Tonearm vibrations, Headshells and Cartridge coupling

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YoungDave

Re: Tonearm vibrations, Headshells and Cartridge coupling
« Reply #40 on: 16 Apr 2011, 03:23 pm »
Anyone tried the Cartridge Man isolation device? http://www.thecartridgeman.com/isolator.htm

It got some favorable press a couple years ago, but I have not heard much about it lately.  Seems like a good idea, but rather pricey.

I have a JMW 12.6 arm & Dynavector XV-1s, and the arm definitely couples vibration energy to the cart.  There is probably conduction in the other direction as well, that is, from the cart up the arm.  If I click my fingernail on the plinth or arm while the arm is not on the record, I can readily hear the click in my speakers.  Peter Lederman at Soundsmith is now using a Moerch arm on his HR-X, and he suggests wrapping JMW arms in a rubberized tape such as plumber's tape.  One could also try Herbies at certain points along the arm.  Both of these tweaks would add mass to what is already a fairly hefty effective mass.

Maybe the small constrained-layer isolator at the cart/headshell surface is a good idea - anyone tried it?

Cheers

dlaloum

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Re: Tonearm vibrations, Headshells and Cartridge coupling
« Reply #41 on: 16 Apr 2011, 04:01 pm »
An Aussie has put out a similar device...
http://cgi.ebay.com.au/cartridge-isolation-device-Australian-made-tonearm-/250757250682?pt=Vintage_Electronics_R2&hash=item3a624bfe7a#ht_2546wt_1139

Not as sophisticated, as the screws go through it and provide a path for vibration - but it will damp and absorb some... (just not as much as a properly isolated solution like the cartridge man)

Depending on the problem frequencies, wooden shimms can be used as well - eg: http://cgi.ebay.com.au/Headcell-Damper-HD1-5-HD2-0-Cartridge-Mpingo-clubWOOD-/190428266082?pt=LH_DefaultDomain_0&hash=item2c5668be62#ht_2016wt_1139

Then there are damping layers built into some headshells (AT-LS10, Denon PCL-6 both of these have a rubber damping layer).

Then you can try the plasticine / modeling clay dot, on the headshell under the leads (behind the cartridge) - 1/4" to 1/3" dot was recommended by Van Alstine (a well known audio engineer).

One of the very best options is the fluid damping trough tweak - sticky tape a straightened paper clip to the rear of the arm, attach a vertical and a horizontal paddle to the tip of it, and have that tip sitting in a trough filled with high viscosity fluid (oil / silicone ) - the trough is there to allow the arm to move through its range while keeping the paddles in the liquid.

This has double advantages - works to absorb/damp/dissipate HF vibrations, but also controls low frequency arm/cartridge resonances. (level of damping can be varied by varying the size of the paddles and/or the thickness/viscosity of the liquid).

lots of possible solutions...

Another option is to go for a higher compliance cartridge.... the energy conversion is more efficient and less is pushed back into the arm by the needle. (ie less energy is transfered into the cantilever suspension, which passes it to the cartridge body - then to the arm - then the reflected vibrations come back down to muddy the sound in the cantilever....)

High compliance systems inherently suffer less from these types of issues.

Of course the downside is that high compliance prefers low mass arm - and additional damping solutions on the arm add mass.... so the high compliance solution often involves an arm with less damping material on it. Compromise compromise compromise....

bye for now

David

BaMorin

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Re: Tonearm vibrations, Headshells and Cartridge coupling
« Reply #42 on: 16 Apr 2011, 04:17 pm »
The Sony PS-X5, PS-X6 and PS-X7 all have the same footers, and they are very effective. Once in awhile, a set will be on eBay, if your looking.

Wayner

Yep, I have an extra set...........and I'm always looking for more.  IMO probably the best feet ever put on a table.

neobop

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Re: Tonearm vibrations, Headshells and Cartridge coupling
« Reply #43 on: 16 Apr 2011, 04:32 pm »
High compliance systems inherently suffer less from these types of issues.

Of course the downside is that high compliance prefers low mass arm - and additional damping solutions on the arm add mass.... so the high compliance solution often involves an arm with less damping material on it. Compromise compromise compromise....


Yea, funny how that works out. High compliance carts are mated to lightweight arms that are often more flexible and sometimes have open bearing housings on the ones for vertical movement. Expensive heavier arms have better bearings, or heavier duty bearings and more rigid tubes that work better with lower cu. The trend seems to be toward med mass arms and you sometimes get what you pay for.

There was a review in one of the Brit mags on the Cartridge Man Isolator. I think they tested on a Rega arm with a Music Maker or Grado. Results weren't pretty. Some people say they get good results, so I guess like all of these tweaks, YMMV.

The same holds true for coupling vs damping. You just have to try and see what happens. Sometimes a combination of both works best.
neo

dlaloum

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Re: Tonearm vibrations, Headshells and Cartridge coupling
« Reply #44 on: 16 Apr 2011, 04:37 pm »
The ultimate (in direct coupling) being of course the traditional steel needle direct connected to a big horn....

Now that's what I call low compliance....

rollo

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Re: Tonearm vibrations, Headshells and Cartridge coupling
« Reply #45 on: 16 Apr 2011, 05:15 pm »
Maybe I shouldn't rag about Mapleshade. When you consider the R&D and all the hard work that went into the development of these couplers  :roll:  I get a little peeved with some of the seemingly outrageous prices charged to audiophiles. On the other hand with charge card expenses and returns, they have to have some incentive to offer it. I'm surprised Herbies doesn't have them. We have 2 testimonials about the possible benefits and it might be worth checking out. This thread has only been going a few days.

I'm sure not everyone is interested in all these articles. But for those into DIY tables or arms, there's design considerations here that can point you in the right direction. I haven't seen expert info like this offered elsewhere. I've seen some cool looking DIY tables. Most look like they'd be inferior sonically to commercial offerings even if they look beautiful. In the Stereophile interview he talked about the use of a counter pulley located on the opposite side of the motor pulley with a belt drive. This is unique and worth considering IMO. The only thing remotely like this is the VPI Classic locating the pulley at 7:00, opposite the arm pivots, like a Pink Triangle. My plan for using a Teres outer rim drive will locate the wheel like this. This addresses vibrations effecting the plane of the cart as it tracks the arc, but falls short of applying equal pressure on either side of the platter. I don't think you could do both and locate a counter pulley near the arm. There's no possibility of a counter pulley with a rim drive anyway, but it's something to consider with a belt drive.

Some of the subject touched on, are tonearm/headshell vibrations, counterweight coupling, cart vibration dissipation, arm mass/inertia - vertical vs horizontal, platter/bearing design, platter construction, suspension considerations and the use of a counter pulley. Any comments or ideas are welcome. Here's another link:
http://www.tnt-audio.com/sorgenti/belladonna1_e.html

neo


 Correctamundo. The change is well worth the $95. I'll agree that the descritions by Mapleshade are out there at times, however every product so far we purchased has delivered what was promised. ron and Pierre measure things to death. Nothing leaves their stable untested or unproved by their measurements.
   Besides they have a moneyback guarantee. Pricing one thing results another. I have had the experience of hearing an all Mapleshade system. TT thru speaker[ modded Gallos] all I can say is wow. cost prohibitive for most but again a major achievement in playback.
  If you call Ron he would be more than happy to advise you with your endeavor.


charles

neobop

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Re: Tonearm vibrations, Headshells and Cartridge coupling
« Reply #46 on: 18 Apr 2011, 05:58 pm »
To damp or to couple, that is the question.

I have a feeling that 1 piece arms, w/o removable headshell or wands, would tend to benefit more from coupling and others might benefit from damping. Of course there are too many variables, like carts and feet etc, to make any rules. I'd think it would be easy enough to try both.

That damping sheet that Proton46 linked to looks great. You get a 2' x 2' sheet for around $20. It is self-adhesive and you could use it for all kinds of other stuff like electronics. It doesn't have a middle squishy layer. I think that is a plus. Thickness is around 1.4mm.
http://www.smallparts.com/vibration-damping-sheet-040-thickness/dp/B0015RVDOO/ref=sr_1_4?sr=1-4&qid=1302823618

I've been thinking about the DIY coupling thing. An old fashioned thumb tack, the kind with the flat head, should be perfect. You'll need a pr of wire cutters to shorten it a bit. I don't think there's a need to sharpen it. If you want to try 3, you might have to trim the flat part. Use your needle nose to hold it while trimming and get the length as even as possible or you'll screw up the azimuth. Now that I think of it, this would be a great way to adjust azimuth on arms with no adjustment. A package of thumb tacks must have 20 to 40 pieces. So you'll have plenty to make a matched set.
neo

dlaloum

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Re: Tonearm vibrations, Headshells and Cartridge coupling
« Reply #47 on: 18 Apr 2011, 09:23 pm »
Coupling damply sounds interesting.... :icon_twisted:

The vibration damping sheet looks good - now I need to see whether I can find a local supplier.....

Photon46

Re: Tonearm vibrations, Headshells and Cartridge coupling
« Reply #48 on: 18 Apr 2011, 11:45 pm »
Another DIY experiment with damping cartridge vibrations that yielded positive results worth mentioning. I laid up carbon fiber matting with slow cure epoxy resin to make a sheet 3mm thick give or take a little. You start with as flat as surface as you can find, I used a machined steel table top. A sheet of polyethylene plastic sheet gets stretched and taped down over the flat surface. The carbon fiber and epoxy gets laid down over the polyethylene. Use slow cure resin so air bubbles can dissipate. Stretch another sheet of plastic over an appropriately sized sheet of smooth Formica, granite, composite stone, etc. Use spacers of some sort on the corners of the overlayment board to control the thickness of the carbon fiber sheet. Lay the overlayment sheet on the wet epoxy and carbon fiber mat, wait 24 hours, and you'll have a beautiful bargain priced vibration damping sheet to use for DIY projects. I cut the material to use between headshells and cartridges. For my cartridges, I ended up preferring the SmallParts sheeting. Someone else with different kit might prefer the carbon fiber. You can buy carbon fiber and the resin online in various places as well as shops that supply the boat building trade. Just beware, carbon fiber is TOUGH as hell to cut, sand, and drill.

BaMorin

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Re: Tonearm vibrations, Headshells and Cartridge coupling
« Reply #49 on: 19 Apr 2011, 02:51 pm »
Another DIY experiment with damping cartridge vibrations that yielded positive results worth mentioning. I laid up carbon fiber matting with slow cure epoxy resin to make a sheet 3mm thick give or take a little. You start with as flat as surface as you can find, I used a machined steel table top. A sheet of polyethylene plastic sheet gets stretched and taped down over the flat surface. The carbon fiber and epoxy gets laid down over the polyethylene. Use slow cure resin so air bubbles can dissipate. Stretch another sheet of plastic over an appropriately sized sheet of smooth Formica, granite, composite stone, etc. Use spacers of some sort on the corners of the overlayment board to control the thickness of the carbon fiber sheet. Lay the overlayment sheet on the wet epoxy and carbon fiber mat, wait 24 hours, and you'll have a beautiful bargain priced vibration damping sheet to use for DIY projects. I cut the material to use between headshells and cartridges. For my cartridges, I ended up preferring the SmallParts sheeting. Someone else with different kit might prefer the carbon fiber. You can buy carbon fiber and the resin online in various places as well as shops that supply the boat building trade. Just beware, carbon fiber is TOUGH as hell to cut, sand, and drill.

Not to mention, the dust produced is as dangerous as asbestos, or beryllium. Wear a very good breathing/filtration device. Do not launder the clothes worn with other clothing, wash at least 3 times.