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Using Test LP - curious observations

I've been tremendously enjoying my Lyra Delos with the Classic for about 1.5 yrs now, and just recently remembered I had the Hi-Fi News Analogue Test LP and got the urge to test my setup.
Here are some of my observations that came as a surprise to me:
1) Anti-skate (Bands 6,7,8,9 on side one) - the cartridge "passed" the test on Band 6 without any anti-skate, but there was audible buzzing coming from the right channel at higher amplitudes. Applying anti-skate made NO difference whatsoever to the results, whether on setting 1, 2 or 3 (most anti-skate). I prefer the sound without anti-skate so this only seemed to confirm that applying anti-skate arguably does nothing to improve the sound and likely makes it worse. It also seems to shed some light on why Harry doesn't like anti-skate.
2) Azimuth (Band 5 on side two) - My preamp has a mono switch so this seemed pretty straightforward. According to the instructions, there should be minimal (if any) mono output if the cartridge was aligned perfectly. Well, there was certainly some output, which immediately worried me, but what really left me scratching my head was the fact that no adjustment appeared to correct it, or make a significant difference. I use the Soundsmith's Counter Intuitive to fine-adjust VTF and azimuth, and after about 2 hours of a wide range of adjustments in azimuth through the CI, it was virtually impossible to determine the optimal azimuth setting, i.e., the output seemed consistently the same regardless of adjustments.

Please free to comment, share your experiences or explain my curious results. Or are they not curious?
actusreus
siranthony
16 posts
 
Nandric,
The spirals get smaller but the speed is the same everywhere on the platter. The only thing that should make a difference is the angle of the stylus as it crosses the record surface. Although I am no expert either, I am a building engineer.
audiofeil
4,011 posts
 
The record is spinning at a constant speed but the linear velocity at the inner grooves is about 50% slower than the outer grooves.

Velocity is defined as the change in distance divided by the change in time. The stylus covers a much smaller distance (remember the record is making one rotation every 1.8 seconds) in one revolution at the end of the record as compared to the beginning of the record.
tonywinsc
583 posts
 
Remember, the skating force is generated by the torque between the stylus and pivot in the horizontal direction acting on the tonearm. This torque comes from the friction between the stylus and the vinyl. It is sliding friction and as far as I know, the magnitude of this sliding friction does not change with respect to groove speed- at least in the range of the beginning to end of the record. It's not like the needle is being pulled through water where viscous drag would be speed dependent. It is more like a skidding car. The skidding friction is constant as the car decelerates and until the car comes to a stop.
dover
2,186 posts
 
Hi all - Antiskate -
"In most turntables, as a result of the angle between the line tangent to the record grooves and a line connecting the stylus tip to the tone arm pivot point, a skating force is developed that tends to force the tone arm towards the center of the record. This skating force is proportional to the above described angle, the tracking force applied to the stylus and the coefficient of friction between the stylus and the record groove. Since the angle is constant for a given turntable and the coefficient of friction is approximately constant for a given stylus, the skating force is then equal to some constant multiplied by the tracking force applied to the stylus."
From the patent on an anti-skating device by Pickering.
This suggests that the anti-skate force required should be constant across the record..
siranthony
16 posts
 
Ok the entire record is going at 33.3 but the outer grooves do cover a longer distance each revolution. So the platter is traveling faster on the outer grooves. But the same amount of information is contained in one revolution on the inner and outer grooves. So there is more packed into a smaller space on the inner grooves. So antiskate would be the same. Thats my best guess anyway.
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