Kuzma Stabi

[_Scotty_]

BobM,I am running a Maplenoll Ariadne TT which has an air bearing platter and tone arm and I not running into tracking problems or dust problems you describe. I run a 1 micron inline air filter on the air supply and the arm assembly is self-cleaning, dust is blown off by the air escaping from the bearing. 
 Of course friction is not a problem. The arm cartridge combo will sail through HFNRR test record Band 8, 300Hz tone L+R,+16dB at 1.4gr tracking force and Band 9 can be negotiated with 1.55gr of tracking force. The arm is far from perfect in many areas but dust and mis-tracking are not on the to do list.
Scotty

[topround]

I want that Kuzma 4 point, but I can't afford one so I bought this:


Vinyl is so addictive, I took my boys to a record store today and bought some records, if I won lotto I would have bought the whole damn store.
It's like candy
and it sounds so damn good, setup right with the right gear
and there is no turning back, and it is not about what is better cd or vinyl, its an emotional connection.
And to be honest there are times listening to music ,even in my shitty car, that goosebumps arise all over my arms and thighs,my body gets cold,  God it is wonderful, whatever makes those goosebumps rise, whatever media does it for you, just make them rise, because at that point you have reached the point that makes sense of it all. And what this all about, a true high, a high that makes you want to dance, or fist pump, or swoon, or cry, that is what this whole insane hobby is supposed to be about.
I spent two hours at a  record store today with my boys. God knows we all spent time at record storesbuying records or cd's, I really miss those stores, they were a large part of our cultural landscape that is now gone for the most part,  unfortunately.

sorry for the rant...I had a music filled day last night today and it was great!

[_Scotty_]

If I read your post right topround you bought the Dynavector 505. I have always wanted to hear that arm but I have never been anywhere it was in use. I suspect it is under-rated and the engineering solutions it uses mis-understood in many cases. It looks like THE arm to use with a Dynavector Karat.
Scotty

[topround]

I should get it next week, I use Micro Seiki TT's and the 505 is supposed to be a good combo with these tables.
Cartridge?...that is still up in the air, but the Dynavectors that i have heard I liked, unfortunatley I can't afford them

I might try a Uwe 103 I have the stepup trannies for that

The 505 is supposed to sound very nice from what I have heard from people that owned the arm, other think it is a crazy design,proof will be how it sounds to me in my system, but those upper end dynavector cartridges are delicious sounding

[tmazz]

BobM,I am running a Maplenoll Ariadne TT which has an air bearing platter and tone arm and I not running into tracking problems or dust problems you describe. I run a 1 micron inline air filter on the air supply and the arm assembly is self-cleaning, dust is blown off by the air escaping from the bearing. 
 Of course friction is not a problem. The arm cartridge combo will sail through HFNRR test record Band 8, 300Hz tone L+R,+16dB at 1.4gr tracking force and Band 9 can be negotiated with 1.55gr of tracking force. The arm is far from perfect in many areas but dust and mis-tracking are not on the to do list.
Scotty

I don't think Bob was trying to imply that these things happen with all linear tracking arms but rather was discussing the kinds of problems that an engineer must overcome when designing a linear tracking arm. It can and has been done successfully by a number of companies but it is tricky and expensive to do right. Which is why in spite of the theoretical advantages of a linear tracking system, the technology as all but disappeared from the consumer electronic space with the exception of a few high end applications. LT arms were all over the place in mid-fi TTs in the 70s and 80s, but the mechanical complication proved to be more trouble  than it was worth in the mass market consumer product lines.

[tmazz]

Thanks Mike. Crazy price for crazy fun right? Still less than a Ferrari. 

What's amazing is the difference that the increased radius from needle to pivot makes to the sound, while the actual angle changes are extremely small. I guess tracking angle is very sensitive. Why hasn't linear tonearms research continued? Or swing arms with mechanical geometry that holds the stylus in perfect tracking? Masters are cut with linear arms, right?

Our Mike has this Stabi/Stogi rig and I've heard it couple times, sounds really great.   I always loved the look of it.

Rich,

The swing arm technology you are talking about was develped by Garrard in the late 60s for their Zero-100 TT,



The rod on the outside of the arm pivoted the headshell as the arm move across the record to maintain the "prefect" tracking position. While this was nice in theory, it caused multiple other problems. First, it was a rather crude mechanical system so the odds of it maintaining the ideal position to the tolerances that we know today are so critical are slim to none. (the last time Nick at AudioVisions (RIP - both Nick and the store) worked on my tonearm the last adjustment he made was to the VTA, the adjustment screw he moved had 32 threads per inch and when moved it about 1/8 of a turn everything just locked in and it was like a whole new TT. Now this means that an alignment change of 1/8 of 1/32 of an inch made a significant difference in SQ. There is now was the mechanical system in the Zero-100 arm could maintain those types of tolerances.) The system also introduced two more friction points (where the headshell is attached to the main arm and where the control rod is attached to the headshell. Friction at either of these points could impede the free movement of the system to the point where the angles are not maintained or noise in introduced into the arm. And lastly the whole system flies in the face of the rigidity that we now know is so important to high end tonearm performance. A nice idea in theory, and it might ave even been beneficial given the SQ of the TTs of the day, but not something that would work in today's high end TT space. I think that is is another one of those cases where the medicine is worse than the original illness.

Listed below is a link to a white paper on the physics behind the Zero-100 idea.

http://www.quadibloc.com/science/freq03.htm

[richidoo]

Thanks Tom!! There is nothing new under the sun.

With the .004" adjustment of your VTA making such a huge difference, there is obviously a demand for a live automatic adjustment for it, which is what the 4 point does (I think?) But like you said, to pull it off, you must enter the realm of extreme mechanical engineering and price no object parts. Plastic consumer type construction will not fly now, when TTs are the nearly exclusive province of audiophiles who choose vinyl for the sound quality.

[_Scotty_]

While the design of my tone arm is appears deceptively simple and some of the basic problems have been addressed, I would like to see greater rigidity in the arm wand.
 I think one the big drawbacks to the air-bearing design is the implementation of the pressurized air supply and dealing with the potential noise the compressor may generate. I bought my Maplenoll TT back in 1995, used, without an air supply and had to design and build my own fortunately with the invaluable help and suggestions from LLoyd Walker.
 I wound up using a dual diaphragm pressure/vacuum pump from Gast with a 70dB noise level. This has to placed in a closet in a back bedroom with a 100ft. airline to the table to attenuate the noise level to usable levels. 
 Most people want a plug and play TT and don't want added complexity of maintaining the air supply to the arm.
Scotty

[topround]

My Micro Seiki has a vacuum for holding down disks to the platter and an air bearing for the 24 pound platter.
The pump is dead silent, the only way you know it is on is by looking at the light. Silent like 0 db silent.
Seems like they should be able to make them silent today if they could do it back in 1981?

[_Scotty_]

All it takes is money and a good sales volume to guarantee a return on the investment to put the design into production. Micro Seiki had those two things back in the day. Also Micro Seiki always had good engineering.
 I got by for about a $600.00 dollar investment in the air supply including the materials included in the construction of dual air pulsation damper tanks required by the bearing systems. Maplenoll never had the capital necessary to implement an elegant no compromise solution to the air supply demands of their bearing designs.
 I actually have more $$$ in the damn air system than I have in the TT itself. I can't complain much though as I have put considerably less money into the vinyl side of the hobby over the last 20 years than I have put into the digital side.  Vinyl hasn't had the same kind continuous advance in technology that rendered my digital front end obsolete every two years.
And I don't have an acute case of nervosa just a low level chronic problem requiring an occasional injection of technology.
No Denial here.
Scotty

[topround]

some pics of the micro pump

[richidoo]

Can't see the motor, but good idea to use heavy glass bottles for reservoir, the walls are very stiff and easily damped by the foam. There is a label to the right of the barbed nozzle. What does that say? Can you see the labels under the metal pump belly between the springs?

I'm working on a diy rcm, like to know what kind of pump it is that's so quiet. Linear air pumps are usually the quietest of the common types, but not dead silent. 

[topround]

http://www.amp8.com/amp-etc/record/micro/sx8000_2.htm

here is a link to a guy in Japan that takes gear apart and rebuilds the whole thing from scratch practically.
He takes lots of pictures, this is a rebuild of a Micro 8000 a very expensive table

[BobM]

I don't think Bob was trying to imply that these things happen with all linear tracking arms but rather was discussing the kinds of problems that an engineer must overcome when designing a linear tracking arm.

exactly Tom. It takes money to get the design right. But then that's true of most things.

[richidoo]

That's cool, thanks. Couldn't see the labels, but fun read anyway...