[bacobits1]

It was not the case here. All alignment was right on to the Guru protractor. Overhang and line adjustment. I did not move the protractor when measuring both points.
It sounds great and I did not loosen anything.

D

[Sonny]

Actually, it's more of twisting the body to align with the lines on the Guru protractor. It's not moving the cartridge backwards (thereby affecting the overhang and effective length, which you don't want to do). It's just a realignment of the cartridge squarely to the groove.

Bob

Hmmm...interesting...I know that the Guru suggests moving the cartridge back 1.27mm...and since you and Babbits didn't do it, I would probable say that the Guru method was not implemented, right?  Or am i missing something?

[BobM]

The Guru method aligns the body of the cartridge 1.27mm behind the usual alignment lines. It is not "moving it back" as much as it is aligning the sides of the cartridge properly using this offset.

Bob

[Sonny]

I am confused:
because here's what the instruction says:
The intersections of the two long radial lines with the central line of
the two parallel clusters (Green arrows) are the classic Cotter
intersection points at 66.0 and 120.9 mm from the center spindle.
But 0.05” (1.27mm) behind the Cotter points are the Guru points
(Red arrows) and these, which are not on any exact radial line from
the center, are the alignment points we suggest for the diamond to
rest and the cartridge then be twisted and/or moved back and forward
so it aligns with the parallels at both red arrowed intersection points.
I cannot offer any logic for this positioning, just strongly suggest you
try it. If you don’t like the result, then it’s no real work to revert to
the regular settings, and you now have those markings also

[BobM]

these, which are not on any exact radial line from
the center, are the alignment points we suggest for the diamond to
rest and the cartridge then be twisted and/or moved back and forward
so it aligns with the parallels at both red arrowed intersection points.

Exactly - just use this intersection point to align your cartridge instead of the regular Cotter points. The stylus should hit the exact intersection point at each location and the sides of the cartridge should align with the parallel lines. "Cartridge should be twisted ..." is what it says. Do what it takes to align the stylus so it hits both points exactly first, then twist the cartridge body so it aligns with the other lines. I actually found I needed to move my cartridge forward a smidge (not back) to hit the crosshairs exactly in both locations.

Bob

[Sonny]

Bob, I understand what you're saying regarding aligning the cantaliver, but I think the whole thing is to also move the cartridge (stylus) back 1.27mm as well, effectively reducing the recommended effective length by 1.27mm.

In anycase, I am glad it wors for you wonderfully.
T

[BobM]

Bob, I understand what you're saying regarding aligning the cantaliver, but I think the whole thing is to also move the cartridge (stylus) back 1.27mm as well, effectively reducing the recommended effective length by 1.27mm.

In anycase, I am glad it works for you wonderfully.
T

I think that is a bad assumption. You have to align the cartridge to the lines, regardless of whether that is moving it forward, backward or turning it upside down. Moving it back in the headshell does not accomplish that goal exclusively - it only reduces the effective length and overhang, throwing off the geometry requirements of the arm.

Try it for yourself and see if you can make it work that way. I couldn't, and actually needed to move the cartridge forward to align it to their protractor properly. Why not send a note to the author of the article and report back on your findings?

Bob

[Wayner]

OK, I downloaded the protractor and the instructions. There seems  to be a little background information that is not provided. I consider myself an expert on turntable geometry and well, They just don't get into it. Apparently, someone "The Guru" thinks that the overhang is too much and backed it off 1.27mm. OK. That's hoping the tolerances of where the arm pivot got put in the exact spot it was supposed to be from the spindle center. There is no real explanation of why the "guru" thought the move was necessary.

I'll agree that there is a very small window for alignment to get the sweet spot right, along with VTF, VTA, anti-skate and azimuth. If you have any of these factors out of whack, the thing is going to suffer.

The whole purpose is to find the proper null point locations and try and get your stylus into that position with the right offset angle. I personally don't think there has been a tool invented yet that will dial in perfection, tho I'm working on it.

Wayner

[Wayner]

Gentlemen, I just printed out the Guru alignment card. It has no reference points to measure to see if the print is scaled or not. Because of this, I can't recommend using this protractor and in my mind if anyone didn't think of this, they haven't got the rest of the thinking in order either. I'm very troubled by this and I'm not sure what the point of all of it is. Maybe they just want to collect email addresses. I'll investigate this some more later, but I am not in favor of this at all.

Wayner 

[Sonny]

Wayner,

That's exactly why I haven't used it.  I just know that the NP 1 is 66mm...other than that, when the instructions say align the cartridge as specified or so forth, I had no idea what they were talking about.  I think the Guru's protractor is really saying the following:


1 - Align your cartridge according to Baerwald or whatever method you use[/li][/list]
2 - By doing above, the cartridge alignment and effective length (Mounting Distance + OverHang) will be according to specification
3 - Once this is done, put the Guru Protractor on and align NP1 with the Green Arrows
4 - Then move the cartridge (stylus) back from Green Arrow Spot 1.27mm to the Red Arrow Spot
5 - Align the cartridge so that the body and cantileever is according to the grid
6 - They check with NP2 and should be ok at Red Spot.

T

[Wayner]

That is what I was thinking, and they just like to different null points. Not sure if all this is worth the effort. What we are all after is precision alignment. We know that record master stampings were cut in a straight line with a very precision cutting lathe, We also know that we are cheating, using an arm that follows an arc. Some of the angle of the arc favors the left hand side, then crosses the magic straight line, then favors the right side.

The first biggest problem with any cartridge alignment is verification. We assume that the tonearm to center pivot point is to specifications. If we can't prove that, there is no sense going onward. There has to be proof for the first step. Overhang and offset can be adjusted to suit, if we use the calculator to find the null points we desire. Backing the stylus off of theoretical just changes the position of the null points. There isn't any "magic window". There is just fairly accurate or out of the ball park.

Wayner

[BobM]

Yeah, I had a problem with a lack of scale also, but when I put my already aligned cartridge on the "normal" points on this printed Guru protractor they aligned perfectly. So if that worked then I considered it in scale, at least off of my printer.

I tried just moving it back the 1.27mm, but then it didn't align properly with the Guru spots in both locations. This didn't make sense to me, but that's the way it was. I had to play with it a bit to align properly on the Guru spots, and that resulted in moving it forward some on my headshell. I know, makes no sense, but that's what it took to make it hit perfectly in both locations. Which is why I believe the real purpose is to shift the cartridge alignment just that little bit inward and not to change the effective length.

What would be a good exercise is to go back to my original protractor and see how it differs now. That's a good idea, I'll have to check it out tonight.

I can say that it does sound good, but I can't say that there was any real difference over the original alignment since it took a while to get it right and my aural memory is not that good.

Bob

[TheChairGuy]

I'm with JVC on the subject of spot-on alignment. 

To quote from one of their manuals regarding this: "Errors within 1mm are negligible from a practical point of view"

It's relatively unimportant piffle next to the greater picture of dialing in other matters with vinyl.  It's certainly not unimportant to get alignment dialed in damn close to perfect, but it's overemphasized (as is VTA) by vinylphools.

I'd have to rate perfect alignment to some variety of null points no less important than azimuth (or, yaw) or matching gain to cartridge outputs or the detrimental effects of additional rca junctions and IC lengths with signals measured in tenths of millivolts.  These things are infrequently mentioned and have a greater aggregate effect on vinyl playback sonics.

I needed to throw my thoughts in here in case there is a newbie or three tuning in to this post who is now freakin' Code Brown - thinking his set-up is off some how even when he follows his protractor alignment as good as he can.....and it's STILL off

We all diddle with different matters that are important to all of us, and I don't want to spoil you Quants fun in this post....I just wanted to inject a waft of relevancy into the topic (mostly for newbies - as it's hard enough to keep people playing vinyl due to it's inherent complexity, anyhow) 

John

[Wayner]

I agree that there is some plus or minus stuff here, not any magic window. However, good spots make for better record wear, IMHO.

Wayner

[BobM]

I agree that there is some plus or minus stuff here, not any magic window. However, good spots make for better record wear, IMHO.

Wayner

Maybe we should change the thread title to "Finding Your Cartridge's G-spot" 

[Wayner]

Or Gee spot!

 

[bacobits1]

I measured here with a tape, spindle center to tonearm center, 2.75" or more accurately a .222 (2.74") distance. Wayner is correct and so was Basis on drilling it (I would expect them to be).
My settings initially using the Db systems protractor when I did the alignment.
Same setting for a Dennison Soundtractor I used to have. The Dennison only has one null point.
The problem with the Dennison was accuracy on a Rega arm, it is too hard to find exact center pivot point with this device. Perfect for drilling a new arm mount. So, I sold it and got the Db system protractor.
The Guru method of setting anti skate is what I have always used and works quite well.
Listening last night, I'm not moving anything. Reconfirming it lines up to the Guru setting.

Den