May be of interest to some: http://www.electronicdesign.com/ana...m=email&elq2=117d1eb4027947cb87e299f09b9a0803
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Engineering Review of a High-End Turntable
- Thread starter DonH56
- Start date
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- Tags
- turntable phono
restorer-john
Grand Contributor
Interesting, thanks for posting.
The article however seems to have been regurgitated for a while. This one has more detail:
https://www.semiconductorstore.com/...-Motion-Control-An-Engineers-Perspective/2916
It does sound like marketing department speak though, no detail whatsoever on the turntable's drive system*, specs or anything. Basically, it appears to be copy for promoting the stepper drive chipset for anything needing 'stepless' precision (3D printers etc)
Here's the original 'white paper' note some of the dates on the DSO screen grabs (2014)
edit: I looked it up. Belt drive, one with an idler/tension wheel.
The article however seems to have been regurgitated for a while. This one has more detail:
https://www.semiconductorstore.com/...-Motion-Control-An-Engineers-Perspective/2916
It does sound like marketing department speak though, no detail whatsoever on the turntable's drive system*, specs or anything. Basically, it appears to be copy for promoting the stepper drive chipset for anything needing 'stepless' precision (3D printers etc)
Here's the original 'white paper' note some of the dates on the DSO screen grabs (2014)
edit: I looked it up. Belt drive, one with an idler/tension wheel.
Last edited:
Interesting. When I first started to read it i was wondering how they were going to quiet the stepper motors.
OP
- Thread Starter
- #5
I was hoping for more technical detail and the summary was a let-down. Pretty much an infomercial for the stepper company, wish I had read it in more detail before I posted it but oh well.
I tend to think an analog control loop would be a better solution but then again I am an analog guy... I wonder how they determine positioning to keep the tip centered in the groove? The schemes I have seen in the past ranged from some sort of torque feedback from the arm to fancy control based on average signal levels to optical sensors on the head for tracking. Not something I have ever done but have been curious about.
I tend to think an analog control loop would be a better solution but then again I am an analog guy... I wonder how they determine positioning to keep the tip centered in the groove? The schemes I have seen in the past ranged from some sort of torque feedback from the arm to fancy control based on average signal levels to optical sensors on the head for tracking. Not something I have ever done but have been curious about.
There was some reference to a laser I thought so might be an optical method.
cjfrbw
Senior Member
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- Mar 5, 2018
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'Using precision laser optics and an advanced control algorithm, the 90-degree angle of the stylus is permanently captured and maintained. "
Interesting, since the cutting angle of vinyl can vary up to 20 degrees. How is a perfect 90 degrees going to help you there? Also, 90 degrees to what? It measures the fluctuating groove and re-aligns the stylus actively?
Interesting, since the cutting angle of vinyl can vary up to 20 degrees. How is a perfect 90 degrees going to help you there? Also, 90 degrees to what? It measures the fluctuating groove and re-aligns the stylus actively?
restorer-john
Grand Contributor
Me too. I've always believed a holistic (I hate that word) approach to linear tracking could be a game changer. I've worked on/repaired hundreds of linear tracking TTs, most designed in the late 70s/ early 80s just when CD hit, and the budgets for analogue were no doubt just about to be curtailed somewhat.. (under statement if ever there was one.)
There were two basic designs, DC motor, reduction worm drive, via a 'dial string' arrangement. (with a heavily decoupled medium rev. shock mounted DC motor) or linear motor driven designs (Pioneer/Sony etc). There were (in my opinion) flaws in each, but the simplest systems seemed to sound the best. (I never tested them back then).
Pretty much all the decent ones used an optical vane arrangement to stimulate lateral movement and that, in itself was difficult to keep tracking error to a minimum as it was all analogue and prone to drift. Often, LT turntables had a worse tracking error than a pivoted arm.
I have a bunch of linear tracking TTs from that era in my storeroom, so I can revisit them anytime if anyone is interested down the track.
Me too. I've always believed a holistic (I hate that word) approach to linear tracking could be a game changer. I've worked on/repaired hundreds of linear tracking TTs, most designed in the late 70s/ early 80s just when CD hit, and the budgets for analogue were no doubt just about to be curtailed somewhat.. (under statement if ever there was one.)
There were two basic designs, DC motor, reduction worm drive, via a 'dial string' arrangement. (with a heavily decoupled medium rev. shock mounted DC motor) or linear motor driven designs (Pioneer/Sony etc). There were (in my opinion) flaws in each, but the simplest systems seemed to sound the best. (I never tested them back then).
Pretty much all the decent ones used an optical vane arrangement to stimulate lateral movement and that, in itself was difficult to keep tracking error to a minimum as it was all analogue and prone to drift. Often, LT turntables had a worse tracking error than a pivoted arm.
I have a bunch of linear tracking TTs from that era in my storeroom, so I can revisit them anytime if anyone is interested down the track.
I have a Technics SL10(purchased new), and a Pioneer PL-L1000 that I need to service after a time in storage. Are you on top of those? I have the service manuals but being able to discuss things with a hands-on guy would be great.
restorer-john
Grand Contributor
Absolutely, no problem at all. I've had several PL1000s and 1000a TTs and have worked on many. I've even got a few spare 1000a motor units.
You'll find some posts on AK from years back where I've discussed specifics, but happy to help here either via PM on in the forum.
