@nandric
So you think if you lose an argument on an audio forum, then no-one will hire you as a lawyer. Perhaps some of your recommended reading on philosophy, reason and logic might need to be revisited.
A new way of adjusting anti skate!
At the risk of death by fire, I venture into this conversation as you both have points that are correct and some that I would address differently. There are many factors that cause skating force. Even a pivoted linear tonearm experiences skating force - albeit in both directions depending upon the playing radius and at a skating force at worst case at about 40% what a standard 9" arm would experience. Offset angle has nothing to do with skating force. You can watch my very quick and dirty videos showing this to be true HERE. (It's not terribly professional and I'd demonstrate it differently today but who has the time?!) However, because offset angle is directly related to overhang, one would be excused for being confused on this issue. Yes, underhung arms will exhibit skating force too, but the force will be in the opposite direction! We should make the delineation between linear groove velocity (which I don't think mijostyn was talking about) and groove amplitude which is measured in velocity (usually cm/sec). Some firms describe this in microns where they measure the distance from the peak of the groove undulation to the centerline. Thus, Ortofon's 80/90/100micron torture tracks are actually double those figures in horizontal travel. A Lyra stylus is only about 100 microns wide. Think of the total excursion at frequency! That much velocity is unhelpful as a test track, IMO, and will cause too many unnecessary returns of cartridges to the manufacturer. Make sure you download the attachment at the bottom of the article mentioned above. Skating force is determined by the Effective Moment Arm and the coefficient of friction between stylus and groove. Both are required to create a skating force. As you can imagine from the drawings in the download, Effective Moment Arm exists in pivoted linear trackers too. The blank record method is highly variable based upon many things such as: radius test is done at, types/quantity of plasticizers in record, profile of VERY tip of stylus, zenith error, etc. We have all the equipment to do coefficient of friction testing and intend to write the first publication on this since the 1960's, but zenith error studies come first as they are more impactful on sonic performance than confirming modern vinyl formulations and stylus tip profiles have substantively changed the recommended setting for anti-skating. HERE is an interesting experiment in friction. Following a translation, we were able to calculate that ~10% of VTF is still the right target for anti-skating. The test needs to be more robust to be sure. Stay tuned for that... |
Thank you. The method in my video is a starting point and most it is ok. I also measure distortion with Adjust+ on each channel and phase identity. To measure the as-force out of the groove i test this https://www.briefwaage.eu/shop/my-weigh-jim-federzugwaage-stiftwaage-5g.php |