end of side distortion

[richard l martin]

Hi. Can anyone recommend a protractor that will best help with end of side distortion please. I have an sl1200 mk2 with an at95 with a hyper elliptical stylus and i used an audio technica protractor. Thought all was good but i have recently noticed some irritating sibilant distortion on the last tracks. I just hate sibilant distortion! Thanks in advance Richard.

[Stratmangler]

Hi. Can anyone recommend a protractor that will best help with end of side distortion please. I have an sl1200 mk2 with an at95 with a hyper elliptical stylus and i used an audio technica protractor. Thought all was good but i have recently noticed some irritating sibilant distortion on the last tracks. I just hate sibilant distortion! Thanks in advance Richard.

Standard fit tonearm?
Could do a lot worse than this http://www.ebay.co.uk/itm/TECHNICS-S...item27d1655819

[Qwin]

Technics use there own alignment/null points.

The closest is Stevensen alignment using DIN value for inner groove radius, this is very close and gives values for offset angle, overhang etc allmost as Technics spec.

I had similar inner groove distortion, tried several templates until I came accross Conrad Hoffmans program for generating templates. It worked for me.

Find it here: http://conradhoffman.com/chsw.htm

Third item on list of downloads.

[DSJR]

End of side sibilant distortion isn't *always* just due to misalignment although HE and line contact styli are very fussy of setup - try adjusting arm height and tracking force as well. Original AT95E's track at around 1.8 to 2g and the special HE version may need at least 1.5g for all I know. I have a Shure M91-ED style replacement stylus and this isn't anything like as good on hf tracking as the original would have been - much lower compliance too..

My advice from a distance would be to investigate the next tier up, something like an AT120E which, despite not having such a fancy tip profile, should have greater tracking limits and a well integrated bass if fitted to a low mass headshell. If a posh diamond profile is your thing, the AT440MLa is also a good match in a later model Techie 1200 tonearm.

[Qwin]

I agree that there could be things other than basic alignment creating your distortion. I found the anti skate level contributed to the distortion as well so experimenting there might help. (presuming std Technics Arm)

Still think you need to start with basic alignment though, before trying elsewhere.

The Audio Technica Protractor you used is probably a Baerwald alignment which I found totally unsuitable using three different protractors.

Technics uses its own alignment and for a pivot to spindle distance of 215mm results in an overhang of 15mm and an offset angle of 22 deg.

Baerwald produces an overhang of 17.8mm and offset angle of 23.7 deg.
I am no expert but believe that is the main cause of your problem.

The Stevenson Alignment I sugested gives an overhang of 14.93mm and offset angle of 22.1 deg, I said it was close.

I used this and after a bit of additional fiddling with the VTA and anti skate on the fly, managed to find the sweet spot of my Ortofon 2M Red. My veiw of this cartridge has changed, I am now hearing what it can achieve for the first time and without any ESD.

I would try this first, it costs nothing.

[RobbieGong]

I actually prefer Baerwald and following the arc etc. Has always sounded good to my ears with the stock arm and now my Micro Seiki MA 202. Can someone remind me which protractor (Stevenson, Baerwald ?) jap arms are generally set to ??

[richard l martin]

thanks everyone i have taken all of your advice on board and will try a Stevensens protractor. I seem to have experienced these problems for many years and i am now considering a linear tracking turntable but i cant afford an expensive one. Would say a Technics one be better in terms of ESD ? Any one have any thoughts on this? Kind regards Richard.

[Barry]

The Technics SL1200 Mk II arm has the following geometry:

Length, pivot to stylus: 230mm
Length, pivot to centre of TT: 215mm
(thus) Overhang: 15mm

Offset angle: 22 degree.

The geometry therefore corresponds to neither the Baerwald nor the Stevenson prescription.

To minimise the tracking angle error, the overhang needs to be adjusted so tangential tracking is achieved at the two radial null-points 58.8mm and 113.5mm.

Cartridge/arm misalignment will affect 'end of side distortion' far more than incorrectly setup bias.

[Qwin]

Hi Barry,
you pretty much repeated what I had pointed out.
Trouble is there isn't a Technics protractor using their geometry. At least I don't think there is, never found one myself.

The Stevensen is within o.1mm for overhang and 0.1 deg for offset, all be it at slightly different null points.
I doubt any of us could set it up to that level of accuracy anyway and it would still be more acurate than the plastic thingy Technics made.

The trouble with the plastic gauge is it depends on the arm "S" bend being bent EXACTLY right - have you ever tried bending tube to that level of accuracy? Also that there is no error in the fitting of the headshell connector or thickness/compression of the complient washer. At least a protractor ignores all these elements and addresses whats hapening at the actual point of contact.
In the absence of anything designed for the job I think the Stevensen protractor is the next best thing and the one to use.

Boy am I glad I'm going to a linear tracker soon.

[Barry]

Hi Ken,

Yes, we are in close agreement; though the figures I calculate for Stevenson are 22.6 degree offset angle with 15.89mm overhang and for Baerwald 23.97 degree and 18.05mm. Similar to your values.

Agree bending the arm tube to precise angle, and allowing for relaxation is difficult. Apaparently Breuer observed the relaxation in bent arm tubes over several months - and then decided to abandon bent arm tubes for his own arm.

In my experience, the Japanese tend to "do their own thing" when it comes to pivoted-arm geometry, but in general the geometry they choose is closer to Stevenson's prescription than either Baerwald or Loefgren.

As is in all things audio, it is often best to let your ears decide.

Certainly tangential tracking arms are devoid this problem - but have their own shortcomings.