Shure v Pickering Resonance

[anmpr1]

This is a spin off from the Schiitt turntable thread, which I didn't want to pollute with more off topic stuff. We were discussing the use and abuse of the Shure/Stanton brushes as they relate to controlling arm-cartridge resonance. Since I have a new M97xE and a NOS Pickering XV-15 1200e (equivalent to the Stanton 681eee) I thought I'd compare them. Shure uses a viscous damped brush as part of the stylus assembly (first seen on the V15 IV, I believe), while Stanton uses a simpler hinged brush affixed to the stylus assembly. The Stanton/Pickering invention was earlier than the Shure, and advertised as a 'Dustmatic' brush. Shure was advertised as a way to control arm-cartridge resonance, which Shure claimed ought to be at 10Hz, or higher.

To demonstrate their new cartridge, Shure came out with the TT-117 test record. I obtained one by purchasing a first gen V-15 MR cartridge. As I recall, there was a coupon you could send in, and Shure would send you the record for free, or maybe a few dollars. I don't recall details. It's a simple 'look, see, and hear' test. You play the bands and watch the cartridge as it tracks the levels, listening for test tone changes. Nothing fancy like measuring anything on a scope.

I used the Garrard Z-100 arm, because it highlights problems. The arm is underdamped and consists of numerous articulating pivots. A good arm to test with.

With the Shure damped brush it was difficult to observe any arm movement, and difficult to observe resonance at all. The arm was very controlled. I did not test the Shure without the brush. I should do that. The Pickering exhibited marked resonance between 7-8 Hz, with arm oscillation and some warbling of the tones. The brush made no difference at all. If anything, it might have made things a bit worse.

Conclusions: IMO the Moving Iron Pickering 'sounds' better than the Moving Magnet Shure, strictly from a sonic standpoint. I can't really say why. Maybe I just like the fact that it's an almost 50 year old cartridge, and I'm reliving my past. However that is, in the Z-100 arm the Shure is definitely a better cartridge to use. In any case, both are history. Below are some pics. For anyone interested, the Garrard is still as cluncky and Micky Mouse as it was 50 years ago. But it runs as new. I love it for all that.

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[restorer-john]

Boy, that M97xe looks like you dug it out of the dirt. It's really crusty and hardly "new".

I guess you mean "new" as in newer than the 50 year XV15...

 

[anmpr1]

Boy, that M97xe looks like you dug it out of the dirt. It's really crusty and hardly "new".

I guess you mean "new" as in newer than the 50 year XV15...

Anything I bought in the last two years or so I still consider new. But you are right, it's actually old and deader than a door-nail, at least as far as Shure is concerned. Some opportunists on eebay are selling NOS 97s for $250.00. OK. Just remember that it's a one hundred dollar cartridge, for crying out loud.

On the other hand, the fact that it does certain things so well at that price point shows you how 'overpriced' a lot of cartridges are. In the land of phono, once you get past a certain dollar amount, it's mostly nonsense. But I guess that's true for anything audio related.

 

[pozz]

Doesn't tweaky stuff like those brushes usually backfire? The added friction is sure to mess something up, no?

General noobish question about arm resonance: the story goes that the Technics SL-1000R arm is made from of a custom alloy with better resonance characteristics than the aluminium arm of the SL-1200—how seriously should I take that claim?

 

[anmpr1]

Doesn't tweaky stuff like those brushes usually backfire? The added friction is sure to mess something up, no?

General question about arm resonance: the story goes that the Technics SL-1000R arm is made from of a custom alloy with better resonance characteristics than the aluminium arm of the SL-1200—how seriously should I take that claim?

A) the Shure brush adds 0.5g to the tracking force, It is damped and helps control arm resonance, dealing with small warps very well. I have not experienced any audible negative effects using it. Because of it's beneficial effect, I would not say that is a 'tweaky' invention. However, it hinges up andout of the way, so if it's a problem for anyone, they can remove it from the chain.

B) I imagine that any change in arm tube composition is going to affect resonance and vibrations, at least to some degree. Whether the result is positive or negative, or has no effect at all, I can't say. I think some changes are just that. Changes.

As far as the latest and greatest Technics arm? For the price they are charging I think it is appropriate to ask whether their new arm is an advance over their erstwhile EPA 100 versions, or the EPA 500 system? My guess is that the answer is, 'no'. But I don't have one, so it's only a guess.

 

[pozz]

Because of its beneficial effect, I would not say that is a 'tweaky' invention.

Isn't that what they all say

I'm out of my depth here, honestly. If the resonance is sub-20Hz as you said in the other thread won't a rumble filter remove it anyway?

 

[anmpr1]

Isn't that what they all say

I'm out of my depth here, honestly. If the resonance is sub-20Hz as you said in the other thread won't a rumble filter remove it anyway?

A subsonic filter is helpful for filtering out LF garbage generated by the turntable system, and sent to the amplfier. During the days when phono was king, most preamps had them. A filter will not, however, affect arm/cartridge resonance since what is being addressed in this instance is the ability (and stability) of the arm/cart to navigate warps, aleviating mistracking and the accompanying distortion.

I want to clarify what I wrote about the Shure: you add 0.5g to the downward force, but the brush 'absorbs' that. So if you want to track at 1.5g, you set the arm dial to 2.0.

In a way it is the same principle as a shock absorber on your car. The best place to locate the shock absorber is at the tire. I suppose it could be mechanically applied far away from the tire/wheel, but what would be the point? Same with the tonearm/cartridge. That said, I've used the Shure system in combo with pivot damping, and found no real problems with that.

Back in the day many arms were designed with some sort of damping. In the 1950s, the Gray arm used oil damping at the pivot. Here are three pages of the Japanese version, explaining how it works:

http://www10.big.or.jp/~dh/codo/arm/arm.html

A popular non-oil damped arm was the Dual system, which used a 'floating' subweight inside the main counterweight. The idea was to break up the main resonant mode into smaller, easier to handle, modes. It was used on the 701, 704, 741 and a few others. The Technics EPA 100 arm used a combination of magnetic and oil damping in the counterweight to provide damping past the pivot. The EPA 500 system used this, along with different arm tubes that matched cartridge compliance. Heavier tubes were used for low compliant carts, and lighter tubes for higher compliant ones. If Panasonic is not using it anymore, I presume it is because they don't care about it. At the price they are charging, you'd think they'd be able to fit it in. But I guess not.

Other damping schemes included the Sony/Denon/JVC electromechanical pivot damping mechanisms. There were some exotics like the '60s Castagna arm which used dual opposed magnets to provide a degree of damping (Sao Win used this arm for his SDC/SEC turntables). One manufacturer (I forget the name) used a trough (filled with silicone gunk) mechanism at the cartridge end of the tonearm. It fitted over the record, providing damping. Keith Monk used a mercury bath in his pivots (this was before the EPA, I guess). I'm sure there are other schemes.

Most of this is forgotten in the low to mid priced turntable range. The Shure was an easy and cheap way to achieve results. But now that is gone. If you own an SL-1200 the KAB device works well, and is not too expensive. Otherwise, if it is important to you, you have to spend beaucoup dollars for a dedicated arm with damping. SME used to make them--maybe they still do. I don't follow the tonearm scene much, anymore. All my interest is mostly historical.

PS: Frank Dernie on this forum spent a lifetime studying this stuff. He's probably forgotten more than I'll ever know about this subject. Check out some of his posts on the subject. We can learn from him.

 

[pozz]

@Frank Dernie Would you mind offering your perspective?