Wednesday, March 20, 2013

Cartridge alignment joys

I've been trying out a couple of cartridge alignment gauges recently to celebrate the installation of an SME V on my table. The experience convinces me that those who find vinyl too fussy to deal with have good cause.

First off, in need of a new alignment protractor for the arm, I found that these are not  always readily available, and rather than buy one from the UK, I ended up dealing with the fine folks at Flat Earth Audio who were out of stock but told me they could get some from SME probably faster than I could. Deal done. At $18 shipped, this is never going to break the bank but given that you are only getting a piece of card with the devilishly clever SME design that allows alignment with single point adjustment, you cannot complain. However, from my perspective, there are still a couple of problems with this alignment tool.

On my SME 20, the centre hole on the gauge is larger than the spindle on my player, which was not a problem on my old 309 gauge. With the roomier hole, the placement of the gauge is never certain and either SME makes difference center hole sizes for different tables, or my older SME has an older sized spindle. The solution for this was careful placement of tape over both sides of the hole which I split carefully with an Exacto knife on two-diameter lines to allow me to center the gauge tightly on the spindle. Plenty of room for the anal-obsessive to worry that the diameter lines were not perfect but it worked well enough for me. Seems odd though that I am reduced to this.

Problem two is the degree of precision one can get using a single point that is determined by eyeballing the arm's alignment from above for placement within two lines representing the outline of the tapered tonearm. It is possible to move the arm slightly fore and aft while still getting the appearance of a good fit, which means that the stylus point also moves slightly without ever being certain that you have got it perfectly set. SME's literature suggests not to sweat it -- and that is probably the most appropriate advice here but surely they know who they are speaking to? Audiophiles live to sweat it! For the sane few, this is fine, but how many sane purchasers of multi-thousand dollar analog rigs are out there? So, ease of use is wonderful but the sense of precision one demands, especially with a table/arm combo as otherwise perfectly engineered as my SME 20/SME V, is lacking.

In search of alternatives (or could it be reassurance?) I have purchased the alignment gauge designed by AVID for SME arms from Analog Seduction in the UK whose price and service were very good. This arrived promptly and safely but you should be warned, the only instructions are etched onto the gauge. In form, it's a hard, mirror-like plastic, quarter-circle-ish in shape, which (incidentally) fits the spindle of my SME 20.2 perfectly. Good for several models of SME tonearm, it's almost impossible to photo clearly but this image from Avid will give you a good idea. Here are the instructions:

1. Point alignment guideline at tonearm pivot
2. Immobilise alignment tool
3. Align cartridge using one of the grid patterns
4. Without moving guide check correct alignment with other grid.

As one intrepid owner on an audio forum put it, it's easy from step 2 on, the problem is step 1. While the tool does allow you to sight down a guideline (unlabeled) toward the pivot point of your tonearm, if you can see it, the line does not go all the way, and in my experience, it can tolerate slight sighting errors which, if you can imagine the tool, means you would move it slightly left or right to get your fix. Of course, in so doing, move the position of the two etched alignment grids on the gauge. Small errors, perhaps, but variance in use that you'd obviously wish to avoid. In fairness, I've not heard to many complaints from other users, but then I've wondered how confident all of them are in their sighting?

I'd add another couple of potential problems here. When you go to step 3, do you lower the stylus onto the gauge or just above it? No instructions there but I lowered to the surface and noticed that if you really want to hit the target, minor movements become very important, all the more reason to get the tonearm pivot point sighting perfect, not just close. My solution was to run a taut thread along the line and across the top of the SME to try to ensure I hit the pivot point. It might get easier with practice but since the thread must rise above the tool to hit the upper pivot point on the SME, there is room for error here too. All this makes me think those expensive tools which contain an adjustable pivot to spindle element such as the Feickert, are not overkill; precision costs. Alternatively, stick with the SME paper gauge and 'don't sweat it'. More as I go.

1 comment:

Anonymous said...

Hi Patrick:

Just saw your post today in Jan 2021.

Your SME V alignment protractor did not fit properly on spindle because you were missing one factory supplied hardware, Record Spindle Bush. It is mentioned on step 502 in SME V manual.

Analogue Seduction also warns about it on SME V protractor page.

If you use Record Spindle Bush then the fit is perfect or alternatively you can use SME IV alignment protractor which has the narrower proper spindle hole.

After so many years of experience, what you you using these days? I was interested in Avid Protractor but you are right about guideline to tonearm pivot problem. Then Feickert Protractor comes to mind but SME V lacks indicator for pivot point on the top.