Schitt Sol Turntable

[Frank Dernie]

What is needed: a) adjustable dynamic damping; b) pivot at record level; c) pivot matching headshell offset angle; d) dynamic balancing e) gimbal or other fixed bearings with no play f) non contact magnetic anti skating. Have there been tonearms made to those specifications? There must be at least one or two. I mean, is this rocket science? Or are tonearm makers just making it up as they go?

SME V

 

[Thomas_A]

Discwasher company marketed a device called the Disctracker that applied damping (I think pneumatic) to the headshell, riding just in front of the stylus assembly. An outrigger device attached to the headshell screws. It 'rode' the LP providing damping. They advertised it using the Denon DL-103D, as an example of a cartridge that might benefit from its action.

Shure cartridges were viscous damped. Unfortunately, after time in service the damping material (not sure what was used) could dry out, making it useless for the intended purpose. I have a V15xMR with this problem. I know JICO offers replacement styli for the V15, with a brush, but I do not know whether the brush they use is actually damped, or just hinged. My guess is the latter.

The information about Stanton (Pickering) is, unfortunately, the case. The brush rode on a hinge, offset by a 1 gram tracking force increase. It might have provided minimal damping, but that was not its main function. I have one, NOS, and will do a resonance test some time in order to find out if the hinged brush does anything about that.

View attachment 33257

The JICO works fine for the V15 although some of them need a bit of extra damping fluid in the hinges. Not difficult to apply.

 

[AudioSceptic]

A dynamic balanced arm will mitigate against tracking force discrepancy on an unlevel surface.

But if the pivot is appreciably higher than the record itself, there will be increased vertical arm motion (rising and falling) proportional to the distance of the pivot above the record. Again, Dr. Pramanik:

"The height of the horizontal bearing above the record surface is important for reproduction quality. As the tonearm moves up and down under the influence of record warps, the stylus moves in an arc. When the axis of the horizontal bearing is well above the record surface (figure 7a), the stylus will move forward simultaneously with its upward movement, and the speed of the record goove relative to the stylus will decrease. The effect is identical to a decrease in turntable speed, and it lowers the pitch of the reproduced signal. The reverse occurs as the stylus moves down the warp and the pitch returns to nominal value.

The ideal bearing position is at a height above the record surface equal to the height of warps, which results in minimal changes in relative speed (figure 7b)."

View attachment 33431

Sorry, but you describe increased *vertical* motion but the quoted excerpt describes *horizontal* motion, i.e., warp wow.

Also, I'm not sure if the minimum warp wow is when the bearing is at warp height. Shouldn't it be at ½ warp height? And what is typical warp height anyway? I'll have to think about this!

 

[Frank Dernie]

Sorry, but you describe increased *vertical* motion but the quoted excerpt describes *horizontal* motion, i.e., warp wow.

Also, I'm not sure if the minimum warp wow is when the bearing is at warp height. Shouldn't it be at ½ warp height? And what is typical warp height anyway? I'll have to think about this!

However much the warp is the downside is minimised by having the pivot where it should be, at disc level, ie in the same horizontal plane as the stylus.
It should also be perpendicular to the cartridge body.
There are a few properly engineered arms like this but surprisingly few, maybe it doesn't make enough difference or enthusiasts nowadays discard warped records.

 

[AudioSceptic]

SME V

Shame it now costs over £Vk.

This surprised me when it came out because it was so different to all earlier SMEs. They nailed pretty much everything (in a medium mass arm) in one huge jump. The IV uses a spring for bias compensation. Does the V definitely use magnets?

 

[watchnerd]

Shame it now costs over £Vk.

This surprised me when it came out because it was so different to all earlier SMEs. They nailed pretty much everything (in a medium mass arm) in one huge jump. The IV uses a spring for bias compensation. Does the V definitely use magnets?

The SME V might be a near-ideal compromise of design elements for a gimbal type arm...but man $5k for something that is a passive component seems like serious diminishing returns....

 

[AudioSceptic]

The SME V might be a near-ideal compromise of design elements for a gimbal type arm...but man $5k for something that is a passive component seems like serious diminishing returns....

You can spend a lot more on things with obvious bad design elements, such as <https://www.originlive.com/hi-fi/tonearm/>. Scroll down for the whole range but the thing at the top is nearly £10k. And there's the really bonkers stuff out there...

Yes, it's crazy but at least SME make the things, even the other dodgy designs, to exquisite levels of fit and finish. Back in the 60s and 70s they used the term "camera finish", referring to SLRs or quality compacts and range-finders. That might not seem a big deal now, but then cameras were the best examples of precision engineering available to the public at (relatively) sensible prices.

 

[watchnerd]

You can spend a lot more on things with obvious bad design elements, such as <https://www.originlive.com/hi-fi/tonearm/>. Scroll down for the whole range but the thing at the top is nearly £10k. And there's the really bonkers stuff out there...

Sure.

But if one believes in any kind of sense of budget balance in a system, a $5K tonearm (which, granted, will last forever) "should be" paired with a cart that is pricier than I like to spend on components that can be destroyed easily by house cleaners / cats / me after too much drink.

So far, I limit my cart budget to about $1K, as that's what I can tolerate if it goes "poof", a level that would leave me tearful, but not screaming in rage. It would seem a $5K arm would deserve a better cart*.

*this is assuming that carts get better with price, which we all know obviously has diminishing returns and/or is only partially true.

 

[watchnerd]

There are a few properly engineered arms like this but surprisingly few, maybe it doesn't make enough difference or enthusiasts nowadays discard warped records.

I don't keep warped records, trading them in.

Also, most of the records I buy are 180-200g, from plants like RTI, Pallas, which helps a lot in terms of getting good, flat pressings.

I'll also trade in scratched records (including ones I've scratched myself).

 

[Thomas_A]

The SME V might be a near-ideal compromise of design elements for a gimbal type arm...but man $5k for something that is a passive component seems like serious diminishing returns....

I used to have a Linn Akito on my deck but its bearings were going bad. Bought a used Moerch UP-4 with a 4 g armtube. Altough a better match for my Shure V15 (11 Hz resonance) and lower warp-induced noise it is diffiuculr to hear differences. It did track test tracks better though with lower (and audibly so) distortion. The UP-4 need damping fluid and it is thick, 600 000 cst.

 

[watchnerd]

I used to have a Linn Akito on my deck but its bearings were going bad. Bought a used Moerch UP-4 with a 4 g armtube. Altough a better match for my Shure V15 (11 Hz resonance) and lower warp-induced noise it is diffiuculr to hear differences. It did track test tracks better though with lower (and audibly so) distortion. The UP-4 need damping fluid and it is thick, 600 000 cst.

I've always thought the Moerch arms looked great, but I have no idea what they cost nor their features nor have I read a review of one.

They seem very artisanal.

What kind of mount do they use?

 

[Thomas_A]

I've always thought the Moerch arms looked great, but I have no idea what they cost nor their features nor have I read a review of one.

They seem very artisanal.

What kind of mount do they use?

They use a close to Linn mount, just 1 mm difference (exept the 12 inch arms). The DP-8 is special with its asymmetric mass around the pivot which gives very different inertia in horisontal and vertical planes. Korf Blog has some accerelometer measurements of various toneamrs including a Moerch DP-6. Check it up!

 

[Frank Dernie]

The SME V might be a near-ideal compromise of design elements for a gimbal type arm...but man $5k for something that is a passive component seems like serious diminishing returns....

It is expensive but it really is exquisitely made compared to any others I have seen (except my Goldmund T3f which is a bit over the top too). Whether it is worth it for sound maybe not, for knowing you have an arm done properly and if you can afford it, I would say yes.
Particularly when the latest darling of the nutters, which is pretty crap from a proper application of physics pov, is the Swedish SAT CF-1 thing which though generally very nicely made has an arm tube machined so the UD carbon fibres are cut and all the bearings in the wrong place and costs around $30k.
A classic example of nice craftsmanship combined with poor/no understanding of the physics or blind following of the fashion statements like "rigid is better" which is the usual total misunderstanding of dynamic systems from static thinking. grrr

 

[Frank Dernie]

Does the V definitely use magnets?

I don't know. I do think arranging a magnetic system such that the bias force progresses as it should would be a challenge. I wouldn't try it myself.

 

[sergeauckland]

I don't know. I do think arranging a magnetic system such that the bias force progresses as it should would be a challenge. I wouldn't try it myself.

My AEG Telefunken TRS9000 has magnetic bias compensation using a moving iron stub attacked to the arm horizontal pivot, working between two solenoids such that the bias varies across the record. Hugely complicated, yet supposedly theoretically more correct.

All that effort, yet the vertical bearings are not in-line with the headshell offset, nor is the vertical bearing at LP level.

S.

 

[anmpr1]

Sorry, but you describe increased *vertical* motion but the quoted excerpt describes *horizontal* motion, i.e., warp wow.

I follow Dr. Pramanik's syntax. It's a question of a non-intuitive terminology which, I admit, can be confusing at first blush.

In Dr. Pramank's usage, the horizontal bearing is responsible for arm's vertical (up and down) motion. You have to think in opposites for it to make sense. In the diagram, Dr. Pramanik describes the 'horizontal bearing'; not 'horizontal motion'. Instead, he uses the term 'warp and wow' movement, which is a vertical movement. As we know, vertical motion is 'up and down' arm movement which, again using his terminology, is controlled by the 'horizontal bearing'. He calls it that because the bearing is installed parallel or horizontal to the record surface (in a gimbal or knife edge).

Using his terminology, the 'vertical bearings' are responsible for lateral (side to side) horizontal arm motion-- the two bearings on the top and bottom of the arm in a gimbal, placed vertically one on top of the other.

 

[watchnerd]

I don't know. I do think arranging a magnetic system such that the bias force progresses as it should would be a challenge. I wouldn't try it myself.

What's the advantage of magnetics for anti-skate vs other means?

 

[anmpr1]

The JICO works fine for the V15 although some of them need a bit of extra damping fluid in the hinges. Not difficult to apply.

Do you apply silicone at the brush hinges? What instrument do you use to get the thick gunk in the small hinge?

 

[anmpr1]

What's the advantage of magnetics for anti-skate vs other means?

I would think (and it's only a guess) that being non-contact there would be less mechanical interaction with the arm--mechanical friction/resistance and resonance. Whether it would have any sonic influence I can't say. It is simply (to my mind) a more elegant solution to the problem. And you wouldn't have to worry about losing the weight, or breaking the little string that goes with the weight.

 

[watchnerd]

I would think (and it's only a guess) that being non-contact there would be less mechanical interaction with the arm--mechanical friction/resistance and resonance. Whether it would have any sonic influence I can't say. It is simply (to my mind) a more elegant solution to the problem. And you wouldn't have to worry about losing the weight, or breaking the little string that goes with the weight.

But springs don't get lost, either.

And while magnetic strength follows the inverse law, I'm not sure how well that maps to the change in skate force across a record.