Cartridge Alignment to Protractor Extremes

The overhang does look off in the pictures you posted, it's a little too much now so isn't following the arc from end to end. Minor adjustments to the alignment really shouldn't have quite the impact on sound quality that you outline above, at least in my experience, though I know some here do proclaim night and day differences with these minor adjustments, so I'm not saying my experience is the correct one

Did you restore the anti-skate after the adjustments? Clean the stylus?

 

It is really close on the arc and I adjusted again after posting those pics to get it even closer. Here is a question, though.

The premounted cart was a sukimo rainer. It was mounted close to what I would say is the center of the head shell. I swapped carts to a goldring E3 MM and mounted it in approximately the same location on the head shell and aligned to the null points of the DBsystems. The Eroica cart I mounted similarly - same basic location as the two previous carts and aligned with the null points on the DBsystems. When I printed the Conrad Hoffman template it was clear that the mounting location of the Eroica was way off relative to the arc - hence my tinkering with the alignment. Are the two carts I mounted that different from the premounted sukimo to necessitate such a significant change in position on the head shell?

 

I don't know about the others, but the Hoffman protectors have a suitable target sizing.

I'd suggest anyone at least try that method before spending anything on a protractor.

The other advantage being you can alter the alignments and print protractoes for a few cents each.

 

I don't know, you'd have to compare the stylus to mounting hole dimensions, it varies a lot among all the different cartridges.

Maybe the data being fed into the CH protractor is inaccurate, you should really try to measure the pivot to spindle distance if it isn't coming out correctly, or measure the overhang or effective length with the original cartridge and mounting position if you think that was aligned correctly.

 

Yea, I think maybe we are trying for a little more precision than may be needed, how many people actually measure their tonearm pivot to spindle distance with that kind of accuracy? Most probably just use the manufacturer specification, which can be off substantially. Below are some shots of my alignment using the CH protractor, thick lines and all, it is still pretty accurate ... not sure I could really do any better with skinnier lines, but I'm not one that frets much over these things and I go through the process fairly quickly and not often. I think whatever works best for a person is the best method, the main thing is to understand the basics, and the reasons behind the chosen alignment methodology.

 

Thanks. Was looking at vinyl engine calculator pro for comparisons. Initially thought calculations were off but they are not. Will tinker some more this evening.

 

The Vinyl Engine alignment calculator uses the same equations as the Conrad Hoffman protractor, so you will get the same results if you select the same input parameters ... below with 200.5 mm pivot to spindle distance and DIN inner radius ...

 

if is accurate it could work. i see the runway lines for aligning the cantilever are a little weak, bold lines are nice to have.

 

never worked for me either. tried one when i first got my 1200gr and the alignment sounded poor. even using the diving board was better.

 

You also need to consider the length of the cantilever, which also varies from cartridge to cartridge and will affect the alignment. Just measuring the mounting hole dimensions misses this variable.

 

I pretty much go bonkers just trying to get things properly aligned to one good protractor that I’m familiar with. Trying multiple methods at one sitting is a bit too much for me.

 

The stylus is on the end of the cantilever, so the stylus to mounting hole dimension is the variable we were discussing, but maybe I don't understand your comment.

 

I thought I had this sorted out, but am still trying to get a handle on alignment. Let's say I go back to align the cartridge with my DBsystems protractor. With enough cartridge placement room in the head shell you should be able to set cartridge alignment at different places along the head shell which would be at different values of over hang. Is this correct?

 

With the DB Systems 2-point protractor, you should only get perfect alignment at both null point grids with one specific value of overhang and one specific value of offset. Those specific values would be determined by the tonearm pivot to spindle distance and the geometry used on the DB Systems protractor. We previously determined that the protractor uses the Lofgren A alignment with IEC inner groove radius (Cartridge Alignment to Protractor Extremes ) based on the null points. The spec for your Pro-Ject tonearm is 200.5 mm pivot to spindle distance, so you plug in those numbers and get the projected overhang = 19 mm and offset = 25.2 deg with the DB Systems protractor.

That said, it is very difficult to determine perfect alignment at the null points without visual aids and experience, so yes, you can set the null grid alignment at different overhang values and they may look very close to perfect, though should only be perfect at that one specific overhang and offset value. Your custom alignment with the "wrong" overhang may sound better to you over parts of the record, that's entirely possible, or maybe even over the whole record.

The cartridge alignment is just applied math, and should produce the lowest distortion and tracking error, but there are many other variables when playing records

 

Where/how do you get this measurement?

 

Yes, if you move the cartridge forward in the headshell and don’t change anything else you increase the overhang.

If you use the Db Systems protractor correctly and get a good sounding result, I think you should leave it alone and get some sleep!

 

I think its very unlikely that an incorrect alignment (i.e., “custom”) will sound better than one of the well-known and researched alignments. Applied math does reflect the real world, if its done correctly. And the correct alignments and the lower distortion they provide can be verified with math, instruments, and ears.

 

Handy tip for Mint users with removable headshells.
I use the Mint, and as Avanti suggested, align to the extremes. This is really a PIA, but the results are definitely worth it.
I take the headshell off and use one of the Technics plastic gauges to measure the stylus tip to the back of the rubber washer.
This requires adding a second slot in the gauge, opposite of the one on top. Just insert the headshell to the BACK of the gauge and measure.
On my DP80 I get 55mm.
Then when I add a new cart to a spare headshell, I just install the cart to the 55, and I’m usually so close, that it reduces a lot of the fiddling the Mint requires for the overhang adjustment. Still have to align the cantilever though. Mine always leaves the cart twisted in the headshell slightly to the left.

 

nice tip.

 

Bought an eye loupe so I could better see and make adjustments. I have it sounding really good using the pro-ject specs and the Conrad Hoffman template. I have it well aligned to the null point grids, but it is off along the arc ever so slightly. The bottom of the arc through the arc mid-point is spot on. At the top null point maybe off mm or less to the inside of the arc. As move past the top null point the cartridge goes a little more inside. I can discern no sound quality difference. I don't think I can get it much closer adjusting by hand - what feel like small micro adjustments throw it off even more. The challenge for me is keeping the cartridge placement the same when adjusting the angle. When aligned along the arc, it is off a the null point grids and adjustments to the null points changes the position on the arc.

 

After reading all these posts I think I made a pretty good decision to buy a Technics SL-1210GR, mostly for its s shaped tonearm/detachable headshell design, making cartridge alignment to the Technics tracking error scheme, with or without supplied gauge, a relatively easy task, in comparison to fixed headshell straight tonearm concepts. My latest cart, an A-T VM540ML appears to be now aligned well enough to the Technics tracking error scheme that I cannot discern any tracking error distortion.

 

@Davey I completely agree, the error can regularly be several mm which makes a mockery of alignment gauges. I know this from using the Kinky (click expand on my post above) on numerous occasions - the pivot to spindle measurement is obviously absolutely critical.

 

My OCD kicked in and I ordered a Dr Feickert protractor. My previous alignment was using a Conrad Hoffman template that matched the specs of my tonearm - pro-ject x1 - 218.5 effective length and 18 overhang. Those specs are darn spot on for Lofgren A.

The Feickert aligns near perfectly for Stevenson with my current settings but off for Lofgren and Baerwald - would need to move cartridge considerably farther up in the head shell which affects sound quality. The Hoffman template with my tonarm specs calculates a 15.96 overhang. So the Feickert protract where I think things sound best is for Stevenson which according to Hoffman is not close to spec.

Am I doing something wrong?

 

I am not a fan of the Feickert protractor. It does not have an arc next to the spindle and introduces the possibility of too much error because of the required manual alignment to the tonearm pivot. In other words accuracy is in question IMHO.

 

Take a deep breath, listen to it as things are now, and see if it is an improvement. After that is the reason why you are doing this. Adjust, and then compare the sound again. Whichever one sounds the best is the one to use, after all that is what this is about. Now as far as the Feickert protractor accuracy being question, ummm that's "subjective" to be nice about it. These things take time, the Feickert is a great tool, but it has a learning curve. Set distance, adjust angle, move check adjust if necessary, move check adjust if necessary, then listen, listen and then listen some more. Don't fret be patient, it took me a bit to get the hang of the Feickert but I'm a high school drop out, so I have an excuse.

M~