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berlinta
Posts 4
Joined on 02-10-2010
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Post #:
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19
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Post ID:
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12899
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Reply to:
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12516
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Schröder tonearms, comments from the manufacturer
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fiogf49gjkf0d Dear gentlemen,
My name is Frank Schröder and I'm the guy in the picture. It wasn't taken to show off anything, I actually noticed it after the fact.
I came across this thread by accident and even though I realize that I may be better off forgetting about what I just read, I prefer to address some of the points raised as most of what has been written about my arms in this thread is either incorrect or, at least, misleading.
And while it is not my goal to "convert" anyone, I ask to forego judging technical issues based on personal animosities, particularly when it wasn't me who commited an insult to any other forum member.
Now to the technique(measuring VTF with a Pesola spring gauge, 0-5gr) and technologies(arm bearing, armwand material) criticized.
The Pesola spring gauge is a decent back up, particularly when your digital scale was just dropped on a tile floor from 4 feet.
It does allow to set VTF with a repeatable accuracy of 0.05gr. Not good enough for some carts, but certainly good enough for the modified Denon DL 103 that we were using at the ETF. Thankfully my hand is very steady and the last couple of hundredths of a gram will always be set by ear using the VTF finetuning screw mentioned in one of the posts above.
But, most of the time, I do use a digital scale that's set up to measure exactly at record level.
It is not required to keep the magnets parallel nor does the net flux change when the arm is raised or lowered, be it to adjust VTA/SRA or because the arm needs to ride a warp. As long as there is enough clearance between the magnets(>0.25mm*), they will not touch each other.
The "contouring" of the magnets on all of the SQ arms(can be ordered for all arms) has the following effect: The restoring force generated by the low center of gravity of the counterweight is exactly counteracted by a defined instability in the magnetic bearing, but only for the vertical plane. The stability around the rotational(front to back) armwand axis is further increased at the same time(my arms do not behave like typical unipivot arms). As a result, the VTF doesn't change when altering VTA. The change in VTF has (nearly)nothing to do with the force required to "bend" the thread. That amounts to no more than 0,002p per 5° deflection. The thread is very soft/limp...
All arms that feature a center of gravity that lies below the vertical pivot point will exhibit a change in VTF when altering VTA, some to a far greater extent than any of my "standard" models. Same for arms with spring loaded VTF settings, albeit usually to a smaller degree(they normally are -close to-neutral balance designs: Ortofon RMGs, Breuer..)
Only if you use perfectly flat records exclusively(or a vacuum hold-down platter), the difference between a neutral- and a stable-balance arm won't be audible.
The VTF will change when riding a warp regardless since the arms inertia can't be overcome(some 80s servo-controlled arms came close).
For quite some time I have been using a thread material that exhibits NO stretch, The last batch that took some time to stabilize was used 5 years ago. But since most people on audio forums don't speak from personal experience, but rather tell everyone about their friend's experiences, it will be difficult to correct that now well established idea.
The damping doesn't change when altering VTA since the net flux in the gap remains the same up to the point when the two magnets touch each other(see above*). The magnets are not like "spoons"(but one could build the arm with "nesting" semispherical magnets)
Even though the arm is not rigidly connected to a mechanical "ground", the magnets create an attracting force of up to 12kg(~26lbs). This means that the cartridge needs to generate an enormous force to displace the arm assembly, or, to make it behave "loosely". The bearing which acts as an eddy current brake does add to the resistance to displacement because Eddy current induction is velocity dependent. The faster it moves(read: vibrates, not: moves across the record) the stiffer it appears.
I try very hard to avoid creating any "Voodoo" cult, my arms are not supposed to have a sound, but rather to allow the cartridge to do it's job as a transducer in an undisturbed fashion. That's why the arms are designed to deal with all the energy "fed" into the armwand assembly right there, with no dependency upon the mounting surface for energy dissipation or having to worry about impedance mismatches between arm and turntable base. Very little energy being generated or picked up by the turntable will find it's way back to the armwand and the cartridge.
The armwand/counterweight assembly is a transmission line allowing no energy to be reflected back to the cartridge.
Dear Stitch,
I've been building tonearms since 1976 and sold the first arms abroad in the late 80s. I don't post other than to correct obvious errors, I don't advertize in any printed or internet magazines, nor do I kiss up to any reviewer when they show up in our room at CES, RMAF, etc...
I believe you have posted elsewhere to express your dissatisfaction, even if it may be a second hand experience. Like before, all I can offer is advice if the customer isn't getting what he was hoping for. But 8 out of 10 audiophiles are like the proverbial men who don't read manuals. They know everything(because they've owned everything, but are never satisfied) and if they don't get that new toy to work well immediately, it's the toy that's flawed.
I don't sell to people on forums now and I sold arms before there was the Internet. People call me after listening to a system with a vinyl front end that included one of my arms. They liked what they heard, that's it. But I don't shy away from direct comparisons to other top contenders. I own or owned nearly all of them and certainly used all of them at some point.
Maybe we could get together someday and I can demo how easy it is to set up my arms. All it takes is to throw some "established" wisdom overboard and listen(no Voodoo involved, just physics).
Romy,
You may not get along with Mr. Weiss, but you may have greater respect for Stig Björge(Lyra), J.Limon(EMT), Masaki Ashizawa(Kondo), Heiner Martion(Martion Audiosysteme)... and literally dozens of manufacturers and professional musicians who use my arms.
Most of them use LOW compliance cartridges, with armwands with a fairly high eff. mass. And it makes a tremendeous difference if you just add mass at the headshell to increase eff. mass or whether you use that mass to increase stiffness AND internal damping accordingly.
The pricing is an old and somewhat boring topic. But I'll let you decide. My arms each take between 25 and 70 hours to make(from scratch). The dealer markup isn't higher, but rather slightly below industry standard. Still, any dealer/distributor makes way more money on each arm than I do. Add to that the patent fees, travel cost and time spent answering emails, doing the taxes... Cost of the raw material accounts for ~ 25% of the wholesale price(you do the math). So, yes, I don't get rich, I get by. But I still love what I'm doing and if anyone doesn't, then there are many other choices from designers I highly respect: Allen Perkins, Mark Doemann, Micha Huber, Bill Firebaugh, Bob Graham, Franc Kuzma...
@ Stitch again,
I'm always fascinated by people who make a person or an item their enemy without ever having met their imagined foe. But where you get your information from beats me. I hope that you at least retained the ability to enjoy this hobby and maybe even music per se.
Lastly, to Romy:
I've owned and used SME 3012 arms in various iterations between 1979 and 2005 when I finally sold the last of what I still consider an Audio classic. But, as good as it still is, there are better arms out there. That doesn't mean it can't be the best choice for your system, for your preferences, your taste. It appears it is.
Good night and good luck,
Frank
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