Discuss The Viv Lab Rigid Arm

Hey all,

Another problem I am having with this discussion is the term 'distrotion' is being used way too generically.  I believe that the original use of the term by Löfgren etal was referring to THD caused by having a HMA (horizontal modulating angle) different than the HTA (horizontal tracing angle).  In his AES convention paper, Richard Tollerton digitally simulates errors of VTA and HTA in reproduced music and concludes large errors (beyond what an underhung arm provides) are required to enter the realm of audibility.  This is in direct contrast to my experiences and as far as I can tell Tollerton only considers the effect of the relation of the cantilever in the horizontal and vertical planes and like the pioneering work does not include the effects of incorrect SRA or Zenith.  

I find vinyl playback to be an inherently high measured distortion medium and any numbers predicted by the various alignment types tend to be of such a small comparative magnitude that much of this discussion is about the mouse and not the elephant it has trapped in the corner.

dave

@intactaudio 

If the mouse is distortions fromTAE, what's the elephant?

the elephant is every other thing about vinyl playback that obscures the ability to measure minor changes in THD as a result of TAE.  Attempting to assign an accurate and consistent FOM to TAE from THD has thus far proven to be an effort in futility.  An interesting addendum to this is how many people take the theoretical numbers rooted in the conceptual world and argue about the superiority of one alignment vs. another without a clue as to how their cartridge is actually aligned in the real world.  I think it can be summed up with my belief that if you have two null points on the record face then you have won and bet far greater than half of the folks out there do not have any null points.  For reference, based on the goal of an ideal Löfgren A a TAE of ±0.8° will push the null points off the playable area of a record.

dave

Dear @intactaudio and friends: The link you posted shows only that it’s the first time that that distortion was measured.

Rigth from the begin of the digital medium/CD almost all started to talk about the CD jitter and almost at the same time some of us started too to speak of anlog tracking jitter and not only that but between other audiophiles I started too to post several times through the years that trtuose cartridge ridding road named " Hymalaya Mountains " where the jitter and the Himalaya we just can’t avoid in any way: it’s main part of the LP/cartridge imperfections. Never was measured but it’s almost useless when not only each LP but each LP track measures different.

Well, those truly high distortions that are part of the " game " never were detected by us are just added colorations that we all like and that we can’t avoid.

The cartridge/tonearm alignments is something different that obviously does not measures those, the alignment only measures the additional tracking distortions as an effect in pivoted non LT tonearms and that’s why exist that overhag and offset angle. NO the alignments were not calculated to help with other issues as the off-centered cartridge stylus/cantilever because that responsability is of the cartridge manufacturers that need to way improve its QC.

Around 20 years ago I started to develop a " trusty " comparison whole proccess tests that through those years was up-graded/up-dated several times where I always use the same LP tracks that I know better than the fingers of my hands and I don’t use all the track because depending of what I’m testing msometimes I listen 20 seconds on one track and the like.

That proccess permits me to know what to look for and that’s why I can detect that overhang or offset-angle at some pointand some SPL. With out know what to look for detectionof those kind of distortions is to difficult to do it.

Btw, sometimes the alignment tracking distortions are developed at lower SPL that the one need it to detect it.

So all the satisfied VIV owners are " deaft " , ceratinly not and it’s not that their room/system has a poor level resolution. No, my take is that each one of them comparison proccess is not good enough to detect those alignment developed distortions. That’s all.

Btw, @lewm , the gentleman that did the analysis in your link posted there:

" Any arm not being designed according to one of these two approaches, produces higher tracking distortion than necessary and should be disregarded.  ""

Overall is an extreme complex issue.

R.

Raul, I saw his comment, too.  Let the author defend it.