If you could purchase any CD-4 demodulator.....

[kfbkfb]

What is the purpose of having it if you can't play records with it?

I bought it in 2018-05, the above linked info appeared in ~2019.

Possibly even more grim:
http://www.pspatialaudio.com/CD-4 wear.htm^^^
...CD-4 discs made with standard stereo formulation plastic...
...a "physical impossibility" that a conical or elliptical stylus (even tracking at 2g) would not permanently damage the CD-4 FM information...


I'll probably get a 3rd party replacement stylus for my V15 3 and an AT -LP120X turntable.


Kirk Bayne

 

[Doug G.]

Well, I will just say my results do not jive with the scary stuff from that site. I have several old CD-4 records which have obviously been played many times and they still play perfectly in my CD-4 system.

I also doubt the 4.5 gram tracking pressure claim in the article. I remember Lou Dorren claiming a 3 gram figure.

Doug

 

[kfbkfb]

I recall reading the cited AES CD-4 vinyl paper back in the mid-1970s, my first thought was to design a new stylus shape to contact at least some of the upper half of the (CD-4) groove, thereby ignoring the damaged lower half.

Louis Dorren stated that a true Shibata stylus would do this (ignore the groove damage).

https://www.sound-smith.com/articles/stylus-shape-informationThe drawing labeled "TRUE SHIBATA" appears to show that it contacts (some) of the upper half of the groove.


Kirk Bayne

 

[Electric Moo]

That is a good article, thx for the link!

Doug have you ever tried an SAS stylus instead of Shibata, for CD4 playback? Curious if it works

 

[Doug G.]

That is a good article, thx for the link!

Doug have you ever tried an SAS stylus instead of Shibata, for CD4 playback? Curious if it works

I haven't tried an SAS stylus, just several others on other CD-4-designed cartridges. I have always thought the SAS looks a bit delicate and easy to chip which is alluded to in the Stereo Lab article. I'm sure it would have to track CD-4 records just fine with that profile, however.

Doug

 

[Electric Moo]

Just wanted to say thanks for the answer!

Initially I clicked "like", but that's a pretty lazyass way of responding to someone

 

[Doug G.]

The only thing I am better at than being a lazyass is being a procrastinator. Yeah, that's it, that's the ticket! I invented procrastination! (Apologies to Jon Lovitz).

Doug

 

[Owen Smith]

The only thing I am better at than being a lazyass is being a procrastinator. Yeah, that's it, that's the ticket! I invented procrastination! (Apologies to Jon Lovitz).

I bet it took ages to invent procrastination. I mean how did you ever get around to it...

 

[Doug G.]

I could never find a round toit. I only had square ones for many years.



Doug

 

[jupp369]

Been thinking, would be interesting if one could digitally encode a discrete source into CD-4 and feed it into the demodulator

Record from just behind the RIAA Amplifier and play back at the same point, but cut the RIAA output (little switch).
No problem with the level, no readjusting the carrier..

"if-you-could-purchase-any-cd-4-demodulator" I use a SE405 and JVC's 5436, very simple to add the 4 wires.

 

[Doug G.]

If the carrier level controls in the SE-405 are set exactly according to the procedure in the manual, it works perfectly.

Doug

 

[par4ken]

Hi par4ken, don't know what you found, but maybe it's me. I posted a short message before some month..

This was some time ago (many years), it was a complete article with many pictures. The method described sounds exactly like what you are describing. I wish that I could find it again. I don't know if it was your post or not.

Again it is a really cool idea!

 

[jupp369]

This was some time ago (many years) ...

Hi par4ken,
no, that wasn't my post, I postet before a half year.
It seems to be the same idea and works perfectly. I got the idea to it when I remember that all my redordings from Quadradisc were distortet and I try it again with better computer and software. Now I'm happy, but miss a lot of CD-4 records!

Maybe it works this time to upload 2 pictures as example