Dynavector XV-1s and JMW 10.5i question

How many hours have you put on the cartridge. It could be that the cartridge is either still breaking in, or, after break-n, the tonal balance has shifted in a direction that you don't like. The shift in channel balance could be the result of the antiskating now being less than ideal following break-in, but, it still seems a bit hard to account for such a shift.

During and following break-in, a cartridge's tonal balance can change quite substantially. If the bass response takes longer to develope (a common break-in phenomenon), the impression of less "air" (i.e., less high frequency emphasis) could be the effect of a bigger bass response.
After the cartridge has settled in, you can try adjusting the VTA and/or loading of the cartridge. Raising the tonearm pivot (tail up) slightly to increase the VTA can restore some of the "air." You can also get a similar effect by changing the cartridge loading. You should try a higher value loading resistor (meaning LESS loading) to get more "air." For example, if you had loading set at 100 ohms, try 150 or 200, or even wide open (47k ohms).

Philb7777,

Unless your cartridge is taking an inordinate amount of time to break in, it is pretty hard to account for such a significant change in sound for the worse. Since you haven't been fiddling with the adjustments, aside from trying the setup without antiskating, it doesn't seem to be a setup issue.

By the way, I disagree with the statement that your friend's use of blu-tack on the antiskating weight is silly. Your description of his use of a test record and determination that more antiskating force was needed based on higher distortion levels in the right channel IS one of the better ways to set antiskating. Your friend appears, to me, to be a very valuable resource in ferretting out your current problem.

There is a possibility you have a defective cartridge. Perhaps, something in the suspension has gone bad and the coils are no longer aligned properly causing the channel imbalance. I hope that is not the case. I am assuming that the sound has not changed when other sources are used (thus limiting the possible problem area to the phono gear, including the phono stage).

I agree that antiskating might be an issue, but, Philb7777 reports that sound is unchanged when the antiskating mechanism is completely disabled. My own experience with antiskating adjustments on other arms (Vector and Graham arms) is that much less compensation is needed than what is usually recommended.

The image shifting and changes in the density of the image is a bit hard to understand. Both could be the product of an increasing channel imbalance or if there is a problem with channel separation or poor interchannel phase relationship. All of these could be the product of some kind of misalignment of the generating elements of the cartridge (a defect in the cartridge). It might pay to contact the seller/manufacturer for help as early as possible to preserve any rights you have to getting this corrected on their dime.

Doug,

I hope you are right. I too thought it was a break-in issue, but, with the number of hours involved, the change in sound quality should not be that dramatic. I hope that the Dynavector is indeed a difficult to break in cartridge and that a suspension failure is not involved.

I somewhat disagree with you on test tracks. I use test records with musical tracks that are recorded at increasingly higher modulation levels (Shure obstacle course records) to set VTF and antiskating. The music is monophonic, making it easy to compare how the two channels are behaving when mistracking starts to occur. That is, essentially, the same approach you are advocating in setting VTF using difficult to track music. I really don't have any regular records that mistrack in such a usefully progressive manner as with test tracks.

Doug,

I agree it can be a break-in issue. It can also be the listener changing his perspective. Sometimes one gets into a hypercritical mode of listening and will then hear all sorts of things going wrong.

I don't myself fiddle with VTF. My arm (Basis Vector) is extremely difficult to adjust when it comes to VTF. Your use of whatever LP you are playing for adjustment would mean you are listening to something other than mis-tracking, unless you run your cartridges very close to the edge. I don't come close to any kind of obvious mis-tracking on all but a handful of LPs. What you are talking about are very subtle cues being detected by highly trained listeners who must be familiar with all other aspects of the particular system. In short, it is not an approach for a basic setup by someone who is somewhat of a novice. I agree that fine tuning a system is ultimately done by listening to regular records.

Have you used test instruments, like an oscilloscope, or the computer-based systems, like that produced by Feickert? I once had a shop check out my table. They thought my azimuth, which I set by ear, looked a bit off and so they used a test record and an oscilloscope. To their surprise (not mine), I had it dead on the money. I am wondering if test gear can be a fast and reasonable approach to setting something as subtle as azimuth.