Quadraphonic L P played with a 2 chan. cart.

Eldarford, I believe the quad LP system, which uses a FM signal, to which you refer, was the JVC CD-4. It was arguably better than the SQ & QS systems, but at least, as you said, it improved the high frequency tracking of cartridges to this day.

Inpepinnovations...I also used a Lafayette SQ-L decoder, which is now in my collection of defunct audio stuff. It was probably the best of all the logic decoders. Mine is all discrete components and must have cost much more to build than the $99 I paid for it when it was discontinued. My guess is that the circuit was a prototype that they intended to implement in ICs. I modified it a bit and used it as my preamp for several years. It had a bit of gain which made this practical.

To all that responded or interacted to my initial inquirey:

Thanks; I am always amazed at the level of knowledge and interaction amongst the members here on Audiogon. Although, I am relatively new as an audiogon member and a novice to the level of information on the subject of audio equipment and its theory which the body of menbers have attained; I hold myself out as a 70's student who is willing to learn.

Thanks,

Bruce