Neophyte in desperate need of quad hardware setup help

I have been searching the forums to answer this question but have not found an answer.

I've been a lover of CD4 discrete quad since I bought my first receiver in 1975 which was promptly stolen from my apartment. I've been on a quest to build a rudimentary system over the years. I have a Pioneer SX-1250, QA-800A and Technics SL-1400 turn table. having recently moved, I have not been able to couple these units together. I am totally lost and in desperate need of help. Does anyone have suggestions for a qualified Quad person to hire in the Minneapolis/Saint Paul area to set the system up? All suggestions are greatly appreciated.

Mark

Mark Parsons said:

I have been searching the forums to answer this question but have not found an answer.

I've been a lover of CD4 discrete quad since I bought my first receiver in 1975 which was promptly stolen from my apartment. I've been on a quest to build a rudimentary system over the years. I have a Pioneer SX-1250, QA-800A and Technics SL-1400 turn table. having recently moved, I have not been able to couple these units together. I am totally lost and in desperate need of help. Does anyone have suggestions for a qualified Quad person to hire in the Minneapolis/Saint Paul area to set the system up? All suggestions are greatly appreciated.

Mark

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Well as long as your turntable is compatible (has the necessary sheilding cables), which it likely has, and you have a cartridge that reads the CD-4 carrier ? You should have no difficulty.



And I refer you to discs in CD-4 here https://www.quadraphonicquad.com/forums/forumdisplay.php?22-Discrete-LP-Formats-(CD-4-UD-4)


AND WELCOME

Looks like you have a stereo receiver, a quad amp and a turntable. I think you are missing a few important pieces.

1) Some sort of decoder/demodulator to playback the LPs that you may have
2) A quad tape deck, reel or Q8

Hooking it all up isn't that hard.

MikeP said:

Looks like you have a stereo receiver, a quad amp and a turntable. I think you are missing a few important pieces.

1) Some sort of decoder/demodulator to playback the LPs that you may have
2) A quad tape deck, reel or Q8

Hooking it all up isn't that hard.

Click to expand...

My issue is getting sound to all 4 speakers through the QA-800A.

As far as decoders, I have a Technics SH-400, Panasonic, JVC and Lafayette SQ decoders to select from. I only have discrete albums so the Lafayette is out. The turntable has an OM 40 stylus. The SX-1250 and QA-800A have been inspected and rebuilt as needed by a very experienced audio guy.

I just upgraded to an OM 30 stylus from an OM 20.

The OM 40 looks like it has the right specs (Nude Stylus= Shibata) and, although it states that it goes up to 30K, it will go up higher than that, trust me...

Nude does not equate to Shibata. There are nude Shibatas, but there are also nude ellipticals. Fine line, micro-ridge and hyperelliptical styli are also not Shibatas, although they are similar ... and frequency response alone is no guarantee of CD-4 compatibility. One thing you must consider is the separation spec at ultrasonic frequencies. The ability to play those frequencies is no guarantee that it will work properly. Nude just refers to the way that the stylus is mounted to the cantilever ... and any stylus shape can utilize nude mounting.

Mark, you could not be in a better place to be seeking out help, friend...you're right in the neighborhood of Jerry Raskin, "The Needle Doctor"!

When I was living there, his store was in Dinkytown, across from the comic store (which isn't in that location anymore, so why did I bother bringing it up). He may have gone online since, but he's out dere somewhere, by golly!

Don't make a move until you get in touch with him!

Quadzilla said:

Nude does not equate to Shibata. There are nude Shibatas, but there are also nude ellipticals. Fine line, micro-ridge and hyperelliptical styli are also not Shibatas, although they are similar ... and frequency response alone is no guarantee of CD-4 compatibility. One thing you must consider is the separation spec at ultrasonic frequencies. The ability to play those frequencies is no guarantee that it will work properly. Nude just refers to the way that the stylus is mounted to the cantilever ... and any stylus shape can utilize nude mounting.

Click to expand...

You are ABSOLUTELY RIGHT...I'd forgotten my "Shibata" table----they have a "triangular" shape...but I still think that the OM 40 would work...

kap'n krunch said:

You are ABSOLUTELY RIGHT...I'd forgotten my "Shibata" table----they have a "triangular" shape...but I still think that the OM 40 would work...

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Ortofon OM40 channel separation is 25dB @ 1kHz, and 15dB @ 15kHz. You will need to find the specs at 30kHz and 45kHz to determine its CD-4 suitability ... but based on the steep decline between 1kHz and 15kHz I suspect that it will not be. Excellent ultrasonic channel separation will make the difference between "hey, I can hear some stuff coming out of the rear speakers" and "holy crap, it's quadraphonic!".

Tonearm cable capacitance should also not be ignored. Modern turntables quite likely have low-capacitance cables already (>100pF over the length of the cable, and cable capacitance is measured per foot or meter of cable), but 30+ years ago it wasn't common at all. Even newer designs can benefit from PROPER low-capacitance cabling.

I use a Rega P3-24 turntable with an Audio Technica AT15Sa cartridge for CD-4 playback (not an antique TT by any means), and rewiring the stock RB-300 Rega tonearm with a low-capacitance Incognito wiring kit was my 'holy shit' moment in terms of Quadradisc playback. Capacitance is not as critical with low-output moving coil cartridges though, but the stylus is still an important consideration ... and you will still require a low-capacitance phono interconnect between the MC step-up device and your demodulator.

I know that some guys have mixed feelings about the CD-4 system, but very few of those guys are doing it right ... and that starts with an actual CD-4 cartridge, low-capacitance tonearm and interconnect wiring, and careful demodulator setup. Omit just one of those, and you will not hear what you are hoping for. Lou Dorren and Cai Campbell wrote a number of excellent posts on the subject. Sadly, both have left us.