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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
dover
2,263 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.
nandric's avatar
nandric
4,086 posts
 
I owned the Sony PUA 237 some 30 years (?) ago but still
remember this peculiar 'bias compensator'. To refresh
my memory better I checked by the Vinylengine. Just one
quote from the user manual reg. 'bias compensator': 'In
conventional method ,M' is applied as a constant force. Therefore ,the side thrust is canceled out at ONLY few positions on the record.'

Regards,
moonglum
619 posts
 
Excellent post Tony...I'm thinking of another possibility for variances in behaviour.
The same mechanism that VPI often use for antiskate - twisting of the arm cable - may have been unintentionally applied by manufacturers (or indeed by DIY owners) of other tonearms during arm cable-forming.
This could generate either a counter-force or worse, a complementary force?
I'm suspicious of the VPI solution as I can see it causing stress related micro-vibration in much the same way as clamping vinyl. But this is only an opinion....
Best regards,
dougdeacon
3,338 posts
 
The last possibility that I can think of why the cartridge might sound better without AS is tonearm geometry set-up. We must use our protractors to set the HTA and VTA in a static situation. That means that while the cantilever is loaded in the vertical direction (VTF) it is not loaded in the horizontal direction. That slight difference could be audible to some.
Quite true, it's certainly audible to me. Any change in horizontal loading produces a change in SRA. That's one parameter that I (and some others on this thread) adjust for every LP we play.

Perhaps some tweaking is required to compensate. When I am setting up my tonearm position, I pull on the platter to load the stylus in the horizontal direction as I position the tonearm.
Exactly right, though it's tricky to do accurately if using a high resolution protractor like the Mint.
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