Quadraphonic records (LPs to you and me)

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.

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

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.

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

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.