JMW9 setup tracking problems... need help


Hi,
After almost 20 years I decided to return to analog. Looking for a good TT, found here in Audiogon a VPI Super scoutmaster with JMW9 arm in perfect condition and decide to buy it. I follow all the setup procedure: first level the turntable; then lower to arm until is parallel with the plate (to get that I had to lower the arm up to its lowest point); use an arm load meter to set up the traking force(I use a Denon 103R cartridge at 2.88g; little bit high of its higher set up of 2.8g); and rotate the counterweight to get perfect lateral balance; and finally I use the alignment jig to setup the perfect placement of the cartridge in the headshell. Everything looks OK but each time that I try to play a record the stylus runs across the vinyl and jumps half a song or more and sounds are sometimes (not always) intermitent. In inner grooves stylus track better b ut not perfect.
Maybe this is a silly question but dont know what else to try (I recheck everyhting and all looks ok) and VPI is not open until the 7th and will love to spend this holidays enjoying this grate TT. Thanks in advance
jorsan
Check to see if you have twisted the wire that runs from the arm to the locking collet. Even a slight twist will create a very large bias force that will cause this.

It is probably exacerbated by the mismatch between the low compliance cartridge and the low arm mass. This is not a good match at all.
Check the anti-skate force which is provided by the twisted wire. First set the tracking force to zero by moving the counter weight away from the cartridge (opposite direction). Then move the arm close to the spindle and lower it. The force of the twisted wire should push the arm outwards to the edge of the platter. If it does not do so completely, unplug the connector from the junction box and untwist the wire once. Repeat the process. This should do the trick and not skip when playing records. Try a local dealer in your area. They may help you with the set up for a small fee.
Viridian and Sanji have stated the likely solution for you. Watch the twist on the phono wire.

I heard the Denon 103R playing just fine on a friend's Scoutmaster a few years ago. No problems at all. So, I'm confident you can find a solution with this cartridge on your VPI table.
.
Thanks guys for your fast responses. I'll try what you said and will post the results.
Agree with Rushton-the DL103 is not the problem.

*I previously had a Scout/JMW 9 that worked fine with this cart, and many, many others at VA have reported the same.

*The compliance of the DL103 is not as low as the spec sheet seems to show, due to the methodology that Denon uses to determine the compliance.

Saying that, you should buy the 15 dollar, 3-gram headshell weight that VPI sells-and see if it makes a difference in the sonics. Cheap experimentation.
Make sure the arm is clearing the lift lever platform. If you made an adjustment in height of the arm, this could be hitting the arm. You might need to lower this.
One other thing-be sure the wires connected to the cart are tucked up into the headshell well enough to clear the vinyl.
First of all, I found that the wire was heavly twisted and as a first step I untwist the cable to the point that each wire goes individualy, and the connector is not receiving any forze to any side. I have played a record again and problem persist, the only difference is that now the problem is confined just to the first 1/5 of the record, the rest seems to track OK but dosent sounds clean.

Sanji,
I've tried that and yes, if I push the arm outwards to the edge of the platter it returns fast so looks like all is normal here.

Johnbrown,
I have the 3grams headshell weight that VPI sells, do you consider that I have to add that? looks like the arm doesnt need it, the counterwheight is in the middle when I set up this cartridge.

Any other ideas? thanks
Can't find in the VPI Industries page who represents them in my area (Miami, FL.) so if someone knows that information, please let me know. Thanks
I just redo all the setup and now is working (I must have done somehting wrong the first time but dont know what was); will try it today and hope will have no more issues. Thanks to all for your help and if I have more problems will post them here. Again, thanks for your interest and Happy 2009 !!
"....looks like the arm doesnt need it, the counterwheight is in the middle when I set up this cartridge."

The purpose of the added weight has naught to do with VTF, but with tweaking the arm resonance relative to the dynamic compliance of the cart suspension. Since the DL103 is a relatively low compliance cart (though, as I said, not as low as it's specs makes it appear), you may see sonic upgrades by adding the weight (and readjusting the arm for correct VTF). At this point, however, if you've got the rig running, just enjoy some music. You'll want to establish a listening reference point before you make any changes, or do any experimenting. Though, were I you, I'd lower that VTF to 2.5 at some early point.

If you do want to experiment with adding weight to the headshell, and you've got an electronic scale, I'd suggest weighing out a blob of Blu-Tac and attaching it to the top of the headshell. That way, you don't have to remove/readjust the cart while you're experimenting. If you like the change, you can add the VPI weight for Handsome Good Looks.

And btw, congratulations on getting 'er going.
Johnbrown, let me elabore more about the VTF 2.88. The reason is that the manual recomends to go to the upper setting of the cartridge, in this case manual mentions 2.5g (+/- 0.3gr) plus 0.1 gr more. This is because they compensate with more weight not using anti-skating with this arm.
Hmmm...would you underinflate your tires to compensate for deficiencies in your autos suspension as well?
The JMW9 is not a low mass arm unless your standard is the 35 gram mass of some of the old Japanese arms. I am more worried that it is a little heavy for some cartridges. Tracking heavier is always preferable to tracking too light but don't overdo it. I use about 2.2 with the Denon 110 in same arm and intend to use around 2.5 when I get around to putting the 103 I recently purchased in my other JMW9 arm.
Viridian, its not me, is their recomendation, follow this link and open the jmw9 manual,there you'll find the explanation: http://www.vpiindustries.com/manuals.htm
Jorsan, I am aware of the recommendation, but you realize that VPI's recommendation is to use the cartridge outside of the cartridge manufacturer's recommended range. Let's look at this advice for a second. At first, it seems quite benign, you are only using the cartridge .1 gram over the maximum. I believe that this translates to only 3.6% over the maximum recommendation or 14.3% above the recommended force of 2.5 grams. Of course, there are obvious consequences to increasing tracking force, diminished stylus life, increased record wear and accelerated wear of the suspension. And I have no doubt, that these increases may be moderate in the context of a properly aligned system. Then again, by going past the manufacturer's recommendation you may be moving the coil out of the linear part of the magnetic gap. So, in addition to putting added stress on the mechanical damping system, you may no longer have optimal electro-magnetic damping of the moving system, as well. What other precision products would you use outside of the maximum recommendation from the manufacturer?

Personal experience using unipivot arms - and I hasten to add, not the JMW - that have no anti-skate - the Grace 704 and 714 as well as messing around with two other unipivots that I have owned, the Morch UP-4 and Audiocraft (Ultracraft) AC-300, without anti-skate, I can tell you that there is no need to increase tracking force to properly track highly modulated inner grooves without bias compensation. At least if the arm is correctly designed, and the effective mass and compliance are correctly managed.

There also seems to be some confusion about what constitues low, or high, effective mass in a tonearm. The JMW is in the range of 9 grams effective mass, without the auxilliary weight, which puts it within a hair of the Rega RB-300 as far as effective mass is concerned. Call it low, call it high, but it is much lower than the broadcast arms that the 103 was designed for, which generally exceeded 20 grams of effective mass. And, as a previous poster pointed out, the 5cu spec that Denon publishes is non-standard and implies that the compliance is lower than it actually is, but even at 12cu, this is a very low compliance cartridge. Denon even made a consumer version of the cartridge, the 103D, to address just this issue. It is considerably higher in complinace than the 103 and still is not a particularly good match to arms in the 9 gram range. The Zu 103 is specifically designed on the RB-300, which is why they add so much mass, in addition to the increase in rigidity. The TWL mod is a simiar attempt to increase arm mass to match lower compliance cartridges.

In the end, it comes down to a matter of how each of us hears. I purchased a Denon 103D new in the 1970s and a 103 sometime thereafter. I have used them in over twenty arms, and my personal observational experience is that they will track in pretty much anything, but they will not begin to sound their best until you are over 14 grams of effective mass, and they will not produce the full color that they are capable of until they are used in arms over 21 grams of effective mass. Your mileage may vary, and probably will. Again, if it sounds good to you, then it is good.
Thanks Viridian for that long, clear, and logic explanation and of course will try your advice. In the case of this specific arm, what cartridge do you consider can shows its best? maybe I can try it and compare.
How about not switching the arm, and just trying to increase mass to see if anything that I suggest holds any water, at all, for you? Search the forums here by putting in "TWL mod". This is a free, and reversable, mod that adds mass to the moving system, quite a bit actually. It takes a bit of messing around to get it right, but hey, I like "free" and "reversable". As another poster suggested, you already have the auxilliary weight, why not do a little comparison using this as well? The problem with analog, is that all of these things take so much time and patience. In digital land, you can just buy a new CD player. But, if you can devote a bit of time to optimizing your LP setup, you may really reap rewards. Also, search the web for Uwe cartridge bodies. Uwe makes a Panzerholz wood body that the Denon generator slips into that makes it more massive and more rigid. I believe that it costs less than $150.00. You may research it a bit.

Harry W. recommends Dynavector cartridges for use with the JMW-9 arms. The excellent 20XL has a really different sound than the Denon, but is completely competitive. But why switch if you are happy? Again, you are the arbiter of the goodness of the system. Not me, not the slide rule, and not Harry. Enjoy!
Veridian-

Nice response-analytical backed with experience. Though I've not tried the dl-103 series on 20 (!) arms, I do have some experience. I've got a couple of DL-103Rs, a DL-103, a 103r with VdH Type 1 cantilever and stylus, and a Zu 103r. My arms include a JMW 12.5, SME 3012, SME M2-12, SAEC WE-308, SAEC WE-317, Rega RB-300, and a couple of others. I agree that a higher-mass arm (I'm a fan of 12" models) are more conducive to the compliance characteristics of the 103-series, but even so my past experience with the JMW-9, with added weight, was very satisfying. Maybe not the absolute best that can be wrung out of that cart, but still-very good. Were I the OP, I'd enjoy the 103r through it's effective stylus life, and then try a re-tip with a more compliant cant. Were he willing to spend a bit more money, the Dynavector DV-20lo is a nice(er) match to that arm.

BTW, agree absolutely with your note vis-a-vis the VTF/AS relationship. I think the OP had advice that, at best, was well meaning but derived from a calculator, not real-world experience. As I said, I'd drop the VTF down to 2.5.
Note to Veridian-
My post above was written referencing your post *before* your one above this one-take that into account when reviewing context. Looks like we're pretty much in agreement.
look a dL 103 should track noproblem at all of the vtf's you tried, 1.5 to 3.0 something is wrong. Look at the pivot. Make sure it is not bent or damaged. Also look under the wand and make sure the bearing is ok, no cracks or something stuck, obstructing the pivot point. Start over. Try many records. Also question the Denon. Something is wrong. Take multiple pics as it is currently and send them to me or all of us. I will respond tomorrow morning. Its something.
Just drop the weight to 2.5g and seems that everyhting is working perfect now: cartridge tracks several LPs with no flaws so Im enjoying my TT at last!. In a near future will try the 3 gram headshell weight to compare.
Instead of modify the cartridge with the wood case option and the extra dollars that I have to expend on that, is not better to hear from you some recomendations of cartridges that can works its best with this arm? look, Im very happy with the sound that Im getting now but, beacause is not easy for me to compare with other opptions, your experience could help me to get the best of my new TT; the idea is not to compare this unit with others (IM not going to change this TT) but to hear recomendations for this expecific configuration. Lets assume a ceiling of one thousand to expend. Thanks
I'm with Johnbrown, problem solved, enjoy the darned thing and start focusing on collecting some nice music! And, above all, have a happy and prosperous New Year.
Hi Jorsan. Glad that you got the rig up and running. I have a Scoutmaster JMW9 and a Sumiko Blackbird. This cartridge works well with the Scout series tables and arms and is also one of VPI's favorite cartridges, I've been told by the manufacturer.
Viridan, you're right, problem solved and now to enjoy the music! thanks to all.
Sanji,that is one of the options that Im thinking but for now as Viridian said: "enjoy the darned thing and start focusing on collecting some nice music!" thats what im going to do.
Thanks and wish you all have a great 2009 !!!!!
Sorry guys but need some help again: since yesterday Im hearing a VERY LOUD noise that sounds like a gunfire when stylus tuches the vinyl or when I rise it from the LP, and sometimes happens also when record is playing. This sound is scary and Im worry about my speakers also. Do you have any idea why?, somethin g that I can try?
Thanks again in advance for your comments
Do you live in Watts? If so, then it is gun fire! Seriously, sounds like static electricity. Make sure that the arm is properly grounded to the preamp. Another thing that may help, if your air is very dry, due to heating your house in the winter, is to mix one part fabric softener to two parts water and spray it on the carpet around the installation, being carefull not to get any on your electronic gear.
Hi Viridian, I checked that this morning buy I will verify if the arm is properly grounded tonight. I live in Miami FL. so no, no dry air here. Hope the problem is not a broken cable when I untwisted the wire that runs from the arm to the locking collet. Will post my findings.
Thanks for your response.
Viridian, the day before yesterday called VPI and spoke with Mike, he told me the same: problem must be static charge so he ask me to run a cable from a big nub that is located at the bottom of the turntable to a ground wall outlet. Well I've tried that and doesn't work; I think (maybe Im wrong) the air in my house is not dry enough to create this kind of static problem so maybe you have other ideas that I can try. thanks
Jorsan, please try my suggestion, outlined above. It is virtually free and will take very little time to try.
Thanks Viridian, I verify that the arm is perfectly grounded to the phono preamp so I assuming what you want me to try is " ...mix one part fabric softener to two parts water and spray it on the carpet around the installation..." right?
After all night with some sprayed towels around the turntable (I have wood on the floor not carpet, so I decided to use this option), this morning I turn the TT and found that about half LP everything goes OK but after that the same "shots" starts again. One thing that Mike from VPI told me is that because the denon 103R has a plastic case promotes this problem. About a week ago I placed an order for a wood case from Europe (not for this reason but to add more mass to my arm)so will see if this solves the problem.
Hi Marty, first I have to let you know that static problem's solved: looks like the VPI's Mike trick do the job, I think this could be something related to the VPI TT design but anyway, now I have no static at all!.
About the wood body yes, I ordered from Uwe.
Thanks for your help and enjoy your weekend.
Jorge
Marty, sorry to bother you but need some ideas here. Today arrives the wood case so I decided to install my Denon 103r inside right away. I follow all the video instructions with all the possible care, recalibrate all the parameters, and finally put a record on my TT to find . . . one channel is not working !!!! well not at all: I can hear music but just when I put my ear very close to the speaker. Don't know what happens but I think the problem is the cartridge because if I switch the left and right connectors in the TT the bad channel switch side. Do you have any idea what happened? and, is possible to fix it? I do my best working with the Denon but .....
Just switched the 4 cables that goes directly to the cartridge (the 2 rights with the 2 lefts) and found that the problem goes from left to right so, this is a proof that the problem is not the cartridge but the cables ... am I right?
I think my laast post is wrong, what it prooves is that the cartridge is the problem. If Im right .... I have a serious problem!!.
Yes, the cartridge is the problem. Check the fine wires that run from the inside of the cartridge pins to the generator.

Feel free to contact me directly, off board, if you prefer.

Marty