to decouple the motor and sink the mechanical energy a la the Pro-ject Debut??
Could one house the motor in the plinth inside a 'can' filled with plasticlay? The outer appearance could then look like the VPI classic, but the hole in the plinth could be enlarged so as to not touch the 'can' housing the motor? Lots of options to optimize the aesthetics.......
Looks like a great project, Wayner.
Mark
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Mark,
Almost all of this design is driven by the tools that I own. That would be a nice drill press and a power miter saw. Cut and drill, that's about it. There is that old saying from design skool, that "things look like how you made them". Again, from my many years in manufacturing, I have learned that it is not what you make, but how you make it. When I get to drilling the holes for the tone arm and platter bushing, I'm going to see my buddy who will put those holes in at a tolerance of +/-.0005. The rest will be done by myself as they are no where near critical at all.
My design (in my head) can go 2 possible directions. In the first design, it will look and function like ARMod, using different plinth and SAMM materials. It will be easier to make, but I may need my buddy to make me some end caps to cover the 5/4 decking material (to make it perdy).
The other design came about after a couple of beers the other night. I'm using an AR-XA platter, sub platter and bushing for the turntable. If I eliminate the outer ring and put a 1/4" thick piece of poly on top of the sub-platter, I can put the motor and pulley assembly much farther away, using a longer drive belt. I can't cut any material until the arm arrives, so I'm slightly on hold.
Wayner
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Wayne - do you have any kitchen contractors around your area? Do any of them make Corian countertops? You may be able to pick up a sink cutout and make a Corian plinth out of it; a very inert and dead material.
Be careful cutting and drilling it though. It kicks up a lot of dust.
Bob
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Wayner,
Ahhhh...I like the 'coupla beers' design idea...for as the apostle St. Paul said (of wine),
"No great poetry was ever written by a drinker of water."
Please post pictures, details,etc of the build. I know I will learn a lot about the innards and workings of TTs this way. :thumb: Thanks.
Mark
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The AR arm came yesterday. It's a really nice arm. The body pieces are carbon fiber, counterweight seems to be brass, with possible carbon fiber arm tube, and headshell. Everything is adjustable, including VTA and Azimuth.
(http://www.audiocircle.com/image.php?id=32369)
(http://www.audiocircle.com/image.php?id=32370)
Wayner
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Man Wayne you can sure find stuff that gets us going! :eyebrows: What vintage is this beauty?
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I think the arm is from the early 80s, but not sure. Not lots of info on it, but I haven't yet checked the vinylengine. Today, the mission is to get the new Sony PS-X7 going.
Tomorrow, I will officially start this project. I will be looking for input on a few ideas, so some if want, can put on the thinking caps.
Wayner :D
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Now I'm doing some fun math for calculating the best possible distance for spindle to pivot distance for the AR ES-1 tonearm. If I recall, the AR turntable and the ES-1 were kind of the same deck from the 80s. I know that most of these decks were fitted with a version of the AudioQuest PT series, like a 5 or 6. That P to S distance is 211mm as published by AQ. Using my Lofgren B calculator, that puts the overhang at 18.601mm, producing a 229.601 effective length from pivot to stylus. If I subtract the 10mm stylus to mounting hole spacing, that puts the mounting screws at about 219.6mm, or about 8.64 inches to at least the inside mounting screw (on the PT-6) and that also seems to put the mounting screw position on the AR arm at least in the slot area, so this should work.
W
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I think we have a good start on the design for the plinth.
(http://www.audiocircle.com/image.php?id=32431)
The material (composite decking) is very stable, and non-resonant. Tomorrow, I will start making parts, if I feel good about the design, tomorrow. The body is a double layer, encapsulating the bearing and tonearm collar. Haven't quite figured out how to exit out the RCA female jacks yet, but the logical place is out the back, or left side.
Wayner
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I am close to getting the plinth done. I'm going to quite for the day while things are going good.
(http://www.audiocircle.com/image.php?id=32465)
Wayner
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That P to S distance is 211mm as published by AQ
shouldn't this is where the hole should be from the center of the spindle?
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Yes, centerline of spindle to centerline of tonearm pivot.
I have the main structure finally assembled today. Had to redrill an inner hole, no big deal. I also had to shorten the length of the body, behind the tonearm, as the leads from the tone arm were not long enough, and I didn't want to splice them. My only goal tomorrow is to get the RCA jack plate installed, and wired. Then this portion will be done and on to the SAMM.
(http://www.audiocircle.com/image.php?id=32492)
(http://www.audiocircle.com/image.php?id=32491)
Wayner
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Then the hole for the arm should be 211mm from the spindle, not 219.6mm.
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P to S stands for Pivot to Spindle, not pivot to stylus. 211 from pivot to spindle it is.
Wayner
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That's want I meant, that's where the hole for the tonearm should be drilled. Then the 219.6mm has no bearing for the installation, it just confuses the issue, because once the hole is drilled, there's nothing you can do about the pivot to stylus, you just have to live with what you have, pivot to spindle is the key to tonearm installation.
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OK, I didn't mean to confuse anyone. Oh, I get what may be confusing. The 219.6mm is the distance from the tonearm pivot to the screw holes on my cartridge. I had to know this number to make sure the cartridge had enough "slop" in the slots to achive the points I wanted. 219.6 has no other reference to anything, and is just a number I used to do a check on null point geometry.
Wayner
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The table is done. I haven't installed a cartridge yet, perhaps this afternoon. The little wires are fun to solder. I put the grounding on the left shield as many of the turntables, like AR and Rega do. It's just easier to do.
I also polished up the outer rim to "pretty up the pig".
(http://www.audiocircle.com/image.php?id=32522)
(http://www.audiocircle.com/image.php?id=32523)
Wayner
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That was quick! If you'd put nice cover plates over the holes, it'd make a really great looking turntable design too.
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I thought about that, but I'm a form follows function guy, and cosmetics usually suffer. :D
I actually like the industrial look. It looks different in person, as you get the effect of 3D in the shape of the decking material.
I have to make a comment on the decking material. All I can say is wow! This stuff is awesome. It's dense, yet goes thud then you hit it, it's got a waxy feel to the surface, easy to machine and is dimensionally stable. It was just wonderful stuff to work with. I think it's made out of recycled paper, cause when you drill it, it comes out like paper, but is some tuff stuff otherwise.
My wife commented on the natural finish of the material, and she likes the color and texture. This was a fun (and fast) project, but I'd been thinking about this one for a long time, just waiting for the right tonearm to come along.
Wayner
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Is this decking material as dead as MDF? I saw what you were using, and was concerned that it's hollow-nature would serve as a resonating chamber... It seems that it's hollow-nature would reduce the intensity needed to create constructive interference of (sound) waves.
I've been building speakers for a while, and have just resigned myself to 1.5 inches of MDF lined w/ dynomat (or--the generic version, actually). Everything else that I've tried--even with my best attempts at bracing--just seem to fall short.
If there's a better mousetrap out there, I'd love to know...
I love your work, by the way. Very, very imaginative and out of the box!
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Is this decking material as dead as MDF? I saw what you were using, and was concerned that it's hollow-nature would serve as a resonating chamber... It seems that it's hollow-nature would reduce the intensity needed to create constructive interference of (sound) waves.
I also know that the decking material is extruded and has hollow sections within it, perfect for stuffing lots of platiclay into.
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I plan on stuffing the hollow with "something". Be it plasticlay, sand or what ever, that was the initial plan. I'm not going to go into the speaker building theories, but for me, the stable mass and dead sound of the material was, for me, the way to go. I've learned from making ARMod, that all vibrations need to be squelched. I'm not sure if MDF is that material.
I'm doing this project cold turkey, so if I fail, it's out in public, but I think I'm on the right path. ONLY playing the table will reveal the true nature of my engineering. There are going to be tweaks. If any of you know about ARMod II, it was burnt up in a midnight recreational fire. Can one have success without failure? If your in any kind of engineering, you have worn lots of egg on the face. It's humiliating. It's really fun to see young people entering the field and making the same mistakes I did, when I was 22. That is part of growing up. It's two worlds apart. There is the design, and then the reality. I believe that Edison tried over 10,000 different materials before he found that tungsten in a vacuum would glow. The guy never gave up. Hense the old saying that genius is 1% inspiration, 99% perspiration. I'm of the later skool.
I have 3 US government patents, made $3 dollars off of those, and believe me, the effort was not rewarded, having the patents is.
I fear the motor module that is next. Lots of machining.
Wayner.
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I'm doing this project cold turkey, so if I fail, it's out in public, but I think I'm on the right path.
At first, I thought it read... but I think I'm on the right plinth. :roll:
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Richlite counter top material is another dense material that is non-resonant. Richlite is also made from paper and can be machined with woodworking tools. I glue it to the inside of speaker cabinets with great results, it might be great as turntable base and platter material too. I got free scraps from a local dealer but if I remember correctly it's about $25 sq. ft.
I have photos here:
http://www.audiocircle.com/index.php?topic=72808.0 (http://www.audiocircle.com/index.php?topic=72808.0)
Wayne
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Lookin' good! What does the plinth weigh in the nude? A mix of sand and lead shot between Plast-i-Clay "caps" would be my suggestion for filling. I am partial to wiring my tonearms with Cardas Tonearm Wire from clips to ETI Copper Bullets. I like less connections for the same reason you would not splice the cables. But that's just me. :roll:
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Looks good, Wayner.
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Looks great---snug up a Longhorn on that baby and let 'er rip.....
Mark
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Deck material may be environmentally stable being used outdoor, but I am not sure if it's mechanically stable, it's light.
traditional MDF, acrylic, tufnol, or wood (like the CJ Walker) would be a better choice. You may want to fill it with concrete to make it more solid and rigid, but it'd be too labor intensive.
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(http://www.audiocircle.com/image.php?id=32576)
It lives! I decided that I couldn't wait to hear the deck, so I'm using ARMod's motor. I had to shim it up about a 1/4" so I used a computer mouse pad. Initial thoughts are as follows, rcag_ils's concerns about the decking material being mechanically "unstable" or light, seems to hold no weight at all. The table is very quiet, free of mechanical noise, or the result brought up by the cartridge and tone arm.
The tone arm during initial install had some issues. First, with the AT-440MLa cartridge installed, I could not achieve zero balance. I was always a bit suspicious of the counter weight, as it looked small to me, but the counter weight post was also longer then normal, so I thought no big deal. Well, the fix was a 1/2" brass washer, affixed to the back end of the counterweight with some good old plasticlay.
The anti-skating was the next issue. I track the AT at 1.6 grams, and setting that number on the anti-skate dial, had no effect. Using my blank disc, I was able to dial it in a 3, to get a tonearm to stand still between the null points. It will track correctly now. Also the screw holes ended up in the back third of the slots when aligned to Lofgren B, so I should be able to get any nulls I want. That worked out well.
Third I have a very minor hum at about a 1 O'clock volume position. This is beyond the normal listening levels, so I may ignore it, but remember I used the left audio shield to ground the arm. I may remove them from the shield and put on a separate ground. I remember Frank warning that with some arms, this may be a problem.
(http://www.audiocircle.com/image.php?id=32575)
I think at this point, there will be no plasticlay added to the hollows.
Wayner
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Looks real sweet Wayner. Keep us posted on any tweaks. And now that's on item on the list you can cross off ! :thumb:
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Wayner,
Very nice, indeed ! In the light, in these photos, I really see what you mean about the "industrial" look of the project...I like it a lot !
Dial it in with a Longhorn and let us know what that's like.
Cheers,
Mark
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The Stand Alone Motor Module (SAMM) is done and so is the fabricating part of the project. Below are some photos of the guts of the SAMM, and a finished shot of the complete table assembly.
(http://www.audiocircle.com/image.php?id=32710)
(http://www.audiocircle.com/image.php?id=32711)
(http://www.audiocircle.com/image.php?id=32712)
(http://www.audiocircle.com/image.php?id=32713)
Now we do the de-bugging, gettting rid of as much noise as possible. I have not heard it with the new motor.
Wayner
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I have found one little noise maker on the arm. It's the plastic weight dial on the counterweight. It's too loose, and for now, I have plasticlayed the bugger, but I may epoxy it permanently.
After some consideration, and figuring out how to accomplish the task, I have installed 4.4 pounds of plasticaly into the innards of the plinth. I have about 1 pound in the SAMM, but I'm almost out of clay.
Tip of the hat to Frank Van Alstine and John, TheChairGuy for being big promoters of plasticlay in turntables. It is the number one anti-vibration drug out there for calming down all those little nasties.
I simply don't know why table manufacturers don't put hollows in their tables plinths and stuff them. They will reap many rewards.
Wayner
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Wayne I wish I had the guts to try something like this very very nice !!
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Nice work Wayne :thumb:, I bet it will sound wonderful. Really a nice project, loved the decking material used also.
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You should go onto business, brother!
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Thank you all for your kind comments. Once in a while, a project works out. Today, I decided to take some of your advice and "pretty up the pig". So I added some birch covers to the ends of the plinth and SAMM.
(http://www.audiocircle.com/image.php?id=32800)
I'm running out of tweaks, but would appreciate an idea of how to slow the queing descent. Perhaps some lithium grease?
Wayner
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So Wayner, ......hows about some sonic impressions??
What did you learn in the execution of the design concept? Anyhing that you would do differently, or plan to modify ?
C'mon...share !
Still looks cool, by the way.
Mark
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OK. It is the quietest TT in the fleet. It's scary quiet. It beats the Sony, VPI, Technics and Empire. The arm is also very impressive (with one small problem) and reveals source material on a level I never heard even at RMAF. Very 3D and spacious sounding.
Andreas Vollenweider, Freidmann and even Supertramp are riveting. I'm sorry, I'm not BS-ing anyone here. I really don't know what to think. The composite decking material was the right choice, along with about 5 pounds of plasticlay.
I am going to bring this over to Frank's when I get some time. Mark, if you want to show up then, you'd be also welcome. I'm going to play some of my new music from this weekend and try and figure out where I went right.
Wayner :D
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I'm sorry, I'm not BS-ing anyone here.
Wayner :D
Every design has to start somewhere you may have hit right off the bat
sometimes it's better to be lucky than good as the saying goes...................Bill
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You gotta go onto business on that, bro. Wish I could hear it!
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Nice. Thanks for the invite. If it happens on a weekend, please let me know.
How do you think a combination of the decking material and clay would perfrom as an independent turntable platform??
Maybe this conversation can transfer to the Vinyl circle, but the idea is kinda intriguing, esp. given the low cost, versus commercial products (Ginko clouds, maple/myrtlewood, and granite/ marble, etc etc)?
M