""The eliptical stylus was developed in the 1960s in recognition of the fact that for a pivoted tone arm, a spherical stylus would not maintain contact with the same points on the disc as the radial arm cutter""
I agree.
As long as the spherical stylus is normal to the plane of the disk, it will contact the same lines.
Why is a pure conical geometry called a sphere?
As an aside, has anybody ever tried to modulated the antiskate force based on signal amplitude?
Cheers, John
The skating depends also on modulation.
My spheric tip tracks as good as possible with 2,5 gramms and NONE! Antiskating, since the arm/pickup combo has really high mass.
With a 12 " Arme it would be better anyway.
The cone is called spheric, because the tip is round with radius apx. 16 mikrometer.
A small departure from the present subject, but closer to the original Blowtorch thread, is an article just published in the IEEE 'Solid State Circuits Magazine' Winter 2011 Vol 3. NO.1
Jan will most probably be most interested in this article:
It is called: 'Circuit of Life How I became a better analog designer' by Willy Sansen
I knew of Willy Sansen, and knew that he was one of the best analog designers out there. Unfortunately, I don't remember meeting him, even though he was a TA for Dr. Bob Meyer when I attended a few of his classes at UCB.
Another interesting thing was a photograph of Willy with Barrie Gilbert and Dr.Temes, (someone who I used to work with at Ampex Research in 1969.) at Lausanne, Suisse, very close to where I used to live. I had no idea that they educated electronic engineers there, at least that high level.
Now that is the sort of designer I admire. I could learn from him!
Jan will most probably be most interested in this article:
It is called: 'Circuit of Life How I became a better analog designer' by Willy Sansen
I knew of Willy Sansen, and knew that he was one of the best analog designers out there. Unfortunately, I don't remember meeting him, even though he was a TA for Dr. Bob Meyer when I attended a few of his classes at UCB.
Another interesting thing was a photograph of Willy with Barrie Gilbert and Dr.Temes, (someone who I used to work with at Ampex Research in 1969.) at Lausanne, Suisse, very close to where I used to live. I had no idea that they educated electronic engineers there, at least that high level.
Now that is the sort of designer I admire. I could learn from him!
The skating depends also on modulation.
Back in the day, I had occasion to use 12 inch singles, 3 to 4 minutes per side, 45 rpm, with modulation so high that I could almost hear the needle on the groove even with the several kilowatts of bass and midrange working full tilt. I had a heck of a time figuring out how to adjust the skate such that all the records played. Course, once scratching became de-rigour, running the cart at 5 to 6 grams was a requirement..and it no longer mattered what you did with the anti-skate.
I've not been able to figure out how to adjust the antiskate on my dual CD player though. For some reason, the instructions on the Denon 1700 neglected that..
Same with the Ipods now..go figure..It was a kinda rhetorical question. I know the contact plane is circular regardless of location, but am not sure if the vertical contact is linear, or some curve as well..The cone is called spheric, because the tip is round with radius apx. 16 mikrometer.
Cheers, John
This conforms with my own experience and the experience of some other audiophiles I know.
Which reminds me again the saying of my friend: "Vinyl records 'make music', while CD's do not".
I agree that MCs can sound better. Often they do not and are zippy bastards nerving the listener , the superdupervdh or whatever stylus make them able listen to the dust in groove and the scratches at the surface.
MC are a mechanical non balanced mass/spring system due the kind of suspension of the cantilever.
We have a resonance depending of tip mass, vinylelasticity of the record and damping rubber of the mc and hardness of the suspension.
(MM are mass balanced by construction and when well made, they sound very good indeed and are affordable.)
Now, if we can control the MC Resonance we can fix one problem.
This can be done partially with parallel resistance at the MC Imput.
This can be done very good with aluminium cantilever breaking the resonance up and we have a pretty flat response up to 30 Khz and more.
Hard cantilevers (boron etc)do this not and resonate at apx. 25 - 30 khz, so it must be damped by the tonearm and suspension only.
But : to much damping kills the sound. Now the most MCs have a raising frequency response up to 6 dB and more a in this area, because you must choose between to evils.
Many audiophile think this brightness is air in the music or simply they can no more hear it.
The other thing, MMs have no pole shoes, MCs with pole shoes have a concentrated magnetic field there were the generator coil is.
Thus lesser strayfield loss = more precision.
Thanks John, I will try to get that article.
I've read several things of Dr. Sansen; he is indeed a very gifted designer and teacher.
As far as I know he is still teaching here at Leuven University (close to Brussels) but is more into analog chip designs than discrete circuits.
jan didden
Hi John,
You're absolutely right about Willy. He is a great designer and a true gentleman to boot. I see him just about every year at ISSCC.
BTW, anyone here going to be at ISSCC this year? Scott?
Cheers,
Bob
OHHH, Pavel, i forgot. It´s on this weekend. No, i can not make it. That´s a pitty.
Here is some work about gain boosting and regulated cascodes :
http://analoglib.net/tag/regulated-cascode/
Here is some work about gain boosting and regulated cascodes :
http://analoglib.net/tag/regulated-cascode/
This year's International Solid State Circuit Conference is being held in San Francisco on February 20-24. You could hang out in the lobby for free, maybe someone will drop their badge. Health care is the big topic this year surprise, surprise.
I'm sticking with the CD when it comes out, and I get to watch on the web for free, no more analog versions.
Get a press pass! Write an article, get in for free and get paid for going. You know who to ask.
99% of the attendees probably don't pay out of their own pockets. It costs me >$800.
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