Sansui introduced the QS quad encode/decode system in February 1972. Similar to SQ and EV-4, QS can decode any matrix-type quad encoded record along with synthesizing quad from a stereo source. Often, QS is shown on quad equipment with the designation “RM.” This stands for Regular Matrix. Supposedly, RM is the QS type without logic in the decoder.
I think Sansui’s grooviest invention was the famous Vario-Matrix circuitry. Various audio magazines described this circuitry in a most confusing manner. Some described Vario-Matrix as a “logic circuit” that improves channel separation. Another writer said it was specifically designed to synthesize a stereo source into a quadraphonic output. Whatever it was intended to do, it sure does sound good. Almost everything I play; FM, Compact Discs, records, whether it’s a quad or stereo version, is passed through my Vario-Matrix circuitry. Stereo sounds dull, lifeless, and boring compared to the sound of my quad receiver pumping out the tunes through its Vario-Matrix decoder.
This is the “odd man out” in the quad world. Extremely ‘fine’ grooves were etched onto the vinyl record to provide frequencies between 35,000 and 50,000 hertz. The CD-4 demodulator sensed these high frequencies then converted them to a range of around 100 to 15,000 hertz. These frequencies were then sent to the amplifier and on to the rear channels.
A matrix decoder can not sense the high frequencies on a CD-4 record, it can only synthesize the stereo output of a CD-4 QuadraDisc LP.
My own experience with CD-4 led me to stick with matrix-type quads. To hear a quad sound from CD-4 encoded vinyl I just send it through my Vario-Matrix decoder and let it synthesize a quad sound. However, there ARE those who use and enjoy CD-4. Cai Campbell is a quad expert with an opposing view. Here is his opinion:
There’s three, yes, count ’em, three ways to provide a quad source to your super-duper quad hardware; reel-to-reel tape, 8-track tape, and vinyl record. Okay, you can use cassettes, etc that have quad recorded on them, but, I’m talking about original sources here.
Of the three formats, reel-to-reel tape is the rarest and it’s the most expensive to buy today. 8-tracks can be the cheapest if you find them locally at garage sales, thrift stores and used record/tape stores. I’ve bought quite a few quad 8-tracks for 10 to 50 cents each. Whadda’ deal!!! If you buy quad 8-tracks at Internet auction sites, be ready to pay top dollar. Records are the most commonly found quad software. Prices can vary greatly. Stuff that’s still-sealed gets the highest prices. For example, my still-sealed CD-4 Muscle of Love by Alice Cooper sold for 30 American dollars. Some quad records are readily available. The Doors Greatest Hits is a common one. There are oodles and gobs of ’em out there. Others are harder to find. I hunted all over before finding my groovy Nashville Skyline by Bob Dylan.
Audionics Shadow Vector Analysis Unit. $1,300 in 1976. SQ with logic gave 35db channel separation.
Bang & Olufsen Beogram 4002 turntable with plug-in demodulator
Bose 4401 preamp optional SQ & CD-4 plug-in modules. 1974 $500. $75 for the SQ module.
Connaught Equipment Co. supposedly built a SQ decoder with 40db separation in 1974
Super SQ Model One by the Deltek Co. $2,150 in 1977. Stereo Review in its Apr ’77 issue called it the ultimate in SQ decoding
Heathkit; anything by these folks. They provided the parts and instructions. You slapped it together.
Integrex Ltd. Built a decoder up to 1981 that handled SQ, QS, UMX, Matrix H/HJ/UHJ.
Scott 499 amplifier. Supposed to be the first specific “quad component” other than a tape deck to hit the consumer market.
Sansui QSD-1 one of the ‘super decoders’
Any jukebox with built-in decoders. Wurlitzer is supposed to have built a few.
There was a list of rare and hard-to-find vinyl LP’s here, but, they have been removed. The Wild Wooly Wide Web of the World now allows the masses to communicate in many ways, one being the ability to offer quad goodies for sale and trade. The eBay auction site is a nifty place to find what were once rare quad records and hardware. It may take awhile for that rare goody to show up there, but, with patience, pert near anything quad you lust after will show up eventually..
Quad 8-Tracks Q8
A reader wondered as to the best method of identifying a quadraphonic 8-track tape. The easiest method for me is the back label pasted on the cartridge. Only two “sides” of songs are listed instead of the stereo 8-track’s 4 “sides”.
There is also a slot in the cartridge to “inform” the tape player that the 8-track is a quad tape. I sold all my 8-track tapes so am unable to take a picture to show you but some Web searching may lead to a picture.
My memory hints to me that there is another identification method but I am unsure and I doubt my aging brain with rusty synapses will reach way back into those dusty recesses of a once sub-par mind that is now sub-sub-sub-par.
Old age sucks.
***End of Update***
Quad 8-tracks had the same limitations the stereo versions had. The worst being the tendency to be “eaten.” Gulp. Remember those glorious days of cruising down the road and seeing the tangled mess of tape blowing in the breeze? There goes another dead 8-track.
Still More Stuff
Like, outtasight !!! Back in the groovy sixties and seventies, until forced to conform by standards imposed by the US federal government, many audio manufacturers used various methods to rate the power output of their equipment. Today, “watts RMS” per channel is the de facto standard. It’s a handy figure for comparing between audio offerings. Waaaay back when, however, one must take the output ratings of audio equipment with the proverbial ‘grain of salt.’ Some equipment builders used “IHF” power ratings, which give higher ratings than RMS power output figures.
Just sumpthin’ to keep in mind when viewing old advertisements of quad components.