Electrical Azimuth adjustment- aka crosstalk

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Gold
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Joined: Sat Dec 01, 2007 5:20 pm

Re: Electrical Azimuth adjustment- aka crosstalk

Post by Gold »

billshurv wrote: Sat Sep 08, 2018 8:47 pm
Random notes on alignment. The usual method of azimuth alignment is to play a vertically encoded track and adjust for a null. Of course most test tracks only have a 300Hz vertical track on them so this doesn't necessary help much and also doesn't address stylus azimuth, which gets critical for certain stylus shapes. But vertical adjusted for null and horizontal adjusted for max should give the same answer, so that certainly seems a good way for live adjustment electrically.
I think that is a good way to do it electronically. I would use tones instead of music. The least amount of crosstalk will be at 1K so I'd use a 1K tone.

On a first read seems to have useful tests in for checking stylus azimuth but not sure it does anything for generator azimuth measuring.
I don't think that is worth worrying about unless you plan on making your own test record. You just have to decide the record you are using is the truth. I think the most accurate test record currently available is Flo Kaufmann's Flokason Test Record.

The AES compendium was mentioned. I wrote this on DIY Audio but the AES publications should be subtitled "Weird, Wacky and Esoteric papers". All the important work was doe before the AES existed. All the good stuff is in the H.E Roys "Disc Recording and Reproduction" compendium. Shhh, no one knows about that book.
billshurv
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Re: Electrical Azimuth adjustment- aka crosstalk

Post by billshurv »

Funny you should mention the test record but a small group of us are trying to do exactly that. It's herding cats TBH mainly as the one person who knew how to specify the tests in a meaningful manner threw his toys out the pram over IP issues. We'll get there eventually :).

Some has just sent me a frequency scan off an ortofon test record so I can see how things vary over frequency at least on a sample of one. This is with a Shure V15 with JICO SAS, which on first glance appears rather good for an aftermarket stylus.

I like weird and wacky, but it's always good to go way back and realise how much of this was all worked out a long time ago, and at least on the reproduction side completely forgotten in the rush for new and shiny :)
billshurv
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Re: Electrical Azimuth adjustment- aka crosstalk

Post by billshurv »

Well headed off down a rabbit hole discussing cross-talk sources and trying to work out what is most significant. Still no conclusions but an interesting data point came up trawling some old data sheets
DL-107 cross-talk.JPG
This is the cross-talk curve of the denon DL-107. An old design, but the shape is probably seen in a lot of cartridges. Interestingly it appears to be the inverse of the trackability curve and suggests that the main source of out of phase cross-talk could be mistracking. If this is the case then it's possibly level dependent and therefore a pain to correct, at least in the analog domain.

More investigation required, but so far seems that Foz is right and azimuth correction can be done with fixed level, but it's a minor part of the problem.
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mediatechnology
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Re: Electrical Azimuth adjustment- aka crosstalk

Post by mediatechnology »

The "bathtub" crosstalk curve is what I recall seeing in countless Hirsch-Houck Labs cartridge reviews over the years.

Yours is unique in that it shows L-R and R-L curves.
I've never seen that level of detail.
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