ahh yes label was the word (could not remember, called it stamper) = paper 'thingy' put in the center of the record ( normally song list , titles, duration etc)
any angular graduated scale w some sort of numbering (degrees 0:360 or E,W,N,S etc) and relative dense sub-marks (e.g. every 5-10 deg or so)
any angular graduated scale w some sort of numbering (degrees 0:360 or E,W,N,S etc) and relative dense sub-marks (e.g. every 5-10 deg or so)
agree label will be put at random on the record wrt marker on locked track. However the SW to get the direction of eccentricity will give this wrt the recorded signal - and only reference you have is the marker. So a relative deg count from the marker.
Having a relative scale on record/label of some sort is enough (the numbering I mention is not absolute, just so easier to find say 35 deg vs 25 deg offset from marker) - PROVIDED that marker it self is clearly visible and can be associated w a specific position on such scale on the label
Is not more different that you can identify position of a scratch wrt the orietation of the text on the label. I.e. You have a rough relative direction form text orientation to the scratch orientation
So all that needs to be absolute is the marker is self being visible (if that is not possible well then it another matter - and then yes some sort for extra help is needed)
Having a relative scale on record/label of some sort is enough (the numbering I mention is not absolute, just so easier to find say 35 deg vs 25 deg offset from marker) - PROVIDED that marker it self is clearly visible and can be associated w a specific position on such scale on the label
Is not more different that you can identify position of a scratch wrt the orietation of the text on the label. I.e. You have a rough relative direction form text orientation to the scratch orientation
So all that needs to be absolute is the marker is self being visible (if that is not possible well then it another matter - and then yes some sort for extra help is needed)
Personally I don't see any point in having any marks or scaling on the label. You would need a precise pointer then. A discontinuity (click) on the closed groove signal should be sufficient, the rest i.e. calculating the exact rotation angle, creating a polar plot with degree markings, etc. can be done in software.
I would leave creating that "click" to the end user
I would leave creating that "click" to the end user
Personally I don't see any point in having any marks or scaling on the label. You would need a precise pointer then. A discontinuity (click) on the closed groove signal should be sufficient, the rest i.e. calculating the exact rotation angle, creating a polar plot with degree markings, etc. can be done in software.
I would leave creating that "click" to the end user
yes the SW makes a polar 'Doppler' plot -> from there on estimation of eccentricity axis RELATIVE to the marker =.. x deg , y um
wrt label marking , well point is just a simple aid for those who want to apply the knowledge from the SW to try if any eccentricity compensation would have any benefit in 'cleaning up' the play back signals on the record. If this is done physically by trying to nudge the record a little wrt the spindle (yes might need slight filing of center hole then)- the marking would help in placing direction nudge relative to marker.
Anyway what would it hurt to have say a deg scale on the rim of the label. I see no interference to other uses there?. And what would it hurt to have such a closed groove.. seems there is plenty of room on both side. If someone does not like/see any point, fine .. but I do and like to experiment with this
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Agreed, it may or may not be useful but it certainly won't hurt to have it there, and some smart bunny will find a way to make use of it.
I’ll add to my to-do list for art deliverables.
But wouldn’t the label have to be perfectly adhered for it to matter?
By the same token it can’t hurt to add some markings as labels are inclusive in the price.
Also, aren’t we putting the cart before the horse again?
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say the label is off centered by 1mm and the tick-marks on label are at 45mm radius. At 90 deg from this offset, the 'mis direction/reading' to the 90 deg tick-mark is only atan(1/45) =1,3 deg. So even dense 5deg tick marks may still be useful -and at 10deg tick-marks you'd hardly notice this error.
If we only let the goats pull the cart (like Tor).. we only have conventional material, for conventional use. Unconventional use of conventional test signals surely must have be explored to depth by now. Personally I feel little motivation/use of a yet a test record just doing what already has been done. I'd rather like one crazy idea too many included - than one. Should be enough room as I can see.
wrt other unconventional test record stuff. Seem to remember an old paper (by B&K I think) making a step response signal by cutting an record open (narrow slit) from center to edge and nudging this edge to create a 'jump' in the groove. Would it be possible in another closed groove w/o any modulation - to make such a step response signal?? (don't know if realistic wrt cutting/pressing, but think w starting the cutter at max depth and linearly raising the cutter head through one revolution so just enough groove depth to keep needle in place before the 'jump' 'down the valley'.
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Any "ticks" may drive the flutter meter nuts. To be truly useful, the 3150 Hz track should be a continuous track. I'd like to see it 60 sec long at least. It's not like we are short of room on the LP. If you want to have a locked track at 3150 Hz, that's perfectly fine. The clicks would indicate a precise point in the circle then. Just make them two separate things please.
-Chris
-Chris
thanks - and please one on each side, as eccentricity likely is different for each side.
Now I've been successful in asking for the 'obscure'..'more like more', e.g. bottom of #1612 = unmodulated step response closed/locked grove. Is this something previously been discussed, something you could see a idea in ?(even if out in the 'obscure' again). Just thinking of all plausible signal material not available on already existing test records
Hi All
Picked up the thread again after a while away, I'm on the list for two examples so it's good to see progress. I gave up when there was a lot of back and forth over a subject I'm not going to bring up again
Anyway onto the good stuff ...
Would like your thoughts on this idea - 12" 45rpm instead of 33rpm, will allow better track cutting and higher fidelity - this is well known of 12" singles - also allows a bit of freedom with signal without stepping into the next track. I know it's a bit 'out-there' to have all your setup tracks in 45rpm for something that normally plays at 33rpm and it would require a bit more vinyl for all the tracks but the increase in fidelity / freedom of signal may be worth it ?
OK the above is a bit 'out-there', this one not so much so.
A speed test track cut at 45rpm. Can still be 3150 Hz as the other tracks concerned with rotational speed.
Honestly i'm really not obsessed with 45rpm but it seems we are going to be making/providing one of the better test records made and lots of tables have either motor control or dual pulleys, who's to say that the diameter of the two pulley groves are machined accurately to each other or a speed control doesn't need a resistor change or two. Seems a fairly simple addition for something not seen before (cutter head speed may be an issue)
Thanks
James
Picked up the thread again after a while away, I'm on the list for two examples so it's good to see progress. I gave up when there was a lot of back and forth over a subject I'm not going to bring up again
Anyway onto the good stuff ...
Would like your thoughts on this idea - 12" 45rpm instead of 33rpm, will allow better track cutting and higher fidelity - this is well known of 12" singles - also allows a bit of freedom with signal without stepping into the next track. I know it's a bit 'out-there' to have all your setup tracks in 45rpm for something that normally plays at 33rpm and it would require a bit more vinyl for all the tracks but the increase in fidelity / freedom of signal may be worth it ?
OK the above is a bit 'out-there', this one not so much so.
A speed test track cut at 45rpm. Can still be 3150 Hz as the other tracks concerned with rotational speed.
Honestly i'm really not obsessed with 45rpm but it seems we are going to be making/providing one of the better test records made and lots of tables have either motor control or dual pulleys, who's to say that the diameter of the two pulley groves are machined accurately to each other or a speed control doesn't need a resistor change or two. Seems a fairly simple addition for something not seen before (cutter head speed may be an issue)
Thanks
James
I think eccentricity effects shows up less if the speed tracks are in the first grooves. After all isn’t the purpose to measure and adjust the TT speed and not to see flaws in the record itself?
Hi All
Picked up the thread again after a while away, I'm on the list for two examples so it's good to see progress. I gave up when there was a lot of back and forth over a subject I'm not going to bring up again
Anyway onto the good stuff ...
Would like your thoughts on this idea - 12" 45rpm instead of 33rpm, will allow better track cutting and higher fidelity - this is well known of 12" singles - also allows a bit of freedom with signal without stepping into the next track. I know it's a bit 'out-there' to have all your setup tracks in 45rpm for something that normally plays at 33rpm and it would require a bit more vinyl for all the tracks but the increase in fidelity / freedom of signal may be worth it ?
OK the above is a bit 'out-there', this one not so much so.
A speed test track cut at 45rpm. Can still be 3150 Hz as the other tracks concerned with rotational speed.
Honestly i'm really not obsessed with 45rpm but it seems we are going to be making/providing one of the better test records made and lots of tables have either motor control or dual pulleys, who's to say that the diameter of the two pulley groves are machined accurately to each other or a speed control doesn't need a resistor change or two. Seems a fairly simple addition for something not seen before (cutter head speed may be an issue)
Thanks
James
One disatvantage of 45.RPM is that warp effects on LF resonances will shift in frequency. It may get confusing results that is not representative for 33 RPM playback.