Schroder lT installed, pics a few comments...

hvbias

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Jun 22, 2012
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This looks like a very cool tonearm. Would it be possible to see a video of it in action?

What is the armwand mass, I take it the Atlas likes a fairly beefy armwand?
 

jfrech

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This looks like a very cool tonearm. Would it be possible to see a video of it in action?

What is the armwand mass, I take it the Atlas likes a fairly beefy armwand?

How about this...tomorrow I'll set my camera up on a tripod...take a few pics 30 seconds apart...this might show the back of the arm moving better.. a video you'd really have to speed it up....
 

hvbias

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Jun 22, 2012
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How about this...tomorrow I'll set my camera up on a tripod...take a few pics 30 seconds apart...this might show the back of the arm moving better.. a video you'd really have to speed it up....

Whatever is easiest for you. Youtube videos can be sped up once you download them with a Firefox/Chrome plugin.

Thanks Sean.
 

jfrech

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audioarcher

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No problem. I saw it on the Schröder LT thread on Audiogon and thought WBF members would like to see it too.
 
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hvbias

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ack

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That's just a marvel of mechanical engineering, very impressive; and the sound in the video appears to be so good.
 

PeterA

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Thanks for the pictures John. There is a thread over on Audiogon explaining some of this. A poster named Hiho explained how it remains always tangent. I will try to paraphrase what he wrote. He basically explained that the straight line drawn from the stylus down the arm tube and the straight line from the stylus to the spindle form an angle of 90 degrees. That is why there is no overhang. As long as this angle is always 90, regardless of where the stylus is on the lp, it will be tangent or perpendicular to the groove it is playing. In other words, the stylus always finds a tangent or null point continuously as it plays. So instead of being perpendicular to two radii during play like a normally pivoting arm, this arm is continuously perpendicular to one radius of the lp at all times, so it is always tangent because that angle is always 90 degrees. The arm base moves along this guide allowing the stylus to always be perpendicular to a radius line. It does not have two null points, it has an infinite number, or at least as many as can be calculated during the course of the side of an LP.

At least that is how I understand it. Very interesting geometry problem. The bearings must be extremely good for this mechanism not to chatter sending vibrations up the arm to the cartridge as the arm base moves along that arc.
 

jfrech

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That's just a marvel of mechanical engineering, very impressive; and the sound in the video appears to be so good.

You know, when I first picked up the LT arm from the flight case, glanced at it for a few min....that was exactly my response. Just impressive engineering. Very simple approach really. one bearing for vertical, 2 for horizontal and a guide in a race track with another bearing a powerful magnet. Then the obsessive precision in bearings, wiring and perfect assembly. It's one of those things when you see and feel it...you know why it's costs what it does....and when you hear it...you forget what it cost. Steve was telling me about the wiring...it's not just off the shelf...and a extreme amount of time goes into it as well...just how he spends a hour or two unwinding the silk (maybe it was cotton) insulation to prep for the connections...

Given what we all spend on our systems...it's a total bargain. I know I might have buyers bias...all I can say is hear the before and after...
 

ack

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The constant right angle is not what impressed me (that's what you would expect from a linear tracking arm) - *how* he maintains constant (and zero) overhang *all the time* (which will give you the right angle) is what's so special about this design, and I would like to understand how he manages the skating force to achieve that end goal; that lateral-force management is what's really impressive, to be able to convert part of it and move the arm forward, and we are not talking about some insignificant amount of mass that has to move here... it's all really in the geometry...
 
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MylesBAstor

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Apr 20, 2010
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The constant right angle is not what impressed me (that's what you would expect from a linear tracking arm) - *how* he maintains constant (and zero) overhang *all the time* (which will give you the right angle) is what's so special about this design, and I would like to understand how he manages the skating force to achieve that end goal; that lateral-force management is what's really impressive, to be able to convert part of it and move the arm forward, and we are not talking about some insignificant amount of mass that has to move here... it's all really in the geometry...

I thought it was done magnetically.
 

TBone

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Neat, but curious arm ...

It does have a guide bar that allows the 2nd pivot to slide sideways (vs a pivot). it's a bearing in racetrack...with magnets that keep the bearing from touch the track during playback. When you're cueing the arm for play...you can feel when the movement exceeds the limits and the bearing hits the side of the race track.

So ... when it hits the side of the tracks, the magnet pulls it back to center?

How does AS work, is it also magnetic?
 

ack

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You know, when I first picked up the LT arm from the flight case, glanced at it for a few min....that was exactly my response. Just impressive engineering. Very simple approach really. one bearing for vertical, 2 for horizontal and a guide in a race track with another bearing a powerful magnet. Then the obsessive precision in bearings, wiring and perfect assembly. It's one of those things when you see and feel it...you know why it's costs what it does....and when you hear it...you forget what it cost. Steve was telling me about the wiring...it's not just off the shelf...and a extreme amount of time goes into it as well...just how he spends a hour or two unwinding the silk (maybe it was cotton) insulation to prep for the connections...

Given what we all spend on our systems...it's a total bargain. I know I might have buyers bias...all I can say is hear the before and after...

Thanks, I am eager to read his patent when granted. I think everyone sees the engineering effort and ingenuity behind this arm and no one is discussing cost, unlike say that Venere (?!?) Tenere (?!?) arm?
 

jfrech

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Neat, but curious arm ...



So ... when it hits the side of the tracks, the magnet pulls it back to center?

How does AS work, is it also magnetic?

Actually it only seems to hit the side when you physically handle the arm...the magnets are powerful enough that during needle in the groove playing time, the magnets do all the work...very stable with warps etc etc...

I don't think this arm needs antiskating. apparently very little side force is exerted on the cantilever, this is one the key elements to this arm sounding so good...as to why, I can't really comment...would be a great question for Frank Shroder or Steve Dobbins...
 

TBone

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I'm in the market for another arm, but not to replace the arm I currently use. It needs to be high quality/unique; such as the Audio Origami PU7 or perhaps RP1 http://odysseytonearms.blogspot.ca/, and this particular Shroeder is truly unique ...

Actually it only seems to hit the side when you physically handle the arm

So ... is handling the arm then a more delicate process?

Does the magnet "damp" in any way?

I don't think this arm needs antiskating.

Probably not, I should've figured that ...

would be a great question for Frank Shroder or Steve Dobbins

So many questions loom, of which I'm assume he's already been asked. I'm especially interested on how it maintains 90 degrees, hopefully it's not one of those 'it has to be off before it's on' arrangements?

Anyway, very interesting indeed ...

tb1
 

jfrech

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I'm in the market for another arm, but not to replace the arm I currently use. It needs to be high quality/unique; such as the Audio Origami PU7 or perhaps RP1 http://odysseytonearms.blogspot.ca/, and this particular Shroeder is truly unique ...



So ... is handling the arm then a more delicate process?

Not really more delicate ...just different...I'm used to a pivot to swing back...this is more of a slide...after a few times doing it...you know how it moves and really don't hit the race track stops...you just slide it back. It feels VERY solid and VERY precise with in it's operating range...
 
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TBone

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Nov 15, 2012
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Thank you very much for your post / replies ... perhaps when more details emerge, you can post 'em ...
 

berlinta

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Dec 4, 2013
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Hello gentlemen,
I think I may be able to shed some light on a few issues discussed in this thread.
First of all, a US patent for the mechanism that is the heart of this tonearm has been granted on Nov. 5th. In addition, it is protected under design copyright law in the EU.

The use of this arm on any softly suspended deck(like a Linn LP12, Oracle Delphi, Voyd....) is less than optimal. Just like any tonearm - and airbearing tonearms in particular - the arm needs to be levelled(a provision for which is "hidden" in the arm base) or else the advantage of no side thrust generation(lack of skating force) will be jeopardized as, similar the an air bearing "sled", the pivoted arm will find a gravitational "null" or resting position. It's not as pronounced an issue as with airbearing arms as the mass displacement is a lot smaller, but still...

Tangency is maintained through a vector addition. Lateral tonearm displacement (and frictional pull) will move the fixed outrigger underneath the main arm bearing to which a magnet is attached. That magnet always maintains minimum proximity to the ferromagnetic "guide-rail" above, yet never touches it. So for any given angle that the main tonearm assumes, the pivoting bar is forced to move so that the magnet stays as close to the bar as possible.
Yes, that mechanism needs excellent, in fact, the very best bearings one can buy. The total bearing friction in the lateral plane(<3,5mN) is lower than ANY other conventional tonearm with captive bearings. In the vertical bearings, friction is ZERO, as in unmeasurable/waaay below what the wiring is contributing.
The slightest whiff will move the arm across a blank record, and a hair, gently put on the headshell while the arm is in equilibrum, will displace it. Yet there is NO play in any of the bearings in operation.

No skating compensation is required, even if set up with a little less care than what one should apply, side thrust on the cantilever can be brought down to unprescedented low levels. This means that it now takes the same amount of force to displace the cantilever laterally in either direction from center(all bass below 80-100Hz is mono on LPs), increasing linearity/dynamics/extension.

The eff. length was not chosen arbitrarily, but yields the best combination of geometry and associated forces. Longer wouldn't result in less tracing error(so why do it?), shorter forces the displacement of the pivoting bar to increase, requiring more force.

Sorry if this reads like an advertizing pamphlet, it isn't supposed to be one...

And I'm really happy that, so far, people who spent their hard earned money on this, really seem to "get" it! :)

Forgive me for stopping short of revealing everything that contributes to the fidelity of this arm, as I like to reduce the risk of plagiarism to a manageable level :)

Happy listening!

Frank Schröder
 
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