Cross-talk measurements vs frequency?

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billshurv

billshurv

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Interesting, that looks quite good. Does anyone have it in stock?


I also found this recently The Secret Society of Lathe Trolls • View topic - Flokason test record finally out for sale. which was cut by someone who makes lathes and appears to have gone the extra mile for quality. But again can't work out how to buy it!


BTW what analysis SW are you using? My biggest issue is I am using the wrong tools. Scott will chide me for not just writing some python code, but he has the 10,000 hours head start on me there :)
 
billshurv

billshurv

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Ah OK, audacity is where I am running into issues. will post an example tonight if I get time away from enjoying my new toy. It may be user error on my part.
 

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billshurv

billshurv

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Thank you. Attached is one of the examples of where audacity gives a confusing result. I haven't tried high pass filtering the file to see if that helps yet, so just need to find time to hunt for samples where there is a clear peak. I only need 3 or for data points to get a view. Then I can try and measure a less good cartridge :).


I found the post below from luckydog before the great purge.

Just to expand a little on some of the consequences that follow the graph I posted above. What matters most to crosstalk/seperation is alignment between the coils and the disc surface. This has different implications for MM and MC carts.

For MM carts, the coils are set in the body, accuracy typically depending on manufacturing jigging and internal fixings. Generally, cartridge body azimuth determines crosstalk. Even if the stylus isn't set straight on the cantilever and so rotates the cantilever slightly on setting down, rotating a MM armature generally doesn't affect crosstalk because the coils don't move and the armature is typically insensitive as to absolute rotation in an MM cart.

In an MC cart the coils sre set on the cantilever, accuracy typically depending on how accurately the stylus is set on the cantilever relative to the coils. If the stylus is not set vertically on the cantilever with dead accuracy, as is very difficult to achieve, then the cantilever and coils rotate slightly on setting down, and crosstalk is degraded.

Then if optimising crosstalk/seperation is the aim, for an MC it's best to do it by signal analysis rather than by dead levelling the cartridge body. And vica versa for MM. Either way, it can be a very sensitive adjustment.

Optimising seperation might well take the stylus off vertical then, and its a matter of which compromise is worse. Depending on manufacturing accuracy.
Click to expand...


I hadn't considered the self centering of the diamond, but that does make sense.
 

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ThomasA

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Thanks for that. I’ve seen that effect which could have two possible explanations both originating from the unpivot tonearm.

1 my player is not level at the moment. Thus any up and down-movement of the tonearm will change azimuth dynamically.
2 it may be the inherent unstability of the unipivot reacting on non- centered records. Stability was significanly improved using a 600 000 cst oil also revommended by Moerch.
 
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