What causes "splatty"/sandpaper sound?

[captainwrong]

OK, I'm getting closer to CD-4 nirvana, but I have some questions still. I'm getting good seperation and the radar light and all that biz, but now I'm getting the splatty sound. I'm not sure what's the cause, so maybe someone can help me track it down.

Is this a symptom of not having the carrier level adjusted correctly? (I don't have a test record, so I've been adjusting by ear with music records.) Is this because I'm using an eliptical stylus (Grado Red)? (It seems to work fine, and the stylus only has about 10 hours on it.) Is this due to the records being worn? Or is my 4dd-5 to blame? Tracking force? Cartredge allignment (though I've been careful about setting this up)?

Any thoughts?

 

[sqdave1975]

Probably due to the cartridge I fear. I have a collection of carts, all mounted on headshells to enable quick changes. I have a Nagaoka MP-11 boron (elliptical) an Audio Technica AT14sa (shibata), an Audio Technica AT331LP (microline) and a vintage Osawa Moving Coil with boron cantilever (fineline).

In test, only the AT14sa and AT331LP give acceptable results with CD-4, the AT331LP having the edge over the AT14sa. The AT331LP also had to go through a "break-in" period before it reached CD-4 perfection.

The AT331LP offers the best results possible at a low cost. Buy one (or more) now and save yourself a load of grief !

 

[captainwrong]

That was kinda my hunch, though I am wondering if the records are part to blame. Seems like I'm getting terrible results with WEA labels (Roberta Flack "Killing me Softly" and Zappa "Apostrophe" specifically.)

 

[sqdave1975]

Maybe a contributing factor. The Roberta Flack LP is (apparently) a notoriously bad pressing. My first copy of "The Best of The Doors" played horrendously. I bought another copy of it and that was fine. I can only assume that the carrier signal was worn on the bad copy. Not knowing the history of the record it's possibly been damaged by a worn or incorrect stylus. So yes, we shouldn't discount the records themselves. Visually the "bad" Doors LP looked fine. So you can't really tell without playing them on a known working CD-4 setup!
You wil get there in the end, it just takes patience and time !

 

[Cai Campbell]

You will be surprised at how well "hard-to-play" CD-4 records will play once you get the right cartridge/stylus. A line-contact type stylus is crucial for proper CD-4 performance. There ain't no shorcut here.

 

[The Quadfather]

What is happening is the stylus is skating over the finer modulations in the groove. it isn't maintaining contact with the low part of the modulation. This is because your elliptical stylus is not thin enough to fit down into the dale of the modulation at speed, or maybe not at all. The result is a distorted subcarrier that cannot reproduce a difference signal properly. The distorted mess you wind up with is that "splatty" sound, and it is common in CD-4 systems that haven't found CD-4 nirvana. I recommend the Audio Technica AT331LP cartridge. Get it from jandr.com for a modest $45.00 . Then you turn the separation pots down and adjust the carrier level for the cleanest sound. Adjust slowy, and you might have to pause and listen between slight adjustments when it is close. When you get the difference signal right, (it will sound hollow, but not distorted) you turn up the separation pots and adjust for best separation, which occurs when the main audio matches the difference audio equally in level, not all the way up. Incidently, track at about 2 grams, not 1.5 as advertised.

The Quadfather

 

[captainwrong]

You guys were right, but you knew that already!

Still tweaking the adjustments and all, but so far, I'm even getting decent sound out of that Roberta Flack LP! Plus my Yamaha deck seems to like this AT cart better than the Grado I was using.

 

[The Quadfather]

I have only one or two quadradiscs that don't play well, and those appear to have been damaged possibly by being played on a cheap turntable with a ceramic cartridge. I have other copies of these discs that play fine. Even my Cat Stevens Greatest Hits disc plays well, a disc known for it's difficulty of play. So keep at it and you will achieve CD-4 nirvana. Lots of separation and no splatter. CD-4 is a good system, and was much maligned in it's heyday, because of the inferiority of many stylii and cartridges that were sold as CD-4 compatible in the seventies. Even the good ones weren't that good, and the line contact stylus that was developed at the end of the quad era, has saved CD-4 from the fate of being "half baked coming out of the oven". If you bought the AT331LP and you play the stylus for awhile you will notice it improves as it wears a little bit. Theis "breakin period" is short, and the result is supreme. Remember, track at 1 3/4 to 2 grams, a little heavier than recommended. The stylus will skate at 1 1/2 grams. Happy Listening!

The Quadfather

 

[captainwrong]

Yep, I'm there. CD-4 nirvana! Ahh!

I'm really amazed at how good it all sounds! The surface noise is kind of more pronounced, but that's ok. But wow! I can't believe this format didn't take the world by storm!

 

[sspsandy]

Since CD-4 is a format that gives you higher resolution in the sound, any imperfections in the vinyl will be more pronounced. I actually have a couple of CD-4 discs that are virtually flawless, and the highs and lows are really clear. Anytime you upgrade your system with a higher quality cartridge, or better speakers, the ticks and scratches get magnified a bit, but you're hearing more of the music. If the disc has some crackle, you can always cut back on the treble or turn on a high filter, although I tend to increase the treble and bass as far as permissable in general. I'll take a little background noise over flat sounding music any day.