For some basic info try this site:
www.geocities.com/quadaudio/
eBay auction site is a handy place to buy stuff but you takes yer' chances. In larger cities with stores offering used audio gear one can often find used quad stuff and can check it out before buying.
One can go the "modern route" and use the latest technology. I haven't kept up with the new stuff but there are some pros here that do.
Budget constraints affect some. I watch eBay and go for the good deals. I bid X amount and stop. I lose 98% of the time. Once in awhile I get lucky. I've even had folks e-mail me offering to buy what I have won.
I gotta' stand-alone decoder, a Sony SQA-2030, in excellent condition cheap. I was offered twice what I paid for it!!!!! Perseverance furthers!!!!
Since the old stuff is just that, old, there is something to be said for buying the newest stuff if it's affordable. Some folks like the retro thrill of using the old stuff.
Also, one has to consider their goals. After several years of messing around I decided to basically pursue the conversion of stereo to a surround sound using various decoders to synthesize the quad effect. The advent of CD's helped me to arrive at this decision since my decoders slurp up a CD's stereo output and do a wondrous job of creating a synthesized surround sound field... much better then when the source is from a vinyl recod, tape, FM radio, etc.
Some folks demand a surround sound from encoded sources. THat's fine. I, too, have my collection of encoded source material. However, the ability to synthesize surround is my prime motivator. One reason I like my Vario-Matrix so much. That, and my recently acquired Circle Surround decoder whose output is fed into the Vario-Matrix in my QRX-9001. I love the audio output. I won't declare it will match the good stuff the other guys have but, for my budget and listening tastes I'm thrilled.
Depending upon your aural desires, lusts, longings, etc. you have to determine what route to use. A basic system using the quad or surround sound synthesizing approach will be much cheaper than a dedicated system aimed at decoding encoded material.
You could start small and work your way up. For basic amplification there is always the "double stereo" route. Name brand basic stereo receivers are dirt cheap, especially when on sale. I recently bought a Technics 100 watt per channel stereo new for $100. Sounds just fine to me. With two of them you have you 4-channels of amplification. Add a decoder and you're on your way!!!
Not all decoders are created equal. But, any decoder is better than none at all. Later name brand decoders made from 1974 onwards tend to have various forms of logic that improve the surround sound. Some adore the Sansui Vario-Matrix system while others with the bux go after the Tate decoder. Lafayette also made some good decoders as well a Sony.
Check out Tab's site for a neato peek at how some decoders operate. And, if you see one for sale ask what others think about its abiltity to decode.
Okay. Yhat's enuff from me. There are various routes you can take and none are right or wrong, they're just different. No matter which path you trod you will likely think as I do... after any style of surround sound, new or old, basic or fancy/expensive, plain old boring stereo is just that... boring!!!
