(1975) CBS Quad LP Insert

[barfle]

Full disclosure. Other than the digital formats, I have never played quad in any format than SQ. QS hadn’t shown up in the marketplace by the time I bought my Sony SQD1000, and I couldn’t afford to pretty much replace my entire signal path to go CD-4. Any other formats at the time were peripheral to the discussion, and again weren’t setups I could afford. Eventually, I found a Tate, which worked well until the right front channel died, and I put my Sony back into the system. And then I pretty much replaced everything with a home theater setup, which I use today.

Along the line, I picked up QS and a CD-4 decoders, but in five or six years, they’ve never been plugged in. I have no idea it they work, but included in my bucket list is getting them working and building adapters somI can connect them to my Marantz 7701 digitally. Not this year, and I’d be surprised if it was next year. All stuff I want to do, but right now the room build is still in progress (cold weather means the wood- finishing in the garage is taking a lot longer), but I have confidence that the shelves will be done in a week unless some other crazy crap gets in the way.

I recently got my record collection (see avatar) out of its shipping boxes. The records are on the shelves, but in “unpacked” order, which means I have many days of sorting and filing. And, of course, my turntable was wrecked by the movers, so there’s another shopping experience ahead of me.

I’ll never get done, but I’ll stop when I’m dead.

 

[MidiMagic]

Then look at Japan. While JVC, and CBS/Sony only released in their own systems, many other record companies used whichever system best suited a particular recording.

Too many companies tooki "blackmail" from art5ists who wanted a certain system.

Hearing a working CD-4 system certainly HAD to have impressed a newcomer to quad a heck of a lot more than any matrix system. I know it did me.

What about the claims by matrix adherents that a CD-4 record was ruined in one play on a regular stereo system? Patently false.

Doug

I have never heard a record played from beginning to end in CD-4 without problems. One time I was listening to a CD-4 record in a stereo store and a woman ruined the rendition when she put powder on her face using a mirror beside the turntable. Immediately the snapping pencils crashes started.

CBS used to hammer Sansui about the QS mono downmix (LB and RB are down ~8dB), I guess they didn't consider QS much of a competitor by 1975 since they just have the one "insult" stating that SQ has Complete...compatibility.


Kirk Bayne

SQ has the same trouble for CB and anything between LB and RB.

Only SQ "survived" well into the eighties and with the proper backing of the Tate system it could have thrived. It's so sad that all the money was with Dolby. Dolby drew on both SQ and QS and created an inferior "bastard" system. They also took the backdoor into audio via movies/video!

QS didn't really survive at all. Involve simply picked up the pieces of long abandoned technology but I am thankful that they did that.

Actually, Dolby Surround is 100% QS, except that the DS channels are halfway between the QS channels. It is the Dynaco Diamond on steroids. I was using a QS decoder to decode DS before I knew it was DS. I thought the record companies were using QS for three years.

When it gets down to it, I love ALL quad systems as long as they are quad. I just feel the need to defend CD-4, sometimes, from what I feel are unfair criticisms of the system that works so well for me.

Doug

I'm glad it works for you. It never worked for me.

 

[Aging quadie]

I have a few dozen CD-4 LPs that I bought nearly a half-century ago. I also have two JVC demodulators (one still in the original carton) and a couple of vintage Sansui QRS receivers. Never mind the nude shibata cartridges and low capacitance cables, I have never been able to properly play any of those CD-4 records, be they from RCA or WEA.

 

[Marcsten]

Full disclosure. Other than the digital formats, I have never played quad in any format than SQ. QS hadn’t shown up in the marketplace by the time I bought my Sony SQD1000, and I couldn’t afford to pretty much replace my entire signal path to go CD-4. Any other formats at the time were peripheral to the discussion, and again weren’t setups I could afford. Eventually, I found a Tate, which worked well until the right front channel died, and I put my Sony back into the system. And then I pretty much replaced everything with a home theater setup, which I use today.

Along the line, I picked up QS and a CD-4 decoders, but in five or six years, they’ve never been plugged in. I have no idea it they work, but included in my bucket list is getting them working and building adapters somI can connect them to my Marantz 7701 digitally. Not this year, and I’d be surprised if it was next year. All stuff I want to do, but right now the room build is still in progress (cold weather means the wood- finishing in the garage is taking a lot longer), but I have confidence that the shelves will be done in a week unless some other crazy crap gets in the way.

I recently got my record collection (see avatar) out of its shipping boxes. The records are on the shelves, but in “unpacked” order, which means I have many days of sorting and filing. And, of course, my turntable was wrecked by the movers, so there’s another shopping experience ahead of me.

I’ll never get done, but I’ll stop when I’m dead.

Well I am an SQ fan overall as well. My Tate is the backbone of my system at home. In my vacation place I have a Sony SQD 2070 and I find it does a much better job than I expected! If your turntable was wrecked, then now is a good time to get a modern table with a modern cartridge and take a run at CD-4!
As for QS, if you have a variomatrix decoder such as the QSD-2 (or 1) such as I do, it works very well. Main issue there is there just wasn't a ton of source material that I liked. Sound like you have your work cut out for you!

 

[barfle]

Well I am an SQ fan overall as well. My Tate is the backbone of my system at home. In my vacation place I have a Sony SQD 2070 and I find it does a much better job than I expected! If your turntable was wrecked, then now is a good time to get a modern table with a modern cartridge and take a run at CD-4!
As for QS, if you have a variomatrix decoder such as the QSD-2 (or 1) such as I do, it works very well. Main issue there is there just wasn't a ton of source material that I liked. Sound like you have your work cut out for you!

My old cartridge is a Shure V15 Type 5 MR, which supposedly will trigger a CD-4 decoder. As with all the other things that need attention in my setup, it's going to have to wait a while.

I also have a 78 stylus for that cartridge, so I intend to hang on to it for a while. I may well end up with two turntables, but who knows. Heck, I'll take a shot at fixing the old one. I'm pretty handy with some of that stuff, but as with the Tate, I haven't had a chance to look at it. But I did get my '79 VW super beetle back on the road this year!

 

[Marcsten]

My old cartridge is a Shure V15 Type 5 MR, which supposedly will trigger a CD-4 decoder. As with all the other things that need attention in my setup, it's going to have to wait a while.

I also have a 78 stylus for that cartridge, so I intend to hang on to it for a while. I may well end up with two turntables, but who knows. Heck, I'll take a shot at fixing the old one. I'm pretty handy with some of that stuff, but as with the Tate, I haven't had a chance to look at it. But I did get my '79 VW super beetle back on the road this year!

Congrats on you bug!!! Awesome little cars. I am an old car guy myself, although I am a British car guy. Sunbeams, Jags, that sort of thing.
As to your Shure, I believe the MR stylus will track CD-4s although perhaps others know better. Where you may have trouble is in the frequency response. A CD-4 cart needs to go to roughly 40k to get the 30K carrier consistently, or so I have read. I think your Shure may go only to 25K per this review. If that's the case, it may trigger the light on your demodulator, but it won't work well. Shure V15 V-MR phono cartridge Specifications

 

[Doug G.]

A CD-4 cartridge needs to have a frequency response and acceptable separation to at least 40kHz, at a bare minimum, to, ideally, 50kHz to be able to recover the modulations/sidebands of the 30kHz carriers. Lighting the radar on a demodulator is just the start. It doesn't mean a cartridge will provide satisfactory, distortion-free CD-4 reproduction. It only means the cartridge can recover a 30kHz signal of sufficient strength for the demodulator circuits to detect it.

This is one of the basics that needs to be understood for successful CD-4 reproduction.

Trivia: What were the two most obvious features of the Super Beetle differing from the previous regular Beetle?

Doug

 

[kfbkfb]

SQ has the same trouble for CB and anything between LB and RB.

I haven't worked through the math, but, IIRC, SQ quad -> mono lost CB but maintained the sound level of content near CB (between LB and RB).


Kirk Bayne

 

[MidiMagic]

Well I am an SQ fan overall as well. My Tate is the backbone of my system at home. In my vacation place I have a Sony SQD 2070 and I find it does a much better job than I expected! If your turntable was wrecked, then now is a good time to get a modern table with a modern cartridge and take a run at CD-4!
As for QS, if you have a variomatrix decoder such as the QSD-2 (or 1) such as I do, it works very well. Main issue there is there just wasn't a ton of source material that I liked. Sound like you have your work cut out for you!

Actually, if you count all of the Dolby Surround material (including unmarked soundtrack albums mentioning only the Dolby Stereo in the movie credits), there are more QS compatible records than any other system. For 4 years, I thought these records were using the Quintaphonic system the Who used, because I heard surround and had no info on the existence of Dolby Surround until 1980. None of the stereo magazines mentioned it. I got the info from Peter Scheiber.

A CD-4 cartridge needs to have a frequency response and acceptable separation to at least 40kHz, at a bare minimum, to, ideally, 50kHz to be able to recover the modulations/sidebands of the 30kHz carriers. Lighting the radar on a demodulator is just the start. It doesn't mean a cartridge will provide satisfactory, distortion-free CD-4 reproduction. It only means the cartridge can recover a 30kHz signal of sufficient strength for the demodulator circuits to detect it.

This is one of the basics that needs to be understood for successful CD-4 reproduction.

Trivia: What were the two most obvious features of the Super Beetle differing from the previous regular Beetle?

Doug

The CD-4 system needs a carrier bandwidth of 15KHz to 45KHz.

I haven't worked through the math, but, IIRC, SQ quad -> mono lost CB but maintained the sound level of content near CB (between LB and RB).


Kirk Bayne

I have done the math extensively and have encoded recordings.

The QS system has a 3dB difference LF to LB and RF to RB.
The QS system has an 8.3dB difference from CF to LB and CF to RB.
The QS system has an 0.7dB difference from LB to CB and RB to CB.

As a sound is panned from CF to CB (via either CL or CR) in QS, it diminishes smoothly down to nothing during the entire pan with mono playback.

The SQ system has a 3dB difference LF to LB and RF to RB.
The SQ system has a 3dB difference from CF to LB and CF to RB.
The SQ system has a 3dB difference from LB to CB and RB to CB.

As a sound is panned from CF to CB (via either CL or CR) in SQ, it diminishes by 3 dB from CF to LF (RF), remains constant from LF to LB (RF to RB) and diminishes smoothly down to nothing while moving LB (RB) to CB with mono playback.

 

[Doug G.]

Without "help", all matrix systems are greatly compromised as far as separation is concerned.

Doug

 

[par4ken]

I do not consider Dolby and QS to be the same thing! There are just as many similarities to SQ. It doesn't take rocket science to add some out of phase information to a stereo signal. Both SQ and QS decoders did an excellent job with original Dolby Surround. Dolby surround was inferior to both original quad systems. Dolby front encode coefficients are the same as with SQ and regular stereo. The rear encode coefficients, even those of Dolby PL are similar to QS; not exact, but close. Low pass filtering and Dolby B encoding of the surround information was intended for optical movie soundtracks and is an abomination for music!

I maintain that Dolby both original surround and PL although related to both QS and SQ, is still a very much different animal. Our old friend OD considers Dolby to be similar to and descended from SQ (and not QS). While I still don't accept his hypothesis he now claims to be in possession of an official Dolby document that validates his position. He claims that all the internet published encode information for Dolby is wrong! I'm sure that it is true that Dolby did pay CBS for patent infringement and tried to blur that fact. Hopefully OD will share at least some of his "new information".

https://theqmatrix.wordpress.com/

 

[par4ken]

Without "help", all matrix systems are greatly compromised as far as separation is concerned.

Doug

Yes they obviously are but that misses the point. The fact that the idea worked at all has always fascinated me! Even those very basic early decoders, even the Dyna speaker connection was a fantastic improvement over regular stereo! Not to mention the need for stereo enhancement, even with discrete you still need a decoder for stereo!

 

[Doug G.]

Don't get me wrong. I still love all of it, despite any shortcomings. My first experience was with a Hafler set up and I was hooked. And then a universal decoder my company produced, with an amplifier for the back speakers and I loved that. Gradually worked toward more sophistication and it's been about 50 years.

Doug

 

[kfbkfb]

Issue 1:
Panasonic and JVC made CD-4 turntables - CD-4 cart (properly aligned) + CD-4 demod -> 4 line level outputs, upon reflection, this seems like a very good idea for mass market systems, the only maintenance needed was to keep the stylus clean and replace it when worn out (if the CD-4 demod had auto F/B separation & carrier level).

Issue 2:
I was thinking about an SQ encoded sound placed exactly between LB and CB (or RB and CB) and the SQ quad -> mono downmix.

Issue 3:
Dolby Surround encoding seems overly complex, IMHO, they should have mimicked DynaQuad and encoded S w/0 and 180 degree phase shifts in Lt and Rt rather than +/-90 (either way, S will cancel out in mono).


Kirk Bayne

 

[Larry Geller]

V15s decode CD4 just fine. I used them for years. Still had end of side distortion, but they all did.

 

[MidiMagic]

Without "help", all matrix systems are greatly compromised as far as separation is concerned.

Doug

I have never looked for separation. What I want is an equal image for a sound coming from any direction around the listener. I never want to hear images jumping from speaker to speaker (unless it was deliberately recorded to do that).

I do not consider Dolby and QS to be the same thing! There are just as many similarities to SQ. It doesn't take rocket science to add some out of phase information to a stereo signal. Both SQ and QS decoders did an excellent job with original Dolby Surround. Dolby surround was inferior to both original quad systems. Dolby front encode coefficients are the same as with SQ and regular stereo. The rear encode coefficients, even those of Dolby PL are similar to QS; not exact, but close. Low pass filtering and Dolby B encoding of the surround information was intended for optical movie soundtracks and is an abomination for music!

Right. But when you look at the stylus vectors that are put on the record, Dolby Surround puts the same modulations on the record that QS and Scheiber do (using a position encoder, not the 4-corners encoders for any of these).

For music, the low pass was not used. And PL-I and PL-II did not use a low-pass on playback.

I have been encoding since 1970, and when I use my RM position encoder, the sound positions are identical in QS and DS playback.

I maintain that Dolby both original surround and PL although related to both QS and SQ, is still a very much different animal. Our old friend OD considers Dolby to be similar to and descended from SQ (and not QS). While I still don't accept his hypothesis he now claims to be in possession of an official Dolby document that validates his position. He claims that all the internet published encode information for Dolby is wrong! I'm sure that it is true that Dolby did pay CBS for patent infringement and tried to blur that fact. Hopefully OD will share at least some of his "new information".

https://theqmatrix.wordpress.com/

An SQ decoder does a good approximation of DS decoding. The sound positions are all in almost the right place. But an SQ decoder can do the same thing with a QS record.

The patent infringement was for using their logic chips in circuits in early versions.

Funny, but I thought at the time if I bought ECG replacement chips, I could design anything I wanted with them.

Don't get me wrong. I still love all of it, despite any shortcomings. My first experience was with a Hafler set up and I was hooked. And then a universal decoder my company produced, with an amplifier for the back speakers and I loved that. Gradually worked toward more sophistication and it's been about 50 years.

Doug

My first was also using the Hafler Diamond in July 1970. Six months later I encoded a set of sound effects for a stage play that used the Hafler Diamond as the decoder. I am not sure, but I think that was the first ever use of matrix quadraphonics in a stage play.

Issue 1:
Panasonic and JVC made CD-4 turntables - CD-4 cart (properly aligned) + CD-4 demod -> 4 line level outputs, upon reflection, this seems like a very good idea for mass market systems, the only maintenance needed was to keep the stylus clean and replace it when worn out (if the CD-4 demod had auto F/B separation & carrier level).

Somebody gave me a Panasonic RD700 with a built-in CD-4 demodulator. But the cartridge in it is not a CD-4 cartridge and the wrong spindle (for a BSR overarm changer) was in the spindle compartment. There was no single play spindle.

Issue 2:
I was thinking about an SQ encoded sound placed exactly between LB and CB (or RB and CB) and the SQ quad -> mono downmix.

The same thing happens to a QS -> mono downmix.
Hafler, EV, Scheiber, and DS do this too.
The only matrix systems that do not do this are BMX (UMX), UD-4, H, and UHJ.

Issue 3:
Dolby Surround encoding seems overly complex, IMHO, they should have mimicked DynaQuad and encoded S w/0 and 180 degree phase shifts in Lt and Rt rather than +/-90 (either way, S will cancel out in mono).

Kirk Bayne

Actually the only difference between the Hafler diamond, QS, and DS encoding (ignoring the Dolby B and the low pass) is where to put the phase reversal hole

Hafler put it between the B and R speakers.
Scheiber, Gately, and EV put the hole between LB and RB.
QS cut it in half and put one between LF and LB, and the other between RF and RB.
DS cut it in half and put half between L and B and the other half between R and B.

The 90 degree phase shifts effectively cut the hole in half.

My position encoder lets me move the hole to where it is not in the way of a pan.

 

[TVB]

I am disappointed that I never got the above advertising sheet with any of my SQ records. Was it packaged with a record? On a side note, I love my SQ collection but I LOVE LOVE LOVE my cd-4's. Cd-4 was problematic until I got an old school Audio technica AT 15SA cartridge and I was blessed when I found a JVC cd-4 demod that was brand new.

 

[kfbkfb]

Cd-4 was problematic until I got an old school Audio technica AT 15SA cartridge and I was blessed when I found a JVC cd-4 demod that was brand new.

What turntable do you use?

Was aligning the cartridge for CD-4 difficult?


Kirk Bayne

 

[TVB]

Hi Kirk, I bought a VPI scout. The arm seems to be a little more adjustable than your standard table and you can buy high capacitance cables as they just plug into the table. Adjustment isnt any more difficult than any other table, just be as accurate as possible and get a stylus pressure gauge. On this table turning the counterweight a tiny bit to the right or left changes the position of the cart in that direction, so you can square the cart perfectly to the record. I also took off the mat because I get better sound without it (tracking angle is better). I know i could probably mess with the tracking angle but I believe once you get proper decoding ---don't mess with it! I just bought a bunch of Baggys CD4's and back channels are fine. The rumour that CD4 back channels are easily damaged is highly overstated in my opinion.

 

[Doug G.]

It's not just the back channels that are dependent on the super sonic signals. All four channels are.

Doug.