Quadraphonic records (LPs to you and me)

also, i forgot to mention that c-d 4 needed a demodulater for the c-4 records. the 'sq' needed a decoder that would be installed on the bottom of my marantx receiver. i'm not sure wheather the 'qs'. form needed anything.

i bought my first system during the 4 chanell era. i bought a marantz 4300. back then you had 'sq' c-d 4 and qs. 'sq and qs' did'nt need a special cartridge. but c-d 4 did. 'c-d 4 needed a stylus that would reach up to 40,000 hertz. that's when the audio technica came out with their 'shibata 'stylus. it was an 'at15 or an at20. i beleive the 15 cost 100 dollars and the 20 was 150 dollars. i bought the 15. 'sq a needed a decoder with full logic, front to rear to have the best separation. i'm not sure about 'qs'. when i had my system i bought an album that would start with testing your c-d system. it had a tone that would signal the 4 chanells as a test to hear if your 4 chanells were working. one thing i remember is that the more plays you had on a c-4 album. the noise would increase.

So you might recommend playing  a quad stereo lp on a normal set up?
Whereas someone else said it would be less due to lost components

It's also worth noting that quad pressings are also mixed specifically for the format, and upon 2-channel reproduction can range from absolutely explosive (try a quad UK of Dark Side of The Moon) to the utterly bizarre (US quad pressing of Steely Dan's Can't Buy a Thrill).  I like buying quad pressings since you can often get a slightly different mix that brings out  buried elements of the production, and generally they sound quite good.

Why do you need 7.1 if you’re playin’ stereo vinyl at home ?

I do not have at the moment a separate 2 x  mono preamp (one however is being built for me bespoke by Tom  Evans)
So the phono goes into my sp3 where it is decoded into 7.1 - which separates the signals into excellent splits around surround speakers. It does not just "surround" the sound but splits them up in a good way. E.g in Mandolin Wind there are 3 guitars that in stereo sound like one or maybe two (dependent on the speakers!). The Bryston splits those into different speakers so you can hear quite distinctly. Often also percussion is separated to hear the decay of those items well as they are often coming out of a surround and not L or R. Great for me as I used to play in an orchestra and I love being "in" the sound rather than face a wall of it.
Not many companies' products do this. Bryston and Lexicon do very well and Chord did some time back

I had a 4 channel system; you need a 4 channel pre-amp, a 4 channel amp, and 4 speakers to get the full benefit of a 4 channel record; it produces something akin to surround sound.


  https://www.google.com/search?q=phase+linear+4000&oq=phase+l&aqs=chrome.3.69i57j0l5.17975j0j...


You will also need a 4 channel amp


      https://www.google.com/search?q=dynaco+qsa+400&tbm=isch&source=iu&ictx=1&fir=1kHUCYG...:


It was a system I enjoyed for many years. Although not high end in the sense I enjoy stereo high end today, it was fun.

@tatyana69

The Bryston very successfully codes 2 channel into 7.1.
I never play analogue into stereo

Why do you need 7.1 if you’re playin’ stereo vinyl at home ?

Proper stereo set-up reproduce holiographic 3D imaging and this is all about analog, you don’t need another speaker on the back of your chair and additional side speakers to play stereo vinyl.

If you playing 2 channel stereo via home theater 7.1 setup then i don’t know what you’re actually listening to, but definitely not what is on the record (mixed and mastered for 2 channel stereo in the studio). The sound/mastering angineer has just Left + Right monitors in front of him. 

When you decodes 2 channel to 7.1 how come it can be better than just Left + Right if the recordning was made for Stereo?

I remember all this stuff, but doubt I ever even heard a CD-4 record back in the day set up on a system to properly decode it; the SQ and QS formats had more market penetration, at least where I was in the NE in the early ’70s, but even those faded pretty quickly-
I gather there are people who like the effect of some of the matrixed (not discrete) mixes for two channel playback, never really bothered, though every once in a while an old record will come across my path where it is claimed to be ’quad mix’ (presumably SQ).
And in addition to the Shibata, CD-4 is what got us that lovely JVC vinyl compound for a while. 

The demodulators are for the CD-4 LPs.

i used to have a 4 chanell setup back in the early 70's. cd-4 had the best separation. but you needed a cartridge to pick up signals up to like 40.000 hertz with a unit called a 'demodulater' i notice that today many cartridges can go up to 40,000 hertz. i don't know if any demodulaters are available today but that's how it was back then.

Ok but a proper decoder is what ...?

@tatyana69 see the link below:

https://www.ebay.com/itm/Vintage-Sony-SQD-2070-SQ-Decoder-Tested-Works-Great/292327234714?hash=item4...

tatyana69

Ok but a proper decoder is what ...?

You'd need a decoder designed for the format you’re trying to decode, such as a JVC CD-4-50 for the CD-4 format. Or something like a Sansui QSD-1 for QS-encoded LPs.

Ok but  a proper decoder is what ...?

akg_ca

You need a proper real Quad receiver, whether is was SQ formate or the synthesized stereo-based format QS format.

This is mistaken. There’s no reason to confine yourself to a "quad receiver" to reproduce quad. You just need a proper decoder - these were available as outboard devices.

... or the synthesized stereo-based format QS format ...

QS quad was no more "synthesized" than SQ quad. It was four channels matrixed to a two-channel format.

You need a proper real Quad receiver, whether is was SQ formate  or the synthesized stereo-based format QS format. The discrete 4- channel was available on tape .... reel or 8-track.

I experienced it back in its heyday: The LP was a flash in the pan novelty bordering on a gimmick even back then, with limited appeal to users. It's audio reproduction was nothing to get excited about 

it it has some fad appeal in tape format but again a rapid flame-out.

i wouldn't bother chasing after it today- its not worth it IMzo,  other than very isolated nostalgia appeal .

http://www.obsoletemedia.org/sq-quadraphonic/

SQ Quadraphonic (from ‘Stereo Quadraphonic’) was a system for providing quadraphonic sound from four speakers on vinyl records. It was introduced by CBS Records in 1971, and was adopted by a number of other record companies including EMI and Sony.

It was a matrix format, so the four channels were encoded into the stereo grooves of a 12-inch LP and then decoded back to four channels. As the grooves were slightly broader than a standard LP, playing time on an SQ record was reduced.

Of the different quadraphonic systems for vinyl, SQ has the largest discography and this was partly because SQ records were fully compatible with stereo equipment. Some early Compact Discs still used the SQ mix.

Consumers needed to buy an SQ decoder to take advantage of quadraphonic sound, but early versions provided poor separation. The sound separation of the SQ system was greatly improved by the introduction of SQ Full Logic decoding in 1975, but by this time all quadraphonic systems were declining in popularity and by the end of the 1970s, virtually no SQ Quadraphonic LPs were being released.

So the quadraphonic lps need a special cartridge ... and phonostage then. So presumably playing with a normal cartridge and phonostage some channels are missing, hence maybe a weaker sound for a number of reasons, presumably, from what you are saying?
Must be for a very limited market place these records then

I feel I am either being stupid or missing something here
If the Bryston decodes elements into separate aspects to surround speakers I was wondering if the input already into 4 may provide an easier or more varied decoding

You are missing something- the history.
4-channel was a thing that showed up in the 1970s. It was very much a precursor to surround sound and home theatre.

There were several formats- several forms of 4 channel tape, 4 channel encoding on FM stereo (usually SQ) and three competing formats on LPs.

The three LP formats were CD-4, SQ and QS. All are compatible with 2 channel playback. A decoder was required to extract the 4 channel information. In the case of CD-4, the rear channels were encoded on an FM carrier track that was outside of the audio band (and so needed a special cartridge, although many modern cartridges have the bandwidth and stylus that can do the job). The special cartridge saw the introduction of the Shibata stylus.

QS was the Sansui encoding, and SQ (if memory serves) was Columbia. They used phase information encoded in the grooves to extract the rear channel information.  Because of the method of phase encoding, its not surprising to hear that they don't sound as 'strong'.

All of these systems are analog based. If I understand correctly, the Bryston is not- so it can't decode these LPs. You'll have to look out for the decoders on ebay- they are easy to find and not expensive.

So is any quad beneficial element picked up in a normal cartridge and phonostage, or just "wasted"?
From what you are saying all elements are in principle "recovered"?
I feel I am either being stupid or missing something here
If the Bryston decodes elements into separate aspects to surround speakers I was wondering if the input already into 4 may provide an easier or more varied decoding

tatyana69

So the quadraphonic lps need a special cartridge ... and phonostage then. So presumably playing with a normal cartridge and phonostage some channels are missing, hence maybe a weaker sound for a number of reasons, presumably, from what you are saying?

No, all of the quad LP formats were compatible with two channel playback, at least as far as I can recall.

I am looking at Ebay uk an item called
CARLY SIMON ~ HOTCAKES ~ USA QUADRAPHONIC STEREO AUDIOPHILE LP
So the "stereo" word is out of place, or indeed wrong?

No, it's not wrong at all. Quadraphonic is a type of "stereo," just as two channel is a type of stereo. "Stereo" is not confined to two channels.

I am looking at Ebay uk an item called
CARLY SIMON ~ HOTCAKES ~ USA QUADRAPHONIC STEREO AUDIOPHILE LP
So the "stereo" word is out of place, or indeed wrong?

The Bryston very successfully codes 2 channel into 7.1.
I never play analogue into stereo 
So the quadraphonic lps need a special cartridge ... and phonostage then. So presumably playing with a normal cartridge and phonostage some channels are missing, hence maybe a weaker sound for a number of reasons, presumably, from what you are saying?
Must be for a very limited market place these records then

chakster

Quadraphonic Records (Descrete-4 or CD-4) require special cartridge and special processor, also 4 speakers

CD-4 was only one of the quad LP formats, although I think it may have been the only discrete format for LP.  SQ and QS were competing formats to put quadraphonic audio on LP.

@tatyana69 

You Bryston has nothing to do with Quadraphonic Descrete-4 records. In fact your Bryston designed for Digital Audio (Dolby Surround) in Home Theater application. 

To play records you need just normal stereo (Left and Right channel). 

Quadraphonic Records (Descrete-4 or CD-4) require special cartridge and special processor, also 4 speakers. You can learn more about it here https://en.wikipedia.org/wiki/Compatible_Discrete_4   

tatyana69

If normal analogue comes through as 2 channel, what effect does a quadraphonic record have?

It isn’t clear what you mean by "normal analog." Analog can be any number of channels. Two-channel stereo is just one configuration.

In any event, a quadraphonic record can store four channels, which you can feed to a quadraphonic system using a proper phono cartridge and phono preamplifier.