Are all quad LP formats safe to play on stereo systems?

[i_am_the_sun]

I've generally been of the opinion that quad format LPs were all safe to play on standard stereo systems with no problems or chance of damage to either the disc or the stylus. I've played several SQ LPs on a stereo system and enjoyed the different mixes that the quad LPs often have, albeit obviously not experiencing their quad sound potential.

I recently picked up an unplayed CD-4 LP, released in 1975 by RCA and was reading around the subject on Wikipedia (http://en.wikipedia.org/wiki/Quadraphonic). In the section on Discrete it says that 'CD-4 records could be played as stereo records if care was taken to use a shibata (or linear contact) stylus to protect the subcarrier modulations.'

I am using a Rega Bias 2 cartridge, which is a elliptical stylus. Should I therefore not play the CD-4 LP with such a cartridge, so as not to damage it?

On the LP sleeve itself it simply says that the LP is stereo compatible and makes no mention of only playing the CD-4 LP with certain cartridge types.

Would I be safe playing this LP with a Rage Bias 2 cartridge or should I leave it so as not to damage the LP, until I am able to invest in suitable equipment?

Thanks.

 

[Quadzilla]

I've generally been of the opinion that quad format LPs were all safe to play on standard stereo systems with no problems or chance of damage to either the disc or the stylus. I've played several SQ LPs on a stereo system and enjoyed the different mixes that the quad LPs often have, albeit obviously not experiencing their quad sound potential.

I recently picked up an unplayed CD-4 LP, released in 1975 by RCA and was reading around the subject on Wikipedia (http://en.wikipedia.org/wiki/Quadraphonic). In the section on Discrete it says that 'CD-4 records could be played as stereo records if care was taken to use a shibata (or linear contact) stylus to protect the subcarrier modulations.'

I am using a Rega Bias 2 cartridge, which is a elliptical stylus. Should I therefore not play the CD-4 LP with such a cartridge, so as not to damage it?

On the LP sleeve itself it simply says that the LP is stereo compatible and makes no mention of only playing the CD-4 LP with certain cartridge types.

Would I be safe playing this LP with a Rage Bias 2 cartridge or should I leave it so as not to damage the LP, until I am able to invest in suitable equipment?

Thanks.

Playing a CD-4 LP without a Shibata or Hyperelliptical / Fine Line stylus will damage the subcarrier grooves, but stereo playback should not be a problem. It would be a shame to ruin it though. Mike.

 

[Lucanu]

I think that a good ellyptical stylus won't worn a CD-4 if it's light weight, at least 1.5 grams.
That said, if you go through another cart with a shibata/fine/microline needle you won't worn your cd-4 record and will achieve even better results in stereo playback.

 

[Quadzilla]

I think that a good ellyptical stylus won't worn a CD-4 if it's light weight, at least 1.5 grams. That said, if you go through another cart with a shibata/fine/microline needle you won't worn your cd-4 record and will achieve even better results in stereo playback.

If you say so ... but the prevailing wisdom is that too little tracking force is more damaging than too much ... within reason of course. A lighter tracking force is more likely to "rattle" around the subcarrier grooves and chew them up. 2 grams is recommended.

An elliptical stylus does not ride deep enough into the grooves of a CD-4 LP, and it WILL damage the subcarrier.

Quadfather can likely help us out here. Mike.

 

[jefe1]

Hi,
I've been playing my CD-4 records with a Grado blue cartridge and stylus which appears to be doing a good job of decoding the subcarrier signal. I never thought the stylus might be damaging it since it is not a true shibata type. Does anyone here have any experiance with the Grados?

Jeff

 

[ingresman]

I had a look for a Grado and found this:
http://www.needles-and-spins.co.uk/pd_grado_prestige_blue.cfm
Would this do the CD-4 thing ??, if so £70 is well within my budget.
I've avoided cd-4 for a while as I thought I'd wouldn't be able to get a cartridge I could afford.

 

[Lucanu]

If you can afford 70£ then you can go through the AT440MLa.
http://www.needledoctor.com/Audio-Technica-440MLa-Cartridge?sc=2&category=363

 

[Tubefreak]

My local recordshop has got a CD-4 suitable cartridge (including stylus) for $/€ 89. Nagaoka JT322 (2213)
anyone with experience with that cartridge.stylus?

 

[Cai Campbell]

Personally, I think the whole myth of wearing out the carrier signal on CD-4 record with the "wrong stylus" is exactly that: a myth.

I believe it is perfectly safe to play a CD-4 record with virtually any stylus type as long as the stylus itself is not worn/damaged and the turntable/tonearm are properly configured for the cartridge/stylus employed. The same could be said for any type of stereo or quad record.

The problem is not that CD-4 records can be damaged by the "wrong stylus type", but that demodulation performance is much more sensitive to any damage that the record may sustain via "normal" means (i.e. not by using the "wrong stylus type".)

Given equal amounts of groove damage to a stereo record and a CD-4 record, where the stereo record is played back in stereo and the CD-4 record is played back in quad, the stereo record may sound a little noisy whereas the CD-4 record will give you "sandpaper hell".

Moral of the story is not to worry about the type of stylus you use for STEREO playback of CD-4 records but rather that standard care and feeding rules are followed no matter what stylus shape you have. A properly configured and calibrated turntable with a clean and damage-free stylus of any type will allow you to enjoy your CD-4 records in "stereo mode" without any fear of exceptional wear.

 

[The Quadfather]

I didn't get properly set up for CD-4 for quite awhile. I started with an AT14S, but my demod was a cheap one, and I couldn't get good performance. I gave up on CD-4 though I still collected the records, hoping that someday I would be able to play them. The stylus wore out and got replaced with an elliptical which by then was the only thing I could find which would fit an AT14S. For years, my CD-4 records got played as stereo records with no demodulator. At about the same time, I found my current demodulator, a JVC 4DD5, and a workable cartridge, the AT Trackmaster 8. I then started playing my CD-4 records. They all played fine, for the first time I was able to hear these records the way they were meant to be heard. After stylus break in (about 5 LP plays), I was even able to play known hard to play records like Cat Steven's Greatest Hits. I suspect where this myth got started was when people would play the records on a cheap BSR turntable with a ceramic cartridge. I picked up one record that I had suspected was done this way, and not only were there no subcarriers left, but the record exhibited a tape hiss like sound, indicating play on some rather crude equipment. I doubt that a properly balanced quality turntable with an elliptical stylus and a magnetic cartridge will harm a CD-4 record, but why do it when there are modestly priced microline carts such as the AT440MLa availlable? And why play in stereo, when there are nice demodulators availlable on Ebay still selling for modest prices? It's all about hearing your favorite music in glorious quadraphonic sound isn't it?

The Quadfather

P.S. Since matrix quad records are essentially stereo records, there is no question about their compatibility. There is no subcarrier that can be destroyed.