How important is VTA?

How important is VTA? I fitted the Ortofon MC3 to my P3 yesterday and as that deck has no provision for adjusting VTA, the arm is up slightly at the back. Also the cueing lever doesn't work. I'm not particularly bothered about this as it sounds great, but might it not sound even better if it was the right height?
So here's an idea. I get some of those plastic/fibre washers plumbers use and build the arm height up till it's right. Are there any proper fixes for this problem? They'll be more expensive right?
So will my idea work?

 

Rega sell spacers, in 3 different widths. A Rega dealer should be able to work out which one you need.

IME the importance of precise VTA varies with cartridge. My Rohmann was pretty fussy, I could hear when it was off, the previous cart much less so. In any event, I just set it so it sounds spot on on a standard pressing, I don't bother to adjust it for audiophool 180 gram pressings and the like.

If you want more precise adjustment, several companies make adjustable sleeves for Rega arms, have a look on hififorsale.com.

-- Ian

 

Changing the VTA you may hear a difference depending how sensible your system is and especially how much details it reproducs.
Normally when you raise the VTA (raise the rear of the arm) the highs will get better but too much will lose the bass. When lowering the VTA the bass will get stronger but too much and you will lose the highs.
The VTA must be adjusted very slightly and the results also depend on the record type. Especially the position for the 180g reissues differ from the normal LPs. When changing the VTA this might also affect the other variables (f.e. tracking force).

 

IME changing VTA only changes the sound balance, and doesn't affect the fundamental way a system plays music, if that makes any sense. I've experimented with a few cartridges and whilst changes of even very small magnitude are audible, I think it's a case of setting it to a sound you like and then getting down to listening - the idea of changing VTA for every thickness of LP drives me nuts, which is part of the reason I've never bothered with it. Each to their own I suppose...

 

I think that whatever you do it will always be wrong. So don't worry about it.

IIRC there are two issues, the Stylus Rake Angle, which is about the alignment of the stylus with the groove, and the Vertical Tracking Angle, which is the alignment of the generator assembly with the groove. The relationship between these two for a particular recording will depend on the lathe that was used and the characteristics of the vinyl. The relationship between them for a particular cartridge will depend on the manufacturer's specification, tolerance, the arm height and the tracking weight, but I think changes to the latter cause very tiny changes to the figures that matter.

Now I'm beginning to run out of memory, there was a very good article by Keith Howard in HFN recently with numbers and standards etc that would be worth digging out for those interested.

Paul

 

That's quite a good way of looking at it. I think the only problem is that the arm lift lever doesn't work. But I'm sure I can get used to that. It certainly sounds fine

 

As far as I'm concerned, the Stylus Rake Angle (SRA) is by far the most important area of tonearm set-up. Changes of even 0.5mm have made very significant differences to my ears, and these are the important differences since they are musical in nature. I've heard SRA out by only a couple of mm and make an entire system sound dull and lifeless - set it correctly and the system begins to live and breathe as analogue should.

Has anybody used the Clearaudio 'Pivoted Tonearm Alignment Gauge'? A friend of mine has acquired one and has been checking lots of people's turntables with it and hasn't found one SRA to be absolutely accurate - apparently the average error is around 2-2.5mm!! Mine was only 1mm and when corrected made a very big difference. Check it out at www.clearaudio.de/res1/en/index.html It's under the products/phono accessories section.

 

How does the Clearaudio device measure SRA?

And more to the point, what is 'correct' SRA?

Paul

 

Apparently it's all to do with measuring the precise distance (on the horizontal) between your tonearm's known centre of gravity and the stylus point, which is essentially the distance from the pivot point to the stylus. If you've got the manual for your tonearm, you should be able to find this figure, which means you know the EXACT measurement required before you begin. The Clearaudio device can very accurately measure this distance, and when set up at the correct length (it is adjustable) for YOUR tonearm, your stylus should drop perfectly into the centre hole on the alignment tool. The problem with most protractors is that they basically work by eye and are not precise enough, whereas with this tool there is (apparently) no margin for error at all, your stylus either drops into the hole or it doesn't, and if it doesn't you need to re-adjust your tonearm until it does. I think this is the best device currently available since it works from the precise measurements of the tonearm in question, rather than from an essentially 'fixed' position alignment protractor - as my friend put it, you simply can't cheat with the Clearaudio. Certainly since we used it to correctly set-up my tonearm I've been enjoying my hifi that much more - the immediate improvement was obvious and felt so 'right' musically.

 

I think you are talking about something different here Mr C. This device does nothing to adjust SRA

 

Hmmm...I did read it back to myself and wondered if I mis-interpreted what Paul meant by SRA. Apologies if I have (and I probably have!). So what is SRA then And what is the correct term for what I'm describing? Zenith, azimuth etc, all Greek to me.

 

Hi Mr C,

I think that the Clearaudio device measures overhang.

SRA is the angle of the stylus in the groove. The VTA is the angle of arc of movement of the stylus in the vertical plane.

Here's a diagram that may help.

http://www.theanalogdept.com/effective_length.htm

Also look here for more word on the terms involved.

http://www.users.nac.net/markowitzgd/cartalign.html

Adjusting the SRA will alter the sound. For the nth degree, you could change this for each record. This in most cases is too much mucking around. But there are some arm & turntables that allow adjustment while the record is playing. (VPI & Townshend Rock Reference master allow this). Most tonearms, any adjustment has to be done when you are not playing the record.

It is best to set by ear using a few records to get a good overall effect for good overall enjoyment.


SCIDB

 

Okay, I get it! I think that I can now confidently say that the Clearaudio device sets the overhang and the zenith (is this also called offset?). If I'm not mistaken SRA could also be described as Vertical Tracing Angle - if we agree that TRACKING is what the tonearm does, and TRACING is what the stylus does.....but having two different VTAs would be far too confusing I suppose!! Cheers for the links SCIDB.