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rca quadradisc dynaflex vinyl, what category of quad vinyl?

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Doug G.

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Neither, They are their own category. As I suggested in the other thread, read up about the difference between matrix and discrete. They are not really related except for both being quad systems.

Doug
 

fredblue

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RCA QuadraDiscs (and the handful of Dynaflex QuadraDisc releases) are for the CD-4 Quadraphonic system.

for CD-4 to work properly you will need a CD-4 disc demodulator unit and a phono cartridge with a Shibata or similar profile stylus that can resolve the high frequency response required.

some phono cartridge manufacturers used different names to describe the Shibata type stylus, including Audio Technica's "MicroLine".

all aspects of turntable setup, i have found, are crucial to getting good CD-4 Quadraphonic sound.

then the discs need to be in good shape, very clean, etc.

if you have time on your hands (and patience) go for it, it can be fun and frustrating in equal measure but it is worth it.

if you want plug and play Quad, i would say SQ and especially QS are easier formats to setup.

check in with us here anytime and we will try our best to help you for sure 🙂
 

Doug G.

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Oh, and "Dynaflex" has nothing to do with quad. It's the name for discs RCA originally released in the early seventies which are very thin and flexible. They claimed Dynaflex discs actually warped less than thicker discs. Whether they did/do or not had been a source of debate since they debuted.

One factor is they probably were trying to conserve material when petroleum-based products became more scarce although the development, in the late sixties, actually predated that whole era (about 1973-74).

I have never had any problem with Dynaflex discs simply because they were Dynaflex. I do remember getting a disc having a non-fill issue but that wasn't due to it being a Dynaflex. Any pressed disc can have that happen in the press. With this particular one, (David Bowie "ALADDIN SANE), the non-fill was at the very outer edge so I kept it.

However, the whole controversy caused RCA (and other record makers, who followed suit) to abandon Dynaflex toward the late seventies.

Doug
 

aifrecords

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RCA QuadraDiscs (and the handful of Dynaflex QuadraDisc releases) are for the CD-4 Quadraphonic system.

for CD-4 to work properly you will need a CD-4 disc demodulator unit and a phono cartridge with a Shibata or similar profile stylus that can resolve the high frequency response required.

some phono cartridge manufacturers used different names to describe the Shibata type stylus, including Audio Technica's "MicroLine".

all aspects of turntable setup, i have found, are crucial to getting good CD-4 Quadraphonic sound.

then the discs need to be in good shape, very clean, etc.

if you have time on your hands (and patience) go for it, it can be fun and frustrating in equal measure but it is worth it.

if you want plug and play Quad, i would say SQ and especially QS are easier formats to setup.

check in with us here anytime and we will try our best to help you for sure 🙂
thank you fred, I am trying to find a diagram or answer to how do u hook up a regular 4 channel stereo receiver to one of these old demodulators? every in goes to out and vice versa i know, so would i go from outs of demodulator to tape ins/play of say tape one or two in the back of my stereo amp? then just plug turntable into phono holes on back of my stereo amp like I always do? the google diagrams are for people with engineering degrees and dont specifically address quad set up and cd-4 needs.
 

fredblue

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thank you fred, I am trying to find a diagram or answer to how do u hook up a regular 4 channel stereo receiver to one of these old demodulators? every in goes to out and vice versa i know, so would i go from outs of demodulator to tape ins/play of say tape one or two in the back of my stereo amp? then just plug turntable into phono holes on back of my stereo amp like I always do? the google diagrams are for people with engineering degrees and dont specifically address quad set up and cd-4 needs.
you're welcome 🙂

with CD-4 you want the most direct, shortest signal path from turntable to demodulator.

so first you need to connect the 2-channel phono output from the turntable directly into the demodulator phono input.

then you should find the CD-4 demodulator has 2 x sets of outputs;

1.) a 2-channel "direct output" of the turntable's original input signal, which relays the signal back out to a preamp.
this amplified signal is then daisy-chained into another Quad system decoder, for SQ or QS LPs,

2.) a 4-channel output of demodulated Quad, comprising Front Left Out, Front Right Out, Rear Left Out and Rear Right Out.

you then connect these 4 x outputs to the corresponding Front Left In, Front Right In, Rear Left In and Rear Right In on the Receiver.
 

Doug G.

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I have never used the direct output of a demodulator or connected the turntable to the phono inputs on an amplifier/receiver with which I am using an external demodulator. I let the demosulator switch between CD-4 and stereo automatically and it has always worked. That way, you get output from all speakers which is far more satisfying, in my opinion.

Matrix decoders can then be connected as usual into the tape monitor loop.

Doug
 

Cyber 1

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Oh, and "Dynaflex" has nothing to do with quad. It's the name for discs RCA originally released in the early seventies which are very thin and flexible. They claimed Dynaflex discs actually warped less than thicker discs. Whether they did/do or not had been a source of debate since they debuted.
Doug
ya but what else were they going to say to pawn off recycled :poop:, better just avoid those orange labeled mistakes from the past, at least for the North American pressings.
 

Doug G.

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As I said, I have never had any problems with Dynaflex discs. The "recycled" bit is way overstated if not false.

Doug
 

Wagonmaster_91

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thank you fred, I am trying to find a diagram or answer to how do u hook up a regular 4 channel stereo receiver to one of these old demodulators? every in goes to out and vice versa i know, so would i go from outs of demodulator to tape ins/play of say tape one or two in the back of my stereo amp? then just plug turntable into phono holes on back of my stereo amp like I always do? the google diagrams are for people with engineering degrees and dont specifically address quad set up and cd-4 needs.
The short answer is: Plug your turntable into the CD-4 demodulator Phono inputs. Plug the CD-4 demodulator outputs into the "Discrete" inputs on your quadraphonic amp.
 

fredblue

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I have never used the direct output of a demodulator or connected the turntable to the phono inputs on an amplifier/receiver with which I am using an external demodulator. I let the demosulator switch between CD-4 and stereo automatically and it has always worked. That way, you get output from all speakers which is far more satisfying, in my opinion.

Matrix decoders can then be connected as usual into the tape monitor loop.

Doug
there's more than one way to skin the rabbit for sure :)
i prefer to take the direct output and use an external phono preamp for 'non-CD-4' records as my Pro-Ject preamp has adjustable capacitance, impedance, gain, etc., which is useful depending on which cart i'm using for SQ, QS, etc.
 

J. PUPSTER

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there's more than one way to skin the rabbit for sure :)
i prefer to take the direct output and use an external phono preamp for 'non-CD-4' records as my Pro-Ject preamp has adjustable capacitance, impedance, gain, etc., which is useful depending on which cart i'm using for SQ, QS, etc.
🧐 Hmmmm...
 

Doug G.

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there's more than one way to skin the rabbit for sure :)
i prefer to take the direct output and use an external phono preamp for 'non-CD-4' records as my Pro-Ject preamp has adjustable capacitance, impedance, gain, etc., which is useful depending on which cart i'm using for SQ, QS, etc.
Of course but, no matter how you decide to skin the rabbit, the rabbit ain't gonna like it. :D

Anyway, what I wrote above applies only when I have my simplified setup, using only one turntable/cartridge. I used to have a more complex arrangement with one table dedicated to CD-4 and the other for everything else. The matrix decoder and demodulator were switched in separately and I was able to do it because the Heathkit AA-29 amplifiers I was using have two aux. inputs which adds a lot of flexibility.

I intend to eventually go back to that setup because it eliminates having to switch cartridges if I don't want to use a CD-4 cartridge on anything but CD-4 records, to preserve the stylus. As it is now, I switch back and forth on the same table which, even though it isn't a huge deal, I would rather not have to do it.

Here is what it looked like set up as I described:

P1030397.JPG


Doug
 

Sonik Wiz

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Of course but, no matter how you decide to skin the rabbit, the rabbit ain't gonna like it. :D

Anyway, what I wrote above applies only when I have my simplified setup, using only one turntable/cartridge. I used to have a more complex arrangement with one table dedicated to CD-4 and the other for everything else. The matrix decoder and demodulator were switched in separately and I was able to do it because the Heathkit AA-29 amplifiers I was using have two aux. inputs which adds a lot of flexibility.

I intend to eventually go back to that setup because it eliminates having to switch cartridges if I don't want to use a CD-4 cartridge on anything but CD-4 records, to preserve the stylus. As it is now, I switch back and forth on the same table which, even though it isn't a huge deal, I would rather not have to do it.

Here is what it looked like set up as I described:

View attachment 61688

Doug
Nice, clean organized set up. As you state there are decent reasons for having multiple TT's. Myself, I've always only had one. But the 80's an older quad friend had 3: one was a beast with idler wheel drive and good torque for cleaning with a Disc Washer. Then a TEAC table with CD-4 cart. I forget what his other TT was but it was unique in that it used a $$$ MC cartridge.
 

Doug G.

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Thanks. I'm glad I made a wiring diagram for the setup as I wouldn't want to figure it all out again. I could but I wouldn't want to.

Actually, I guess I had three tables, too. The Dual 1019 there was for playing 78's. It is currently at my son's as he played an old 78 into his computer, made at Paramount Studios in the early forties of a song my great grandmother wrote. It became fairly scratched up from we kids playing it on various players and not handling it exactly carefully. He has been trying to remove the noise from it which has proved to be difficult, finding a threshold where the noise is removed but the music is left.

Doug
 

atrocity

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Actually, I guess I had three tables, too. The Dual 1019 there was for playing 78's. It is currently at my son's as he played an old 78 into his computer, made at Paramount Studios in the early forties of a song my great grandmother wrote. It became fairly scratched up from we kids playing it on various players and not handling it exactly carefully. He has been trying to remove the noise from it which has proved to be difficult, finding a threshold where the noise is removed but the music is left.
I recently digitized a Dinah Shore 78 that had been left on a heavy-tracking wind-up acoustic player for some time and was apparently used as a demo by the late owners.

The initial capture sounded terrible, but I was surprised that DeNoise was able to do a reasonable job with it. Unlike ClickRepair, I find that I generally don't like the artifacts DeNoise can leave behind (definitely possible that it's user error!) but in this case it worked great.

Now if the author would just re-open the store. It's been unavailable for long enough now that I have a bad feeling about it:
 

atrocity

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Now if the author would just re-open the store. It's been unavailable for long enough now that I have a bad feeling about it:
Oh, this is not good at all:

'I emailed and received a response from Brian Davies, the developer of ClickRepair. Brian indicated that "I am too ill to continue and don’t expect to recover..."'
 

fredblue

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going through the old Quad LPs, one that isn't specifically called "Dynaflex" but the vinyl is so alarmingly thin and floppy it might as well be, is Hugo Montenegro's "Rocket Man", a 1975 RCA release.. however it sounds great and demodulates like a champ, so i guess its not all about the thickness or stiffness of your disc where CD-4's concerned 👍 :LB
 
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