To damp or not to damp JMW-9 Sig ?


Just got this tonearm for my ScoutMaster. A great addition I might add. I haven't experimented with the damping yet. This will come. But I was wondering what differences I might hear with it damped? I'm using a DV 20XL cartridge. Thanks
128x128artemus_5
I asked that very question to Harry Weisfield of VPI and to Musical Surroundings. I have a Benz LP. Musical Surroundings said I can try but they recommnd very little if any. Harry said basically the same thing for my cratridge, but recommends damping the Grado and other cartridges without internal damping.
Ok - you piqued my interest, and I had nothing to do, so I played around with the damping in my arm. It is the 10.5i that I just installed on my Superscoutmaster which had previously been a 9 Sig. I have a Benz Micro Ebony LP, and discovered that a bit of the damping fluid is a good thing. Pull the plug on the arm and remove it to a very safe place. Clean out the will with a Q-tip as suggested in the instructions. Fill the well about 1/2 way. Too much oil will deaden the highs. Its easy to put in the oil - just add drop by drop - it fills fast. To remove oil, mop up with an additional Q-tip. The results are improved midrange - more depth and air between the notes, and improved low bass. Post your results.
OK, I tried dampening the arm last night and didn't like what I heard. The sparkle left the music. I read that Harry said if the cartridge was damped then not to damp the arm. The Dyna 20XL is damped.
Would've got back on this sooner but have been out of town. Thanks for the response Stringreen
12-22-07: Stringreen
I...discovered that a bit of the damping fluid is a good thing. ... Too much oil will deaden the highs....The results are improved midrange - more depth and air between the notes, and improved low bass. ....
A couple months ago I added the KAB fluid damper to my Technics SL1210 M5G, and that is EXACTLY what I got. When I first filled the trough about 2/3 full, the presentation was quieter, but it was also deader, with initial transients and high treble info missing. I lowered the fluid level in the trough to about 1/3 and voila! Magic!

I got the same improvements you mentioned--improved midrange, more depth and air between notes (especially noticable in better stage depth and decay of notes), and improved bass.

It also tracks like a mo-fo. Hideously warped records don't phaze it at all.

So my conclusion is that a *little* damping is an improvement over no damping, but too much damping (and you'll know it when you hear it) sucks the life out of the music.
FTR, I thought about trying less fluid. I thought it may have been over filled. But there was no fluid on the underside of the JMW-9 arm when I took it off of the pivot. That made me believe that there was not too much fluid. The trough was about 1/2 full. I may try it again. I've got lots of experimenting going on right now. So far I've tried 4" maple platform with the Super Feet and a sandbox without the Super Feet. I'll post some results when I have something more definitive
Artemus_5..try the Gingko platform under the VPI. Check out their website. Vinh the owner is extremely nice and very helpful.
Thanks for the recommendation Stringreen. I've heard good things about the Gingko. Many also recommend the sandbox. However I have found that the benefits of the SB are highly dependant upon the platform material that is used atop the sand. I tried MDF and that was too much damping. I found that Travertine tile was a good material to use. It livened things up and gave better definition throughout the spectrum. It worked well with the ScoutMaster with standard arm. I started to play with Maple as well, thus my 4" platform. It didn't work as well as the SB but that was while using the std arm. My next project will be to try maple atop the sand of the sandbox, which I have heard is the best of both worlds. I am a woodworker so I have the ability and tools to do the projects.
I should note that my sandbox is a 2 piece unit with a separate box for the motor. I have talked to Harry at VPI who liked the idea very much. FWIW, he suggested that I remove the rubber feet from the motor and replace them with machine screws. He said it would improve the sound, but I can't say that I have heard any difference.
Artemus_5 i experimented with the motor on my aries 3 and found the best was putting isoblocks split in half under the motor. i use three.
in my case a 2 inch maple platform with brass triplepoints between TT and platform and isoblocks under the platform to my rack. smooth frequency response top to bottom no smearing and crystal clear highs. of coarse YRMV.
on damping i like mine without any. it deadens the music to much for me even a small amount.
from what i've read above you are into finding what works for you by trial and error just like i have.
good luck
I've experimented with damping with my Scoutmaster/20 XL, and found that about 1/3 full(maybe a bit less) is beneficial. Too much, as has been pointed out, isn't good, but for me, a bit is better than none.
,,just for your edification..the Gingko platform is in 2 pieces with the table itself suspended, but the motor not.
Sberger, I tried just a little fluid and there was some improvement, most notably in the bass. However I'm not sure if there was some trade off with other areas ie the airiness. I must also note that the table is now sitting on the sandbox with Travertine platform atop the sand. It also has the stock feet. Whereas when I tried damping the arm before the TT had the Super Feet installed and was mounted on a 4" maple slab. At that time there was an airiness to the music that was quite nice. The bass was there and deep, but not very well defined. Now I have defined bass but have lost the airiness that it had before. So I'm not making a good comparison as yet. But it does show that good results are available using the damping fluid.

Stringreen, Thanks for the info on the Gingko. I was not aware that it was 2 piece.

Stltrains, I am going to order some isoblocks today. This has been the plan but haven't had time to do so yet. thanks for the info.

I haven't had time to do much listening in the last couple of days, but I do now have the maple top for the sandbox. I'll be experimenting with it over the weekend. Thanks to all for your info and input.
I'm a long term TNT/JMW-10 owner. The issue of damping is very cartridge dependent. In general the high compliance catridges like the benz and the grado's benefit from some damping. Low compliance cartridges do not. When I had a grado reference I had the damping trough about half full. After I upgraded to a koetsu jade, a low compliance cartridge, I use no damping. The dynevector is a low side of medium compliance cartridge thus it may or may not benefit from a small amount of damping. You might want to try just a few drops of the damping fluid in the trough and compare it with no damping.
12-31-07: Artemus_5
FTR, I thought about trying less fluid. I thought it may have been over filled. But there was no fluid on the underside of the JMW-9 arm when I took it off of the pivot. That made me believe that there was not too much fluid. The trough was about 1/2 full.

I suppose that if there is no fluid on the underside of the arm - the part of the bearing in the arm wand -, then there has been no damping going on at all. I had the same experience. I'd say everyone who fills the well 1/3 or 1/2 should check out if there is any fluid on the bearing on the arm wand. If I have understood HW right, you increase/decrease damping with the screw on top of the arm wand.

Best
Please be more specific about the adjusting screw for damping. I find no mention of it in the instruction manual, and don't see one one my arm, although mine in a 10.5i which very well may be different
On top of the bearing on the arm tube (when you look at the arm from above) there is a hole with a screw in it. This screw will lower or raise the top of the bearing inside.

No metion in the manual, that is right, but this is what I've been told by HW at VPI.

"The center screw in the top of the armwand adjusts the damping level. Clockwise from the top and you have less, counterclockwise and you have more. Don't drop it too low as you need clearance for motion."
Parelius, I just looked at the arm and I see the hole you are talking about, but I cannot see a screw inside. Now this may be due to poor eyesight, but I tried the two hex keys which came with the table and neither fit anything inside the hole. What type of tool is used to turn the screw?
It's a screw down there! No, the hex key is not supplied (VERY strange, indeed), so you have to buy it. Don't remember the size, and I'm not home this week, so I can't check it out. VPI should know.
This damping thing sometimes makes me wonder. I've had three different armwands (2 x 9" Signature and a10.5i) and also put up the 12.7 arm for my friend. None of the arms, as they came from VPI, experienced any damping when the "cup" was half full. Mostly 2/3 or more. I suppose most arms are like that. Very few know about the screw on the top. Strange thing is, everybody seems to experience differences, even though I'd bet most of them had no damping even though the cup was 1/2 full. You have to check - as Artemus_5 did - that there is damping fluid attaching to the part of the bearing on the arm wand.
I have the 10.5i on my Aries 3. The hex key size is 5/32. I agree with the statement above: "The center screw in the top of the arm-wand adjusts the damping level. Clockwise from the top and you have less, counterclockwise and you have more. Don't drop it too low as you need clearance for motion."
When you go too low the arm wand will hit the arm base pillar, don't let that happen. I was using an old Audioquest B100 cartridge previously I determined I did not need any damping. I installed a Audio Technica OC-9 yesterday. I believe this cartridge needs some damping. The sound is wide open and detailed. I think the stylus has some "jitter" while riding in the grooves. More after I try adding some damping.
Bill
I just installed my Signature9 on my Scout late last week. Great deal of improvement over the JMW9. The instructions that came with the arm said to use little or no fluid. I'm a bit of a rebel, and like to experiment, so I filled the well about 2/3 full. Thought it sounded a little better. I didn't know until I read this thread that you can raise or lower the pivot bearing to change dampening. When I lifted the arm off the pivot, I noticed no fluid on the bottom of the ring that is supposed to contact the fluid. So, I filled the well the rest of the way up. Checked for spills due to over filling, (ok) spun some vinyl, and that's when the magic started. I'm using a Dynavector XX2MKII, and now I am crazy in love with this table, arm, and cartridge. This now sounds like the way I thought vinyl was supposed to sound.
If you have the XX2MKII, fill 'er up, and see what happens. It works for me.
Thanks, and enjoy!
Dan
Harry said that it is true that damping could be adjusted by that top screw, however, it is real easy to screw up that adjustment and therefore it is not intended for us owners to screw around with it.
How can you screw it up? As long as all the other measurments such as vtf, vta, etc are in order, adjusting the top screw should be fine.