Experiments With CD-4 Units & Cartridges

[Quadwreck]

I finally got around to dealing with a pile of CD-4 demodulators (7 JVC 4DD-5s, 2 Marantz CD 400-Bs), testing with a few CD-4-compatible cartridges (Audio-Technica AT 14S, Audio-Technica AT 14Sa, Audio Technica AT 15Sa, Audio-Technica DR500 LC), here are my abbreviated results:
(Using a Sherwood ST-910B linear-tracking turntable, testing the same song (Nilsson's "Jump Into The Fire" on a CD4 test record from JVC. Each unit had its switches and potentiometers cleaned before testing)
The AT 14S was OK until Nilsson started singing, getting splatter in the rear channels affecting his vocals. Separation good
The AT 14Sa was slightly better, but still some splatter on the vocals. Separation good.
The AT 15Sa was noticeably better, but tracking force was very fickle, a lot less splatter on the vocals, but still an occasional noise. Separation good.
The DR500 LC was the champion, no splatter, and also higher output. Separation good.
As for the units, two of the JVCs were defective, the others were equal in performance, but (to my surprise), one of the Marantz units was better than the JVCs, and sounded better. The other was equal to the JVCs. Not exactly a lab report, but maybe useful to somebody somewhere.
Oh yes, the mix is excellent.

 

[proufo]

I finally got around to dealing with a pile of CD-4 demodulators (7 JVC 4DD-5s, 2 Marantz CD 400-Bs)

Count'em!

That's caring!

Many thanks, Quadwreck!

 

[The Bushmaster]

Quadwreck...Could you explain or discribe what you mean by "splatter"?

 

[Quadwreck]

Splatter is that sound you hear when an AM radio station is not properly tuned in, the radio is just tuned to the edge of the station's bandwidth. That's the distorted sound I was hearing.

 

[The Bushmaster]

Similar to the sound of a worn CD 4 record...Gravelly sound.

 

[Quadwreck]

I suppose, but this was a test record with no wear, and I was only hearing that effect with the vocals, everything else came out fine.

 

[The Bushmaster]

Hummm...That's what I experience on the vocals when they attempt to sing louder, but on just a few that do look well cared for, but well used.

I'm using an AT15SS on a Duel 721 into a JVC 4DD-5.

 

[kevind90521]

Years ago I remember getting "splatter" ocassionally from any of the CD-4 magnetic carts I had installed. But I never got that with the Technics demodulator using the Panasonic strain gauge cart. Are they still around on eBay, etc?

Sent from my SM-G900V using Tapatalk

 

[The Bushmaster]

They show up on ocassion, but are quite costly.

 

[S T Riddle]

Years ago I remember getting "splatter" ocassionally from any of the CD-4 magnetic carts I had installed. But I never got that with the Technics demodulator using the Panasonic strain gauge cart. Are they still around on eBay, etc?

Sent from my SM-G900V using Tapatalk

I've got a JCPenny CD-4 turntable that came with one of those cartridges and a few replacement stylus for them acquired may years back. As I remember it, the cartridges worked well but the turntable was the poor (a BSR design?).

I don't listen to much CD-4 and don't have many vinyls but always wanted to try the cartridge on another demodulator (I acquired one that had strain gauge input but it wasn't functional). I've heard they are a good cartridge, but tracking weight is pretty high.

 

[KevinD9052]

Yes, tracking was high at 2-2.5g as I remember. Maybe more. Less low end than magnetic carts. At the time I considered it a glorified ceramic cart. But it was actually much better than that. And it never distorted. Eventually it became my preferred cart for CD-4. All my vinyl is on a media server these days with the Surround Master handling the decoding. But I sometimes think of setting up my turntable again & resurrecting those CD-4 albums. I miss hearing those original discrete quad mixes.

 

[MidiMagic]

That splatter might be cartridge mistracking.

CD-4 cartridges required higher tracking force than stereo cartridges because the contact area in the groove was larger. Mine tracks at 3 grams.

These are critical items for CD-4:

- Proper mounting position of the cartridge.

- Vertical angle is critical.

- Low capacitance cables.

- Proper level matching to the demodulator.

- Proper tracking force (don't guess).

- Proper setting of the antiskate.

The following are sounds heard and effects noted when CD-4 is malfunctioning:

- Splatter (sudden image shifting or indistinction) is mistracking

- Lack of definition is mistracking pr misadjustment of antiskate.

- CD radar keeps turning off is bad cables, wrong vertical angle, or tracking error.

- Loud snapping sounds indicate the record is dirty.

- a steady hiss like sandpaper being used is a worn record.

- A swooping sound when the record is started from a standstill with the stylus in the groove is normal. The carrier is playing as baseband sounds. You can't slip-cue CD-4.