Shure Test Record Questions

[wanders]

I have a Pioneer PL-570 with two cartridge/stylus set-ups: an AT Compass/ATX5E (1.35g); and an AT-455ex/ATN-12S (1.25g). Both of these cartridges are old; both styli/styluses are new in the last six months.

I just acquired the Shure Obstacle Course IV test record. The Compass seemed to handle everything reasonably well. The 455ex showed some break-up on the flute (mid-range) test at levels 4 and 5. In my understanding, the AT455ex would have been the superior cartridge.

A couple of questions: Is my estimate of the AT455ex incorrect? Are my tracking forces about right? Would differences of, say, 1.25g to 1.35g be significant here? I use the 49mm alignment method being careful to ensure that both mounting screws are the same distance from the front of the headshell. Should I be looking at more precise alignment methods? Wonder if I should be thinking about a better cartridge setup?

Finally, according to the test record, my speaker alignment is backwards. Sitting in front of the speaker, the sound from the “supposed” left speaker comes from my right, and vice versa. All amp, preamp, speaker connections are correct; amp power indicators are in agreement. Comparing a cd to the same vinyl record, the orientation is identical. Could the test record be looking from behind the speakers?

Thanks for any thoughts.

 

[beatcomber]

I use the 49mm alignment method being careful to ensure that both mounting screws are the same distance from the front of the headshell. Should I be looking at more precise alignment methods?

The mounting screws has nothing to do with the alignment. You have to measure from the stylus tip to the ring on the headshell collar.

Finally, according to the test record, my speaker alignment is backwards. Sitting in front of the speaker, the sound from the “supposed” left speaker comes from my right, and vice versa. All amp, preamp, speaker connections are correct; amp power indicators are in agreement. Comparing a cd to the same vinyl record, the orientation is identical. Could the test record be looking from behind the speakers?

Maybe your speakers are incorrectly positioned?

 

[wanders]

The mounting screws has nothing to do with the alignment. You have to measure from the stylus tip to the ring on the headshell collar.

Maybe your speakers are incorrectly positioned?

I measure the 49mm, as shown, then ensure that both mounting screws are exactly the same distance behind the front of the headshell. You could get the stylus at 49mm and have still have the mounting screws cockeyed.

 

[Doug G.]

1.25 grams is too light for an ATN12S stylus. That is a Shibata stylus and requires more like 2 grams VTF.

It won't hurt anything because that force with a shibata is about the same, as far as record and stylus wear, as an elliptical or conical tracking at 1.25 grams.

Check to make sure your cartridges are wired correctly for the channel reversal problem.

White = Left positive
Red = Right positive
Blue = Left negative
Green = Right negative

Doug

 

[Doug G.]

Oh yes, and instead of going by the mounting screws, ensure that the cartridge body is square in the shell. Not turned one way or another.

Doug

 

[wanders]

1.25 grams is too light for an ATN12S stylus. That is a Shibata stylus and requires more like 2 grams VTF.

It won't hurt anything because that force with a shibata is about the same, as far as record and stylus wear, as an elliptical or conical tracking at 1.25 grams.

Check to make sure your cartridges are wired correctly for the channel reversal problem.

Doug

Great advice on the shibata; I'll increase the vtf.

As to the speaker alignment, I recently veneered the tt and, in the process, removed and replaced the tonearm wiring connections (not the tonearm wires). At the same time I replaced the factory patch cords with low capacitance cables. Knowing little about electronics, I was scrupulously careful about putting everything back in the same place. Both cart/headshells behave the same. And, I have one vinyl record/cd duplication (S/G Bookends) which has lots of stereo effect. The tt and cd outputs are the same orientation. But your broader point is probably right: Something is screwed up (it's always pilot error).

 

[wanders]

Oh yes, and instead of going by the mounting screws, ensure that the cartridge body is square in the shell. Not turned one way or another.

Doug

Yeah, but when the cart and stylus look square, there is still a little wiggle room with the screw positions where it still looks right. Maybe overkill.