Holy Grail CD-4 Cartridge

QuadraphonicQuad

Help Support QuadraphonicQuad:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Quadzilla

Exiled QQ Veteran
Since 2002/2003
Joined
Jul 9, 2003
Messages
2,193
Location
London, Ontario, Canada
I realize that very few members care about legacy quadraphonic music and equipment, so move along if you aren't interested. I finally found the Holy Grail that I have been looking for … and it was cheap! I had been using an Audio Technica AT15Sa cartridge for CD-4 playback, on a Rega P3 that is heavily-modified and optimized for CD-4 playback. I have a friend who has collected quad gear for decades, and he often makes me offers I can't refuse. I just got a used Audio Technica AT20SL body with a brand new, old stock original ATN20 Shibata stylus.

I will install it tomorrow (it just arrived in the mail today), but I don't really expect a massive improvement over the AT15Sa … it is just that I always wanted an AT20SL ... and it won't hurt to have a spare AT15Sa body kicking around. Oh, and it cost me the Loonie equivalent of US$100 (all-in). I realize that a lot of guys swear by Line Contact and Hyperelliptical stylii, but if you haven't tried a genuine Shibata you haven't really heard CD-4 properly.

P1030618.JPG
 
Last edited:
I realize that very few members care about legacy quadraphonic music and equipment, so move along if you aren't interested. I finally found the Holy Grail that I have been looking for … and it was cheap! I had been using an Audio Technica AT15Sa cartridge for CD-4 playback, on a Rega P3 that is heavily-modified and optimized for CD-4 playback. I have a friend who has collected quad gear for decades, and he often makes me offers I can't refuse. I just got a used Audio Technica AT20SL body with a brand new, old stock original ATN20 Shibata stylus.

I will install it tomorrow (it just arrived in the mail today), but I don't really expect a massive improvement over the AT15Sa … it is just that I always wanted an AT20SL ... and it won't hurt to have a spare AT15Sa body kicking around. Oh, and it cost me the Loonie equivalent of US$100 (all-in). I realize that a lot of guys swear by Line Contact and Hyperelliptical stylii, but if you haven't tried a genuine Shibata you haven't really heard CD-4 properly.

View attachment 43251
My 1st CD-4 cart was the humble AT-12. After a year or so I moved to a much more expensive Pickering some number or other (I liked the record brush). Based on other comments from knowledgeable others maybe it wasn't as good as it should have been, or an equivalent AT.

The Product Directory in the 1974 issue of AUDIO magazine lists the cart at $175. To get it for $100 plus NOS stylus is a great deal. Have fun keep us informed!
 
Alignment is critical, especially with an exotic stylus shape. The new cartridge sounded a bit blah at first … probably the new stylus suspension breaking in, but halfway through an album side it really opened up. I think that it has a wider soundfield than the AT15Sa, but it is hard to say because I couldn't listen to them side-by-side. I didn't have the chance to listen to a CD-4 LP, but that's for tomorrow.

P1030622.JPG
 
I much prefer this over the 15. I bet you will also.
 
Alignment is critical, especially with an exotic stylus shape. The new cartridge sounded a bit blah at first … probably the new stylus suspension breaking in, but halfway through an album side it really opened up. I think that it has a wider soundfield than the AT15Sa, but it is hard to say because I couldn't listen to them side-by-side. I didn't have the chance to listen to a CD-4 LP, but that's for tomorrow.

View attachment 43252
I see you are using the Geo-Disc with a straight line tone arm. I have read it will not work with "S" shape tone arms which I have. Any further info on this? What alignment protractor might be suggested for "S" shape? Thanks!
 
I was having a bear of a time getting my CD-4 setup to work. Years of on and off attempts. What finally got me pointed in the right direction was #1, the Audio-Technica AT440MLa cartridge/stylus combo. Yes, it was expensive but it actually got me going in the right direction. It was lightyears..... repeat: LIGHTYEARS ahead of that piece of shit Ed Saunders Stylus/Cart combo that he was pedaling. I gave that chunk of shit away as it's barely passable for stereo reproduction.

Anyway, #2 was YES, A Geodisc. YES, I have an "S" shaped tone arm but don't believe CNN that they aren't good for CD-4 or are incompatible with Geodiscs. I was finally getting good Carrier Signal and Lock with the above mentioned cartridge, but was getting splatty-sounding demodulation on the left side. I'd tried dozens of "downloadable" cartridge alignment tools with no success. It wasn't until I watched an episode of "Oddity Archive" on Youtube where the host did a demonstration of various stereo cartridge/stylii all aligned with his Geodisc.

So I purchased a Geodisc.

I then learned exactly how far out of alignment I really was! No wonder I had good demodulation on the right and barely any on the left! The cartridge was still skewing off to one side. The Geodisc set me straight and today I enjoy read-to-play CD-4 at the drop of a hat. I barely have to change settings anymore. Just toss on a disc and go. I`m loving it.
 
Alignment is critical, especially with an exotic stylus shape. The new cartridge sounded a bit blah at first … probably the new stylus suspension breaking in, but halfway through an album side it really opened up. I think that it has a wider soundfield than the AT15Sa, but it is hard to say because I couldn't listen to them side-by-side. I didn't have the chance to listen to a CD-4 LP, but that's for tomorrow.

View attachment 43252
I have always felt that if you are not able to point the Geo-Disc accurately to the tonearm pivot point other methods could be more desirable. Depends on the physical construction of the tonearm; in my SME SIII it was impossible.

Perhaps an equally or even more important alignment with CD-4 (and stereo!) albums is VTA, if you use a line-contact stylus (as opposed to a point-contact stylus). You want the stylus long edges to be aligned to and fit perfectly in the groove in order to optimally retrieve the high-frequency modulations. Tangential tracking is directionally also a plus.
 
Last edited:
I have always felt that if you are not able to point the Geo-Disc accurately to the tonearm pivot point other methods could be more desirable. Depends on the physical construction of the tonearm; in my SME SIII it was impossible.

Perhaps an equally or even more important alignment with CD-4 (and stereo!) albums is VTA, if you use a line-contact stylus (as opposite to a point-contact stylus). You want the stylus long edges to be aligned to and fit perfectly in the groove in order to optimally retrieve the high-frequency modulations. Tangential tracking is directionally also a plus.
I'm going to need the guidance of you experienced CD-4 guys when I get my new TT set-up. Hopefully I can reduce the pain by learning from you all (of course learning does set in best sometimes when failure is your teacher!) :cool:
 
Ed Saunders sent me one of his carts free of charge to review. It did not get the good review he had hoped for. I use an Audio Technica AT440MLa and I find it to be a fine CD-4 cart, although it's not spec'd for CD-4. It does the job well. The Saunders cart is only good for stereo.
 
I see you are using the Geo-Disc with a straight line tone arm. I have read it will not work with "S" shape tone arms which I have. Any further info on this? What alignment protractor might be suggested for "S" shape? Thanks!
Scott, I don't see what difference the arm shape wound make. Both type of arms have one pivot point, the S-shape provides offset angle for that arm type, while with the straight arm the headshell is angled to provide the same outcome. Back in the seventies there was a myth that "S" shaped arms had lower tracking error. I remember a turntable add (BIC I think) that showed an "S" shaped arm ovelaid by a straight arm. Both started and ended at the same place but the straight arm being shorter had less mass. I think that the "S" shape became popular beause it looks sexy and the headshells (which are all straight) were all standardized, making swapping cartridges easy. I decided to order a Geo-Disc myself, my main turntable is an Ariston with a straight arm and a Kenwood with the "S" - shaped arm that I set up mainly for CD-4.
 
For what it's worth, S-shaped arms have their mass more balanced between the sides of a line that connects the pivot and the stylus point.
 
Seems like I just ordered the Geo-Disc and it arrived already. I tried it on my straight arm and my alignment was pretty good, could tweek it just a smidge. I tried it on the Kenwood turntable with the S-shaped arm and I see that the cartridge would have to go further ahead and be twisted a bit. Did some quick Googling and found, quote from Audiokarma (Bob_in_OCK)
"Most of the Japanese turntables use an alignment scheme very similar to the Stevenson setup, which results in the cartridge being set farther back than the Baerwald alignment that is common with some protractors. As an example, on a tonearm with a pivot-to-spindle distance of 222mm, the Baerwald alignment is approximately 2mm farther forward than the Stevenson alignment. Both are correct, assuming the cartridge is set to the correct offset angle."
So to use the Baerwald alignment would be difficult if the cartridge can't move far enough ahead, and it would need to be twisted a bit. I guess that's why some say S-shaped arms can't be used with the Geo-disc, but actually it's nothing to do with the shape of the arm just that some arms are a little too short for Baerwald alignment, they were designed with a different alignment method in mind. Which alignment is the best? Which alignment is best for CD-4 is another question. You could easily modify the headshell to space the cartridge farther out if desired and it might look odd mounted a bit crooked, but would it preform better? Anyone care to try?
 
I realize that very few members care about legacy quadraphonic music and equipment, so move along if you aren't interested. I finally found the Holy Grail that I have been looking for … and it was cheap! I had been using an Audio Technica AT15Sa cartridge for CD-4 playback, on a Rega P3 that is heavily-modified and optimized for CD-4 playback. I have a friend who has collected quad gear for decades, and he often makes me offers I can't refuse. I just got a used Audio Technica AT20SL body with a brand new, old stock original ATN20 Shibata stylus.

I will install it tomorrow (it just arrived in the mail today), but I don't really expect a massive improvement over the AT15Sa … it is just that I always wanted an AT20SL ... and it won't hurt to have a spare AT15Sa body kicking around. Oh, and it cost me the Loonie equivalent of US$100 (all-in). I realize that a lot of guys swear by Line Contact and Hyperelliptical stylii, but if you haven't tried a genuine Shibata you haven't really heard CD-4 properly.

View attachment 43251
Good to hear another person is into legacy quad equip and media. That is what my collection is made of. I picked the Audio Technica as the cart to collect and have been looking for a AT 20ss ( my Holy Grail ) to purchase , but haven't found one that is in my price range yet. I do have a AT 15ss w/shibata stylus , in the original box.
My set for CD-4 playback was a Sansui FR 3080 with a AT 15Sa w/Shibata stylus. I am in the process of switching it out to a Sansui (that is the hardware I collect) SR 838 with a AT15ss cart. w/Shibata stylus , but haven't calibrated it yet.
I have used a AT 440mla and thought the sound was great ! But , I too , lean towards the Shibata .
 
Seems like I just ordered the Geo-Disc and it arrived already. I tried it on my straight arm and my alignment was pretty good, could tweek it just a smidge. I tried it on the Kenwood turntable with the S-shaped arm and I see that the cartridge would have to go further ahead and be twisted a bit. Did some quick Googling and found, quote from Audiokarma (Bob_in_OCK)
"Most of the Japanese turntables use an alignment scheme very similar to the Stevenson setup, which results in the cartridge being set farther back than the Baerwald alignment that is common with some protractors. As an example, on a tonearm with a pivot-to-spindle distance of 222mm, the Baerwald alignment is approximately 2mm farther forward than the Stevenson alignment. Both are correct, assuming the cartridge is set to the correct offset angle."
So to use the Baerwald alignment would be difficult if the cartridge can't move far enough ahead, and it would need to be twisted a bit. I guess that's why some say S-shaped arms can't be used with the Geo-disc, but actually it's nothing to do with the shape of the arm just that some arms are a little too short for Baerwald alignment, they were designed with a different alignment method in mind. Which alignment is the best? Which alignment is best for CD-4 is another question. You could easily modify the headshell to space the cartridge farther out if desired and it might look odd mounted a bit crooked, but would it preform better? Anyone care to try?

I always go with Baerwald myself. A quote from a post on this topic in another place

"If you only play inner grooves, Stevenson would be the best. If you only play between the null points, Lofgren would be the best.
If you play entire sides of records, Baerwald is the best although one might argue that any alignment is essentially a compromise which, of course, it is."

I briefly had a thought that since inner grooves can be problematic especially on CD-4, that perhaps Stevenson would be worth giving a try......until I remembered that CD-4 records typically have more deadwax on the inner area than a normal record, which means a Stevenson would be aligning it for best playback in the unused portion of a CD-4 record. So I would definitely stay away from Stevenson when it comes to CD-4 playback.
 
Back
Top