Shure SFG-2 - Safe to use with LOMC carts?


I am reading mixed reviews on this. Some say its not accurate to to the magnets and some say that it might even destroy the cart.
crazyravr
From Shure Pro Audio website....

Question
Can the SFG-2 be used with moving coil cartridges, or only with moving magnet cartridges? It is my understanding that the magnets in moving coil cartridges are powerful enough to attract the stainless steel balance beam of the SFG-2 and produce incorrect readings.

Answer
Can the SFG-2 be used with moving coil cartridges, or only with moving magnet cartridges?
* We only speak for Shure cartridges - all are moving magnet and work well with the SFG-2.

It is my understanding that the magnets in moving coil cartridges are powerful enough to attract the stainless steel balance beam of the SFG-2 and produce incorrect readings.
* This is feasible, though we have never tested the theory. Most phono cartridges use Mumetal for the cartridge body; MuMetal acts as a magnetic shield, thus shielding the internal mechanism from outside magnetic influence and vice versa.

* FYI - Stainless steel has no, or very slight, magnetic properties.
My experience with the Shure gauge (vintage 2006) and a LOMC cartridge lead me to the conclusion that I won't put a Shure gauge anywhere near my cartridges anymore. The supposedly non/low-ferrous stainless platform had enough magnetic attraction to pull the cartridge down and collapse the cantilever. Luckily the cartridge body has an inset that prevented the cantilever from collapsing completely so the cartridge is OK and still plays fine. I now use a digital gauge.

Tom
I'm having a deja vu moment...

Is that you, Tom?

Tom
I have an older SFG-2, at least 20 years, and have never had any problem during that time with MC cartridges, regardless of output.
Thanks for the interesting quotes from Shure. Companies post what they think will sell product, but this is worse nonsense than usual.

Most phono cartridges use Mumetal for the cartridge body; MuMetal acts as a magnetic shield, thus shielding the internal mechanism from outside magnetic influence and vice versa.
Shure conceded they have no experience with MC's, so this self-serving statement is pure speculation. It's also untrue. Like many A'goners I've used dozens of LOMC cartridges from multiple manufacturers. Their magnetic fields all extend well beyond the cartridge body.

* FYI - Stainless steel has no, or very slight, magnetic properties.
Self-serving, generic and metallurgically inaccurate. Most non-austenitic SS alloys are attracted to magnets. The strength of the attraction varies with ferritic content and the polar orientation of the molecules within the object.

Multiple owners report that some (but not all) SFG-2's are attracted to magnets (mine isn't). This inconsistency could be explained by inadequate materials sourcing specifications at Shure, which would be consistent with Shure's assumption above. If Shure neglected to specify austenitic SS then some magnetically attractive gauges could have resulted. Non-austenitic SS alloys are generally less costly, so that's what Purchasing or a supplier would choose unless Engineering specified otherwise.

It's easy enough to check yours of course. Just put a magnet near it. :-)

If it is magnetic, the risks of using with a LOMC are twofold:
(i) magnetic attraction between cartridge and balance would invalidate the accuracy of the measurement;
(ii) magnetic attraction might yank the gauge into the cantilever and damage it (unlikely, not impossible).

If you have a $500 (or $5,000) cartridge, why skimp on a VTF scale?. Good electronic ones can be had for $60 or even less. Search here or on ebay.
Dear Crazyravr: The inconsistency that is almost the " rule " with Shure in this subject makes that you can't have a precise answer.

As like Pryso my Shure gauge works just great but this could mean almost nothing because that Shure build material quality inconsistency.

As Doug point out maybe is better other gauge choice.

Regards and enjoy the music,
Raul.
Just for statistics, my gauge (vintage 2007) was magnetic. Please avoid the risk!
I used SFG-2 with my Denon DL 160 (HOMC) to set the tracking force to 1.8g, but when the checked the weight again with a Digital guage, it indicated the actual tracking weight @ 2.1g. Avoid SFG-2 with MC
The older SFG-2 models used a steel balance beam with ferrous content and would attract to a magnet. At some point later in the production history this part material was changed to a non-ferrous metal which is not attracted to a magnet. (looks like stainless steel)

I have one that I purchased in the late seventies. It has the non-ferrous balance beam. Therefore, safe with MC or any cartridge with a strong magnet.

I also use an electronic vtf scale. A so-called "Micro-Tech" that was sold by Express Machining. In practice both the Shure and the Micro-Tech produce identical readings. And the Shure was far cheaper. But the Micro-Tech is more convenient and quick to use. No balance beam slider to fiddle with, just place the stylus on the little shelf thing and read the reading.

I still like the Shure, however.

-Steve
My SFG-2 was 0.6g off. If I set it to 2.0g on the Shure, it was actually 2.6g. I gave it to the trash can. I'd say stay away from this gauge.
I think the variation in responses suggests inconsistencies within Shure's mfg process.
It seems later examples are responsible for the negative responses in this thread. Perhaps these later examples of the gage have been manufactured out of the country. Perhaps Mexico?

That is not to say that good product can't be produced anywhere around the world, including Mexico. It does suggest the possibility that Shure no longer assures the quality of this product the way it once did.

All that said, the older example that I have is not attracted to a magnet and reports vtf accurately.

It's a shame about these other examples. I'll make sure not to recommend the gage any more.

-Steve