Hi, Babybear and myself recently purchased these arms and installed in our systems. We both posted comments on our system page threads...in a nutshell, it's a amazing sounding arm...
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Lewm, That sounds logical. It's not quite the same as being a little off on overhang with a normal pivoted arm. On a LT arm if you are a little off it will be off the same amount all the way across the record unlike a normal pivoting arm. The cartridge can be adjusted back and forth in the headshell on the Schroeder LT to make up for any error with pivot to spindle distance. As long as the P2S distance is not so far off that you run out of adjustability at the headshell you will be ok. |
lewm, I think sarcher30 hits it about right. All I know is this arm makes some seriously beautiful music...I feel like I have a whole new vinyl front end...not just a arm... it's pretty impressive...honestly I was a ways down the road on a very pricey phono stage...thinking that was my next step...now I no longer feel I need to upgrade my phono...so in this context...it's actually the lower and better priced alternative. I have some pics on my system page for those interested... |
Hi, Here is a youtube video link from this past RMAF that "might" give you a better feel for how the Schroeder LT arm operates. http://www.youtube.com/watch?v=QYqcQl5pLgU I also have the arm installed on my Beat TT and I would echo what John has said about the sonic performance of the arm. I've tried to describe as best I could what I hear with the LT arm on my system page. Hope that helps a little. Arnie |
The first video is fascinating. The second one does not really give a sense of what is happening. I would think that for it to have truly linear (tangental) movement, the stylus must follow a straight line moving along the exact radius of the LP, theoretically ending at the spindle or center. It looks like this is accomplished by the base moving in and out and being hinged at two points and moving along an arch. But I don't see that the base moves the entire 5" or so that represent all of the grooves on the LP. It's a very intriguing design and a difficult geometry problem to visualize. The bearings must be extremely silent and free of slop for there not to be any chatter considering all of the movement at the base where it can vibrate. Could Arnie or jfrech add some clarification? |
Just think of the stylus to the armwand as a straight line and the stylus to the spindle another straight line and the two lines form an angle and as long as that angle always maintains 90° then it doesn't matter what the base is doing or whether the arm goes in an arc or not. And it will track tangentially. The same theory applies to the Thales tonearm, except it pivots at the headshell, whereas the Schroder has a fixed one with no offset angle. The Schroder does not use the Thales geometry but having an understanding of the Thales semi-circle will give you a better idea. The advantage of the Schroder and Thales tonearms is that they do not have to use linear bearings with its enormous horizontal mass. The Schroder also has advantage over the Thales of having little to almost no skating force, hence the absence of anti-skating adjustment. Ingenious indeed! Thales semi-circle _______ |
Hiho, Thanks for the explanation. It is much clearer now. As long as that angle is 90 degrees, the stylus does not need to trace the radius of the LP. It is constantly hitting a different radius as the LP rotates which is why it is always tangent while a normal pivoting arm only hits two radii, (at the null points) during the entire side. That is why the arm base does not have to move that 5" or so. This arm is constantly adjusting. |
The first video is a very good demonstration of the mechanism of the Schroeder. I had not previously realized that it's pivot swings in full view. I thought the working bearings were underneath, somehow. Fascinating and ingenious, because it's so obvious and simple. Could not help notice the Abolare linestage, using two 12AU7s, my least favorite audio tube, and for only $32,500!!! I have never heard a 12AU7 I could love, and no linestage imaginable should cost that much. Sheesh. But I do like Rockport speakers and The Beat turntable. |
Hi Peter no chatter and zero vibration, you can "hear" this in the stellar resolution this arm has. Other arms I had to remove damping troughs, fine vtf weights, anti skate mechanisms even finger lift b/c they chattered, rattled or colored the sound. The magnets keep the bearing in the underneath race centered in the race so they never touch unless your physically moving the arm by hand to its rest position. Hope this explanation helps |
Yes, I want one. I wonder whether Frank Schroeder can create a base that would allow other tonearms to operate in the same manner. The problem would be that nearly every commercial tonearm has an offset headshell. The only production arm I know about that does not have an offset headshell is one of those Nottinghams. There are also a few with adjustable headshell offset angle. Still, if he could produce a base for $1500 or less, he would sell quite a few of them. |
Sorry to be such a blabbermouth on this subject. I saw a full photo of the LT on the Xactaudio website. It seems I was correct in the first place; there is a large cylindrical base, not seen in the videos, within which must reside the bearing for pivoting the pivot point. I hope that would not delimit the use of the tonearm on a wide variety of turntables (e.g., my SP10 Mk3 or my L07D). Probably it would not fit on the L07D, at first glance. |
Lewm, The spindle to the center of the mounting hole distance (1 inch hole for the post) is 277 mm. I have made a new arm board for my SP10 mk2a plinth to accommodate the Schroeder LT. I am expecting the LT in a month or two. You should have no problem mounting one on the MK3 as long as you can accommodate a normal 10.5" arm. I did have to drill a hole all the way through the whole plinth as the tonearm cable exits the bottom of the post. The difficulty will be mounting it to TT's that can only accommodate 9" arms. They may want to eventually design a shorter version for those TT's. |
Thank you, Frank. Unfortunately for my bank account, you've removed one reason for not buying an LT. Congratulations to you for the inherent rightness and simplicity of your idea. You might suggest to Xactaudio that they should explain the presence of that cylinder supporting your tonearm in the photos. (Maybe they did; sometimes I am a sloppy reader.) |
More close up picture and pictures from patent. Hope they help clarifying the concept. Picture 9 Picture 10 Picture 11 _______ |
I am still looking for a picture that shows the bottom of the plate that covers the magnetic guiding mechanism. Understandably it would require, if possible, an awkward low camera angle or having the tonearm upside down. The patent drawings spell out the obvious, but I still would like to see an actual image. _______ |
I am wondering how the effective mass can be so low as "14 to 21 gm", which was stated somewhere above. If you think of it, the stylus/cantilever is swinging the whole enchilada all the way back to the stationary pivot that bears the rotating pivot apparatus. Thus the effective mass would be the additive of the masses of the swing arm, the base and pivot assembly at the tonearm proper, the counter-wt, and the arm tube/headshell. But perhaps that is not the proper way to think of it, or perhaps the LT components are made of extremely light weight materials. |
The error in my thinking: Yes, the effective mass is high in the horizontal plane, because of all the paraphernalia necessary for the LT function, but it is only affected by the masses of the arm tube, headshell, (cartridge), and counter-wt, in the vertical plane. Many tonearms are similar in that characteristic. |
Hi, The eff. mass was stated as ranging from 14-21gr. since one can exchange the Certal cartridge mounting plates for lighter or heavier types(phenolic, brass,etc...), just as on my "old" arms. The eff. mass is only about 20% higher in the lateral plane vs. the vertical plane. Why? Most of the additional mass(pivoting bar) is near the pivot AND the linkage isn't rigid, but the fluxlines will "bend" if accelerated swiftly(like when the lateral resonance is exited, which, for other reasons is nearly impossible in this design). At the same time, the magnet/guide bar acts a an eddy current brake. "Conventional" linear tracking arms(not the Simplicity and some other pivoted tangentially tracking arms) typically have a 8-20 times(800-2000%) higher eff. mass in the lateral plane..... Hope this helps :-) Have a great weekend, Frank |
lewm: yes the arm, table, platter etc. However the tone arm collar (connecting arm to board) has a triangular structure is this has a ever so slight corkscrew arrangement ..so first point of triangle is highest..next point slightly lower and once again. Apparently this helps nudge. again talking very fine adjustments here and the stylus/arm has compensated for this arrangement... Not sure how I can explain it better....if you got to my system pics...the 6th pic on the top...you can see about 1/2 of this triangled thingy and one of the 3 fine set screws... http://cgim.audiogon.com/i/vs/s/f/1385427538.jpg |
Hi, " Apparently this helps nudge."... Nope... it's just there to "equalize" all forces acting on the stylus. If it was some form of skating-compensation or -generation arrangement(to "nudge" it inwards), an increase of VTF would change the tendency to move either inwards or outwards. But it doesn't... Kind of the same as if you were to raise VTF on an air bearing arm that isn't level. It wouldn't move/accelerate any faster if you were to increase VTF. Solely a question of gravity acting on the entire assembly. Cheers, Frank |
Hi, Nope... - "nudging" the arm towards the center of the record isn't required(that implies poor quality bearings are used...). The triangular base can be adjusted so that there is no tendency to move either inwards nor outwards. One can even compensate for the (very minute) influence of the wiring. Two of the three screws that make contact with the turntable base(apart from the M6 locking screw) can be adjusted, so that the arm base allows for a little more than +/-1° change in horizontal orientation to i.e. compensate for an armboard that's not parallel with the platter. Best, Frank |
So, since you may be listening, Frank, I have often heard knowledgeable people argue about the value or lack of value of having high mass in the horizontal plane. For those who do not like the classical linear tracking tonearms, their very high mass in the horizontal plane is given as one of the problems with such a design. For those who do like them, the same rationale is posited. Further, for the Dynavector tonearms, which also have a higher effective mass in the horizontal plane vs the vertical one, this property is given by Dynavector as an intentional design goal, said to contribute to superior bass performance. What do you think? |
Hi Lewn, "What do you think?" I prefer to refrain from criticizing particular design decisions of other tonearm designers or manufacturers, but I will try to comment( which will, inevitably, contain judgement, I know...). In tangential tracking airbearing arms the disparity between eff. mass lateral vs. vertical is unavoidable, but could be reduced (Rockport, Versa Dynamics...). In order to achive that, the neccesary reduction in eff. length will cause warp wow and pronounced changes in VTA when switching from 120 to 200gr. pressings(to a lesser degree VTF too). Keep the arm longer and you'll have to add a provision for damping: eddy current brake(Dennison, Eminent) or add an anti-resonator(Eminent), all solving one problem for the introduction of one or several others. If the arm cartridge resonance frequency is "split", a key argument by Dynavector, you will now have to avoid exitation of either(more difficult to achieve than you'd think), therefore Dynavector arms feature a massive eddy current brake. The "split plane " design is by no means an invention of Dynavector. Some famous arms(i.e. Gray 106, Shure M16 Dynetic...) preceeded them by decades. Those were used on non-suspended decks(broadcast console-mounted), so the risk of lateral exitation was reduced mainly to what record eccentricity could trigger. And they did it mainly to allow for the use of cartridges that "tracked lighter". Bearing design for such an arm offers options not available to those sticking to "conventional" arrangements(like gimballed arms), so there are potential and in some cases realized advantages. Once you use an arm with a high eff. lateral mass on a suspended deck or, to be found often, on top of a tall rack with tons of gear that is supposed to be rigid(hahaha....think Eiffel Tower with King Kong on the Observation platform swinging happily, huiii!), you'll invite all sorts of problems that may not manifest themselves directly, but through effects such as transformer saturation, increased power requirement or intermodulation distorsion. Besides that, the shift of mass will shift the center of gravity of the deck, forcing it out of a level position. Not exactly desirable for zero friction arms... An Oracle Delphi with ET2 tonearm was a rather popular combination at some time. While it could yield impressive sonic results, I never understood why it was promoted to that degree other than for marketing purposes. The Dynavector's excellent bass rendition predominatly stems from the (eddy current)damping in the lateral plane. It's mass distribution is another reason. Bass below 100Hz is cut in mono, purely lateral... Best, Frank |
A question for Mr Schroeder, On your site you print anti-skate settings for your other arms. You suggest that in between the lead out grooves the arm should move slowly towards the centre of the record. This confuses me, as in-between the lead out grooves, there is less friction than in a modulated groove. Therefore the amount of anti skate required in between the lead out grooves should be less. Then does it not make sense to had a little extra anti skate so the arm moves very slowly towards the outside of the record. Then when the stylus is tracking a higher friction modulated groove the anti skate should be close to correct. Your suggested would have the arm up set with not enough????? Thanks for you potential reply in advance...:-) |
Henry, It's a perfectionist trade-off. With a removable headshell, you cannot have an uninterrupted connection between the cartridge and the phono stage. My experience suggests that the audible difference is far greater with LOMC cartridges than with higher output MM and MI cartridges. Makes sense. Mr. Schroeder made a fair assumption that 99% of those who purchase his tonearm will be using an LOMC cartridge. There's no accounting for nut cases like us, who use MMs and MIs just as much, if not more. On the other hand, I tend to fall in love with one cartridge (regardless of type) and use it for long periods of time, so the slight disadvantage of not having interchangeable headshells is no big deal to me. |
Hello Royaloak, Skating force varies between 4 and 18% of the VTF, depending upon all sorts of factors. Any compensation will result in a compromise. My suggestion is such a compromise, reducing the sidethrust/lateral preload on the cantilever and, at the same time, retaining an amount of skating compensation that will be sufficient to keep uneven stylus/groove wear at a VERY low level. The often described method of using the tracking ability("torture") track on a test record will lead to overcompensation due to the fact that there is no 70µ, 80µ or higher constant modulation to be found on any record. Peaks: yes! Permanent signal: not supposed to exceed 50µ, typically around 20µ. Since modulation causes drag, it will also "modulate" skating, so why compensate for a maximum that rarely, if ever, occurs. Overcompensation will often cause cartridge dampers to assume an asymmetrical position after a while(cantilever no longer parallel with the cartridge body/generator axis). Once you notice that, you ought to send it back to the manufacturer to have it re-aligned. The stylus(when kept clean) usually outlasts the damper/its proper orientation. Try a dynamic Mono(i.e. Sonny Rollins - Saxophone Colossus) record and play the right channel only, then the left channel only. With the antiskating set as high as you mentioned (moving slowly towards the outer edge of the record), you are likely to notice one channel to sound more dynamic than the other. Reduce skating and listen again... All the best, Frank |