fec Posted July 29, 2003 Share Posted July 29, 2003 Hi - I was just given (for a quarter apiece) a huge collection of records. Some of them are quad. I'd like to buy a quad decoder, receiver, or anything that would allow me to fool around with these quead records. Don't know too much about this, so I don't want necessarily to spend a bunch of money. Thanks - Forrest 1 Quote Link to comment Share on other sites More sharing options...
lynnm Posted July 29, 2003 Share Posted July 29, 2003 A Dynaco QD-1 (original or more recent version can typically be found for under $50.00 and is an excellent way to experiment cheaply). Quote Link to comment Share on other sites More sharing options...
HDBRbuilder Posted July 30, 2003 Share Posted July 30, 2003 First of all, you need to know what type of quad your records are encoded in. There were three types of quad-encoding used in those days: SQ matrix, QS matrix, and CD-4/Discrete. In order to play ANY quad album, you would need either a receiver that has all three of these formats BUILT INTO it, or you would need to aquire a quad amp or receiver and buy the separate outboard decoder or demodulator units to play these different format albums. In addition to this requirement, in order to play CD-4/Discrete albums, your turntable needs to be equipped with a CD-4/discrete cartridge/stylus...and these are hard to come by...this is not necessary for QS or SQ matrix albums, but IS NECESSARY for CD-4 to operate correctly! CD-4/Discrete was the ONLY TRUE 4 channel ever laid down on record albums...the other types were simply matrixes, which used a carrier signal to "tell" the decoder which signals from each channel were to be sent to the rear speakers. With CD-4/discrete, the rear channel signals were remodulated up to a higher bandwidth and then laid into the record tracks...this bandwidth is above the human range of hearing (IOW, whereas the left and right front signals are approximately 20-20,000 Hz, the rear channels are on the record grooves as around 25,000-45,000 Hz). In order to recover these left and right rear signals, they have to be run through a turntable cartridge that can effectively pick up these higher frequencies, then they have to be run through a CD-4 demodulator which will remodulate them down to their original bandwidth, and send them to the rear channels. As for buying a receiver that can do all of this...my favorites are the Harman/Kardon 800+ and 900+ models...everything is built into them. All you need is a turntable and cartridge capable of CD-4 and you are all set to crank up the lava lamp, hang up the black light posters, and hear Jethro Tull's "Aqualung" album as you have never heard it before!! Quote Link to comment Share on other sites More sharing options...
Gregorius Posted July 30, 2003 Share Posted July 30, 2003 Andy, Nice to hear from you, how have you been? I bought a Pioneer QX-949 Quad receiver at Goodwill for $14, and it works great. I don't have anything encoded in Quad so I really haven't used it except for 2-channel. I think it has all of the matrix's inside. It is a heavy receiver, about 40+ pounds, I think it cost $750 back in 1975. Regards, Greg Quote Link to comment Share on other sites More sharing options...
lynnm Posted July 30, 2003 Share Posted July 30, 2003 Andy is correct regarding the accurate decoding of "Quad" signals....but trust me the Dynaquad does a decent job. To test the Dynaquad concept - assuming you have an extra pair of speakers that are similar in efficiency to your mains. Wire the front speakers as per normal The rears will need a little weirdness in their hook up. Connect the (-) terminals of the speakers together . Run a line from Left (+) on the amp to Left (+) on the Left Rear speaker. Run a line from Right (+) on the amp to Right (+) on the Right Rear speaker. Do not make any connection to the (-) terminals on the amp. In any event the (-) circuit has already been completed via the normal Front mains connection. (Optional but worthwhile) Wire a 10-50 watt wirewound resistor with a value of about 10 ohms in one of the lines. The resistance value so long as it is kept low is far less important than that it be a wirewound type. A non-wirewound resistor will merely reduce the signal strength without introducing a delay into the signal path. The same effect can be achieved using an inductor but I do not have the foggiest notion of the reactance value in Mh would need to be. Quote Link to comment Share on other sites More sharing options...
fec Posted July 31, 2003 Author Share Posted July 31, 2003 I appreciate the info so far... I do have a Dynaco qd-2 and I am amazed at what the addition of the center channel does for my albums. I rarely hear much from the rear speakers, but I suspect it may be that they are not efficient (like the Fortesand heresy in front). Iv'e never had or been exposed to quad. Eliminate cd-4 from the mix, since i have not and probably won't ever spend the money for a cartridge to play those. I guess my specific questions are: 1) When playing qs for example, are there four equal channels, or is more like surround sound where the back channels provide "fill" or "ambience"? 2)Does the QD-2 do the same thing as a quad decoder ( like sansui for example) from the old days? 3) If I did have more efficient speakers in the back, would I get the same thing or something close to what an old qaud receiver or amp would have done? Or to get the full effect do you need the decoder and 4 channel amplification? Thanks for your patience - - 1 Quote Link to comment Share on other sites More sharing options...
garymd Posted July 31, 2003 Share Posted July 31, 2003 Just saw this on ebay. Kenwood quad receiver item #3038068058. The reason I was looking was because my local pennysaver had an add for a KR-9600 like the one I've owned since the late 70s. Great SS receiver and I was hoping to get it cheap. I'm taking a look tomorrow. Kenwood made good stuff in the 70s and that quad may be what you're looking for. It's currently at $60. Good luck with your search but as I think Lynnm said, make sure it's compatible with your new albums. Quote Link to comment Share on other sites More sharing options...
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