Another Very Unconventional Turntable

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lenjack
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Re: Another Very Unconventional Turntable

Post by lenjack » 05 Mar 2019 13:58

vaporware = unobtanium?

chgc
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Re: Another Very Unconventional Turntable

Post by chgc » 05 Mar 2019 15:46

Sort of. To my understanding, unobtanium implies a material (like “titanium,” only with imaginary properties), or maybe something that actually exists or existed but which is practically unobtainable (like a fully compatible replacement stylus for a Shure V15 LT?). Vaporware, on the other hand, is more like a product that never got beyond the marketing department and into the market.

H. callahan
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Re: Another Very Unconventional Turntable

Post by H. callahan » 06 Mar 2019 09:31

chgc wrote:
05 Mar 2019 10:13
Judging by the thick and inflexible looking tonearm wire, it would seem that the tonearm isn’t meant to be advanced by the groove itself. I assume that the infrared sensor is supposed to enable some sort of drive mechanism to accurately advance the stylus, but the Kickstarter page seems to lack pictures or any description of a tonearm drive mechanism. While such a mechanism would be genuinely innovative, in my opinion, I’m afraid the project does smell rather strongly of vaporware.
Yes, thinking about it the tonearm needs to have some sort of drive if there is a track-selecting-feature, as it is said to be on this tt.
But drive mechanisms for linear arms are very hard to build - unless you accept rumble each time the arm does advance to compensate for tracking error. There have been several attempts in the 80s, but quite some had problems. A good implementation usually does require some space for the drive mechanism and i doubt there is enough space in this wheely-thing for that.
Furthermore i´m pretty sure that such a kind of linear arm drive allready has been built in the 80s, so i don´t think its truly a new invention - and if it was it would be a plus to tell on the kickstarter but they don´t.
...

Apart from that off-center-records can be a problem with (very) short linear arms if the arm cannot move forward and backward. Depending on the off-center hole of the record and the length of the linear arm the arm must be able to also move backwards, otherwise it would start to skip. And as this linear arm is very short it better had the ability to also move backwards during replay, not only for track-selection.

chgc
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Re: Another Very Unconventional Turntable

Post by chgc » 06 Mar 2019 11:56

Indeed. While a drive mechanism for a linear tracking tonearm isn’t new, one that uses an ir sensor to keep the stylus centered in the groove would be the sort of innovation that 21st century electromechanical technology might enable. Lacking any sort of tonearm pivot in the plane parallel to the record surface (as the pictures suggest) the control and actuator system would have to be very fast and precise. I’m guessing that a working prototype of this turntable— one that actually plays records— doesn’t yet exist.

H. callahan
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Re: Another Very Unconventional Turntable

Post by H. callahan » 07 Mar 2019 05:21

Sorry for also taking this down, but i think there allready have been linear tts in the 80s which could identify individual tracks on a record. I seen one which had about 10 or even 12 buttons just for track-selection and -programming. I think one could make it play like track No. 2 - No.5 - No.3 - No.7 etc. , so similar to a cd-player.
These linears also needed to have some sort of sensor for track-recognition and this tt also had a dark lid, which had to be closed for playback as the linear arm was incorporated into the lid - so its likey that those linears allready had some sort of IR-sensor.

Apart from that speed of arm-movement on a linear isn´t that critical. They can move very fast, or say fast enough to even correct for a record having an off-center-hole being 1mm off. The arm then has to move 2mm in total, but it does have about one second for that. And 2mm in one second isn´t that fast. A linear arm has to move faster on the lead out for example.
The problem rather is that the arm has to move a lot faster in comparison to just compensating for tracking error on a record having a corretly placed center hole - and the faster the arm has to move the more vibrations and therefore rumble may be produced.
This probably also is the reason for the makers of the Wheely using wood for the linear arm, as wood at least does reduce vibrations a little better than metal would - wood is a little more self-damping.
...

Another problem with this arm is that it doesn´t seem to have any pivot as you indicated. This means if there is a malfunction, like dirt on the IR-sensor or something else, there is no clearance for anything. The stylus might scratch across the entire record because the sensor is "blind" - and it will be done before you are able to morse-code with the center-stick to stop it.

chgc
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Re: Another Very Unconventional Turntable

Post by chgc » 07 Mar 2019 15:30

No worries, HC.

One 80’s turntable with infrared track programming and a lot of buttons was the Technics SL-15. In the SL-15, an ir sensor was used to locate the gaps between tracks. I’m not aware of any widely available turntables that used ir sensors to actually track the groove (I don’t know if that would even be possible).

An SL-15 does not rely on the drive mechanism to make the myriad small adjustments necessary to, for example, adjust for a slightly off center hole. The drive mech puts the tonearm in the right general vicinity and the horizontal gimbal allows the stylus to follow the groove. When the tonearm gets displaced a small amount from perpendicular to the guide rail, an optical sensor in the tonearm assembly tells the drive mech to advance the tonearm. If there were no gimbal to allow the tonearm to follow the groove in this way (as appears to be the case with the Wheel), the drive assembly would have to be constantly and quickly reacting to keep the stylus in the groove.

Sorry if my description is unclear or inaccurate, or if I misunderstood your comments. I’ve never actually laid hands on an SL-15, although I am familiar with the SL-10 which is similar.

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Re: Another Very Unconventional Turntable

Post by Spinner45 » 07 Mar 2019 18:15

chgc wrote:
07 Mar 2019 15:30
No worries, HC.

One 80’s turntable with infrared track programming and a lot of buttons was the Technics SL-15. In the SL-15, an ir sensor was used to locate the gaps between tracks. I’m not aware of any widely available turntables that used ir sensors to actually track the groove (I don’t know if that would even be possible).

An SL-15 does not rely on the drive mechanism to make the myriad small adjustments necessary to, for example, adjust for a slightly off center hole. The drive mech puts the tonearm in the right general vicinity and the horizontal gimbal allows the stylus to follow the groove. When the tonearm gets displaced a small amount from perpendicular to the guide rail, an optical sensor in the tonearm assembly tells the drive mech to advance the tonearm. If there were no gimbal to allow the tonearm to follow the groove in this way (as appears to be the case with the Wheel), the drive assembly would have to be constantly and quickly reacting to keep the stylus in the groove.

Sorry if my description is unclear or inaccurate, or if I misunderstood your comments. I’ve never actually laid hands on an SL-15, although I am familiar with the SL-10 which is similar.
Yes, a linear tonearm must have some "wiggle room" horizontally, in order to activate the drive system via optical sensor(s).
A second optical sensor provides "pulses" that are generated by a moving slotted disk, the microprocessor "counts" these pulses to determine where the arm is, and if the "end of record" requires lifting and resetting the arm, and shutting off the unit.
The "counts" can also be used to determine size of record and setdown point.

chgc
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Re: Another Very Unconventional Turntable

Post by chgc » 07 Mar 2019 18:39

Interesting. I wondered about that slotted disk. Thanks.

fscl
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Re: Another Very Unconventional Turntable

Post by fscl » 07 Mar 2019 19:09

Basically as mentioned, this unit has been done before in a different form / factor........:-k

The tonearm hid a drive platter in keeping with the Walkman (portable #-o ) theme :-k :-k :-k

Sony's Flamingo series:

https://www.vinylengine.com/library/Sony/ps-f5.shtml

https://www.vinylengine.com/library/Sony/ps-f9.shtml

In the case of The Wheel, the platter hides the tonearm, which I imagine is pretty close to the Flamingos, using an AT 95E as the cartridge and updated with a brain that will look for song separators and allow FF-FRW for direct access to previous / next tracks.....:-k :-k :-k

Modern funding / financing via Kickstarter to manufacture ...... =D> =D> =D>

Current fleabay search for the Flamingos are outta this world...... :shock: #-o

Fred

H. callahan
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Re: Another Very Unconventional Turntable

Post by H. callahan » 08 Mar 2019 04:22

chgc wrote:
07 Mar 2019 15:30
No worries, HC.

One 80’s turntable with infrared track programming and a lot of buttons was the Technics SL-15. In the SL-15, an ir sensor was used to locate the gaps between tracks. I’m not aware of any widely available turntables that used ir sensors to actually track the groove (I don’t know if that would even be possible).

An SL-15 does not rely on the drive mechanism to make the myriad small adjustments necessary to, for example, adjust for a slightly off center hole. The drive mech puts the tonearm in the right general vicinity and the horizontal gimbal allows the stylus to follow the groove. When the tonearm gets displaced a small amount from perpendicular to the guide rail, an optical sensor in the tonearm assembly tells the drive mech to advance the tonearm. If there were no gimbal to allow the tonearm to follow the groove in this way (as appears to be the case with the Wheel), the drive assembly would have to be constantly and quickly reacting to keep the stylus in the groove.

Sorry if my description is unclear or inaccurate, or if I misunderstood your comments. I’ve never actually laid hands on an SL-15, although I am familiar with the SL-10 which is similar.
No problem, i think your description is correct. I also think i now understand what you mean: If there is no clearance because of the tonearm not having any pivot, the tonearm needs to have a sensor for detecting any tracking error.
And you´re right, if the tonearm doesn´t have any pivot it needed to have some sensor being able to detect the groove the stylus is tracking. Too bad there aren´t any pictures or explanations of the arm drive of the Wheely.
But maybe this also is the reason for the Wheely not having made it yet.