Shure stylus microscope

[dshoaf]

C_dk, my experience with the Shure system was that it was far less detailed than the Mac system for sure! Frankly, most folks in our buying town (a small university located close by) were less concerned about the technical aspects than the typical Mac buyer - yes, I'm generalizing a bit.

I did find, however, that Sparky's observations that the cantilevers in cartridges were not necessarily in perfect alignment with the cartridge bodies. Yes, it would contribute to uneven wear of the stylus but it also would be borne out during testing.

The Shure C-PEK test device used phasing to determine the best crosstalk adjustments of the cartridge mounted to the turntable under test. That is, I would mount the cartridge (didn't make any difference if it was a Shure) into the customer's turntable and then adjust vertically and horizontally for the best tracking at the cartridge spec and the widest crosstalk spec I could achieve.

What I found was that the arm/headshell/cartridge/stylus/cantilever assemblies all interacted and that finding that sweet spot took some time and effort with the C-PEK.

BTW, I also discovered that there wasn't anything magical about the crosstalk testing with the Shure C-PEK. It was just a metered readout of the phase relationship between the 2 channels of the cartridge when using a single tone band of the Shure Test LP. I could duplicate the same measurement using a Lissajous patter on a scope with the X and Y axis being the inputs.

Since the whole emphasis from Shure was to sell more cartridges, I can understand why their approach to doing measurements in the field without _lots_ of training from the Shure factory was used. I can also see that Mac's approach had far better accuracy but, based on my experiences in a mid-level, small-town audio shop, Shure catered to the masses and Mac catered to keeping its customer very happy and maintaining their reputation for the complete audio experience. I applaud both.

BTW, it was great to see the old ad, C_dk! I may still have a picture of me standing behind the counter at the shop I worked in but haven't seen it of late. My experiences date from 1973/4 to about 1978, Sparky. I went off into the budding computer biz after that for about 30 years.

Cheers,

David

 

[c_dk]

Well I still have my Wild but along with other stuff is buried in my audio closet. The diamond chips used in most bonded styli could be 3 to 4 degrees off most nudes were within 2 degrees. We would cull them to less than 2 and 1 respectively. Drove our reps crazy but so what.

An elipse by definition has sections of 120 (2) and 60 (2). If you rotate the stylus tip to look at the contact surface beyond +- 20 degrees you will see a light pattern and the idea was to adjust down the lamps to just see the reflection of the non worn surface. When roatating the non worn stylus through the collumated light sorces the reflected patterns would stay the same. As the stylus was worn you could see a change in the pattern because the radias of the worn surface was different than the radius of the non worn surface. The rotating table with degree marks was the key to being able to measure the amount of wear.

With practice you could measure each quadrant; think of the insight then available as to how the arm was set up.

This was from an American amp and speaker company, when Gordon Gow would come to my shop he would always spend at least 15 minutes talking about TT setup. One of the great times I had with him was setting up the 3rd out of 5 Mac moving coil prototypes.

 

[Grainger49]

I used these when new. They work well. But for THAT price you can get a real microscope, add a couple of lights at the sides and buy some LPs.

 

[c_dk]

C_dk, my experience with the Shure system was that it was far less detailed than the Mac system for sure! Frankly, most folks in our buying town (a small university located close by) were less concerned about the technical aspects than the typical Mac buyer - yes, I'm generalizing a bit.

I did find, however, that Sparky's observations that the cantilevers in cartridges were not necessarily in perfect alignment with the cartridge bodies. Yes, it would contribute to uneven wear of the stylus but it also would be borne out during testing.

The Shure C-PEK test device used phasing to determine the best crosstalk adjustments of the cartridge mounted to the turntable under test. That is, I would mount the cartridge (didn't make any difference if it was a Shure) into the customer's turntable and then adjust vertically and horizontally for the best tracking at the cartridge spec and the widest crosstalk spec I could achieve.

What I found was that the arm/headshell/cartridge/stylus/cantilever assemblies all interacted and that finding that sweet spot took some time and effort with the C-PEK.

BTW, I also discovered that there wasn't anything magical about the crosstalk testing with the Shure C-PEK. It was just a metered readout of the phase relationship between the 2 channels of the cartridge when using a single tone band of the Shure Test LP. I could duplicate the same measurement using a Lissajous patter on a scope with the X and Y axis being the inputs.

Since the whole emphasis from Shure was to sell more cartridges, I can understand why their approach to doing measurements in the field without _lots_ of training from the Shure factory was used. I can also see that Mac's approach had far better accuracy but, based on my experiences in a mid-level, small-town audio shop, Shure catered to the masses and Mac catered to keeping its customer very happy and maintaining their reputation for the complete audio experience. I applaud both.

BTW, it was great to see the old ad, C_dk! I may still have a picture of me standing behind the counter at the shop I worked in but haven't seen it of late. My experiences date from 1973/4 to about 1978, Sparky. I went off into the budding computer biz after that for about 30 years.

Cheers,

David

Being a Mac store and with Mac speakers that would go deep always had to deal with feedback and record warp exciting the arm/cantilever suspension system.

AT/Signet also used a cpec and imported Wild scopes for non Mac dealers. I believe they also started bringing in Nikon scopes when the Swiss franc/dollar exchange exploded the Wild price. The Nikon did not have a turntable which again limited it's use.

I found dialing in the crosstalk really expanded the soundstage and perceived image and detail