Quadraphonic: How to

Almost1

Almost1

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Alright guys, please excuse my ignorance, but I am having trouble wrapping my head around this.

How do media devices achieve quad channel operation through a stereo input? I'd love to take advantage of my 2000 or 4000's abilities even if it doesn't end up being a long term setup.
 
Don't think that can ever be achieved.....but what do I know.

Need a quad amp & media to fulfill???
 
From what I've been reading, the media is encoded and then decoded in the pre-amp (similar to AM or FM radio) before being sent out. That being said, I see that most people talk about LP when talking about quadraphonics, but that can't be the only format. Does the demodulation happen over all of the inputs or just phono?
 
Other older quadraphonic formats include 8-track tape and open-reel tape. Some older quadraphonic receivers could simulate quadraphonic sound from a stereo signal. And don't forget modern digital sources recorded in 4.1 surround parallels quad.

Nando.
 
The earliest attempts to reproduce four channel sound began with audio laboratory engineers in the 1960s. The most popular medium used to market recordings to the public during the 1970s was the vinyl LP phonograph record which is an analog recording source. As technologies advanced rapidly during the 1970s many different solutions were proposed to reproduce 4 channel sound from LPs. The simplest systems were "derived" (2-2-4) formats. These were soon followed by more sophisticated "matrix" (4-2-4) formats, and finally, by the most advanced "discrete" (4-4-4) formats.

All of the systems in common use today are discreet formats and are digital recording systems. Digital multichannel audio has been available for the home starting with the introduction of Dolby Digital and DTS in the 1990s. The most common digital media capable of reproducing 4 or more sound channels today are Super Audio CD, DVD, and Blu-ray.

From the Wiki...
 
I'm slowly but surely beginning to understand what's happening. Do I need to coordinate the (2-2-4), (4-2-4), etc. media with the pre-amp? Which formats do our PL's decode? Does this happen over all of the inputs?

It makes me wonder if I can find a digital copy of older quadraphonic music and still have the PL decode it. As long as the carrier signal is retained, of course.

Edit: It looks like only the 4000 I was capable of decoding SQ. 2000 II only had an ambiance circuit, and the 4000 II just had A and B outputs. Oh well, maybe I'll get to quadraphonic one day...

What's the consensus on ambiance on the 2000? Worth testing out on 4 speakers?
 
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PL 4000 ( 2nd version only ) is able to decode to SQ records and performs a sort of ambience .
For amusement I tested these functions with 2 small speakers ( AR 8bx ) and Yamaha 2010
as power amp ( both already owned ) . Unbilievable , it works .
So I bought this little class t power amp
https://www.amazon.it/gp/product/B008Y7S198/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
Thereafter everything is O.K.
Front speakers are Allison One powered by a PL 700 B .
Ciao
Marco
 
marcok said:
PL 4000 ( 2nd version only ) is able to decode to SQ records and performs a sort of ambience .
For amusement I tested these functions with 2 small speakers ( AR 8bx ) and Yamaha 2010
as power amp ( both already owned ) . Unbilievable , it works .
So I bought this little class t power amp
https://www.amazon.it/gp/product/B008Y7S198/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
Thereafter everything is O.K.
Front speakers are Allison One powered by a PL 700 B .
Ciao
Marco
Click to expand...
Ah, I see! Looked up a couple pics of the series 1, and wouldn't you know it, one explicitly states 4 channel SQ + Logic, and the other ambience.
 
If my memory serves me PL 2000 ambience function works both with 2 and 4 channels .
Test and test again , using spare amp and speakers ( if you have ) .
This system probably is the forefather of Carver' s Hologram.

Ciao
Marco
 
marcok said:
If my memory serves me PL 2000 ambience function works both with 2 and 4 channels .
Test and test again , using spare amp and speakers ( if you have ) .
This system probably is the forefather of Carver' s Hologram.

Ciao
Marco
Click to expand...
Yeah, PL2000 ambience works in 2 channel mode. Never tried it in 4 channel. Manual says amount of ambience depends on source material. Don't think it's anything like true quadraphonic. Check out those monster Marantz Quad receivers that had the decoder cards and CRT display. Don't think PL ever had anything like that, not even close. Think Pioneer also had the big Quad receivers.
 
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In the New Year, I'm putting my Sansui QR-4500 quad receiver up for consignment sale at Innovative Audio. I've owned it for about 13 years and I already have a couple of other nice vintage quad receivers.





It's a beaut. I bought it for $30 back in 2007 and it came into the local mini flea market with a pair of Pioneer CS-66e speakers and a pair of Sansui SP-2000 speakers.

Lee has one of these, too - Pioneer RT-2044 quad open-reel recorder. I use it, coupled to my Pioneer QX-949 receiver.



Nando.
 
George S. said:
Yeah, PL2000 ambience works in 2 channel mode. Never tried it in 4 channel. Manual says amount of ambience depends on source material. Don't think it's anything like true quadraphonic...
Click to expand...

This sounds a lot like Dynaco's "Dynaquad" ambience recovery trick which, IIRC, is done by essentially reversing polarity on the two rear speakers? (That's probably an extreme over simplification.) In 1975, I built an SCA-80Q, the "quad" version of their 40 wpc SCA-80, which had connections for four speakers. They also made a stand-alone box that performed the same ambience recovery function as the circuitry in the integrated amp I had. The "quad" ambience recovery effect was very much source-dependent. Live and classical albums generally did better with the amount of hall ambience in the recording.
 
Bob Boyer said:
This sounds a lot like Dynaco's "Dynaquad" ambience recovery trick which, IIRC, is done by essentially reversing polarity on the two rear speakers? (That's probably an extreme over simplification.) In 1975, I built an SCA-80Q, the "quad" version of their 40 wpc SCA-80, which had connections for four speakers. They also made a stand-alone box that performed the same ambience recovery function as the circuitry in the integrated amp I had. The "quad" ambience recovery effect was very much source-dependent. Live and classical albums generally did better with the amount of hall ambience in the recording.
Click to expand...
Your most probably correct. The PL2000 has RCA jack connections for "front" and "rear" outputs on the rear of the unit. The "Ambience" has a push button on or off with a pot to control the effect. To me, it's just a gimmick. Never looked at the schematic to see how it works. I keep it bypassed along with the tone control pots.
 
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