end of side distortion

[phonomac]

Hello all,
I've looked extensively at alignment options, using the tools at VE, and have concluded that a better set-up can be achieved using a minor tweak to the standard Technics alignment.

If you increase the overhang by around 0.6mm, retaining the spindle-pivot (which is fixed for the standard arm) and offset angle as standard, you will have slightly higher levels of distortion on the outer portion of the disc, in to the outer null, but from then on inwards on a par with or substantially better than all the 'standard' alignments.

Using the Conrad Hoffman template generator, with a reasonably high resolution printer (inkjet or laser) you will have a template with a very fine line for the arc. I then laminated mine, so with a smooth surface you can allow the stylus to contact the template. With this setup you can very clearly align the the stylus to within 0.1mm - you don't need to estimate 0.1mm as a error, you just need to look at deviation from the arc which you can assess as fractions of the line width.

regards

Angus

[Qwin]

I tested the protractor I drew up this morning and it works great.

Used an Ortofon 2m Red (Elliptical stylus) and a Goldring 1042 (Gyger S fine line stylus).

Run them on several LP's and concentrated on the end tracks. It works well with no sign of ESD.

I have also written instructions on how to use it for those who are new to cartridge alignment.

Should appear in "The Knowledge" soon

Tried overlaying it on the Stevensen using DIN standard for inner grove radius that I plotted off the Conrad Hoffman program - there is a very very small difference between the two.

[serendipitydawg]

"Should appear in "The Knowledge" soon "

Did this ever happen? I had a cursory look and couldn't find it.

I found this thread via Google because I want to set up one of two SL1200's abandoned in my spare room by my son, as a dedicated mono turntable.

[Qwin]

Well if it was put in the knowledge, its not clear to me how to find it.

So here are the links to the instructions and protractor PDF I drew and which are held on my website.

http://www.jkwynn.co.uk/Pics/Instruc...Protractor.pdf

http://www.jkwynn.co.uk/Pics/Technic...Protractor.pdf

Hope you get a good result

[serendipitydawg]

I've bookmarked this thread & will print out the protractor & align a cartridge over the weekend.

Not sure what it'll be yet; a hot favourite is a pristine Grado F1+ I found in a box in the attic recently.

I will report back in due course.

Thanks again

[walpurgis]

I've mentioned this before. Be careful printing protractors, they don't necessarily come out quite to scale, rendering them useless. Try and find one with dimensions shown so you can check once printed.

[Macca]

I can't see mono makes any different for a stock SL1200 you need the technics alignment gauge to get it spot on. It doesn't use any of the standard versions.

[Qwin]

The instructions cover checking the size the template prints at and there are fixed dimensions I added to check against.
There is no protractor for the Technics, just the one I drew. Technics do not use any of the usual alignments, they use their own.
This is why I went to the trouble of making one.

The plastic gauge is crude and does not take into account any of the numerous elements that can be out of alignment and give a false result.
All the plastic gauge does is set the stylus relative to the arm and not the record which is what counts.
A protractor gets the stlus to the right location and at the right angle regardles, you could even get a good alignment with a slightly bent arm.
This is why I prefer this method.

[Macca]

But assuming the arm is 100 per cent the gauge should be all that is required shouldn't it? I mean the location of the record is a fixed parameter.

[Qwin]

The record is the ONLY fixed parameter, subject to centre hole accuracy of coarse.
Just look at how many components and mechanical joints lie in the cartridges location.

Is the pivot point and the screw fixings for the VTA assembly in the right place?

Is the multi part pivot assembly concentric with this?

Is the plastic yolk that accepts the arm tube true and is the tube the right size/angle to fit?

Is the arm tube true, I had three and they were all different to a very small extent?

Is the Head shell connector mounted true in the arm and does the Head shell washer compress uniformly to keep the headshell true to this?

I think you can see why I worry about this method, there is a massive tolerance stack and opportunity for error, more angular than length, though could be both.

If everything is perfect the plastic guage will work, but there is no way of checking, short of using an alignment protractor to confirm it works, and that would have to use Technics geometry.

You could bend the the arm at a right angle in the middle and still line the cartridge up with the plastic guage, but it wouldn't be correct.
It's a basic tool for Joe Average to use when he first gets his turntable out of the box, thats all it was ever intended for.

Far easier just to use my protractor which uses Technics geometry.