CD-4 - The thin line between success and failure, but still in the fight!

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I fixed my PL-400 speed issue easily. Seems to be a similar technology. The caution is well-given.
Hopefully you won't need to, mine was an SL-1500 IINM, took it apart and did a re-lube on the main motor shaft, and Deoxite D5 on the various pots, but would never settle down. Did some more research and learned the main boards can go bad, and you're pretty much screwed at that point.
What did you do to fix yours?
 
Hopefully you won't need to, mine was an SL-1500 IINM, took it apart and did a re-lube on the main motor shaft, and Deoxite D5 on the various pots, but would never settle down. Did some more research and learned the main boards can go bad, and you're pretty much screwed at that point.
What did you do to fix yours?
Deoxit on the pots, fortunately.
 
Further testing on the 44D-10:
Stereo also dead when using the AUX out (not just the front L/R out) - maybe the switch went bad?
All's the hum kicks in when switching to CD-4 mode. Again, touching the TT's ground cable to the demod's ground peg makes the hum WORSE.
 
Do you recommend at cart/stylus?

Btw, do carts and stylus come in combos? Or do I need to track down both?

TIA!
I have been using the AT440MLB, chose it based on reading posts here. I was able to get two new for less than $190 each a few years ago, they are discontinued so prices for nos ones are bit higher now. The replacement VM540ML is also a bit more expensive than the 440ML.
 
Do you know of a Pioneer manual that does?
IIRC, one of the stereo equipment buyers guides listed the tonearm cable capacitance (haven't found the guide yet).

Seems logical that Pioneer would make their turntables CD-4 ready after 1973 when Pioneer introduced their quad receivers w/built in CD-4 demods.


Kirk Bayne
 
CD-4 advice is like asking how long is a piece of string? There's lots of answers. To make CD-4 work I am convinced that 90% is the cartridge and cables. If you are sure your table has low cap leads then the cart is the most important thing. I am running a Lyra Kleos moving coil cart. It aint cheap at about $5k but I love the smooth sound and it rocks CD-4. I have an old Marantz CD-400B and it works fine. Not great in terms of sound but the separation with this cart is super discrete. So if you are running an M24H, which I ran for many years you are missing out. The new gen of carts track so much better and makes those trashy sounding CD-4s clear!! Also, clean your CD-4s, but that is another thread...
Unfortunately, most of us can't drop 5 grand into a new cartridge, and have to use what we can afford.
 
Do you recommend at cart/stylus?

Btw, do carts and stylus come in combos? Or do I need to track down both?

TIA!
idk about that turntable, you know.. its probably upto the job but then you've only got so much adjustment and you need to be able to fiddle with everything to get CD-4 going ok. for example, there's no way to raise/lower the arm (so you can't adjust VTA, which is critical with an exotic stylus profile such as Shibata, Line Contact, etc.).

also, i'd think about picking up a 4DD-5 demodulator. they're cheap and plentiful and even though they're not fancy and don't have auto carrier lock they're still simple enough to get going and do the job as well as just about any unit, except 2-3 later HTF units (SH-400, 4DD-50) that are superior its the de facto standard really.

do you have a CD-4 adjustment disc with the 30kHz tone?

you'll want to get that 30kHz tone beeping or meeping if you can, a light squawk or a bit of breakup if the test disc isn't in the best shape is also ok. also you need to make sure you're playing back the difference signal with as little distortion as possible (you can hear this signal if you play a CD-4 record and turn down both separation pots to their bare minimum).

what cart/stylus are you using at the mo?
 
Forty seven years ago while still a member of uncle sam's yacht club I was overseas and shopping for a quad system at the Navy exchange and in 1975 I came away with a Pioneer PL-55DX that was made for CD-4 and that's what I use.I no longer use the PC-Q1 original cartridge and stylus but now have the AT331LP still seems to do the job but I admit I don't play albums much these days.
 

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Anyone know what I should ground the 4DD-10 to?
It creates a hell of a hum! Only has a 2-prong plug, so I'll have to pigtail a wire off its ground screw.
Thanks!

The string is twice as long as it is from the middle to one end.

I'd say after 50 years, the power supply capacitors are toast.
 
something i learned here that helped me with CD-4 is to use discs that have tracks with extreme discrete mixes and especially those with little to no lead vocals or lead instruments in the Rears (e.g. Spinners S/T, James Taylor "Gorilla", any of the Doobies, AWB, Sergio Mendes, Donny Hathaway) if you turn off the Front channels with these discs they're so handy for getting maximum separation in the Rears by turning those controls so the lead vocals/instruments disappear back there. if you have a copy of the Q8 or Q4 of one of these CD-4's even better because you can refer to the discrete tape version for exactly what should be in the Rears. ta-da! CD-4 magic! 😅🥳🤩
 
something i learned here that helped me with CD-4 is to use discs that have tracks with extreme discrete mixes and especially those with little to no lead vocals or lead instruments in the Rears (e.g. Spinners S/T, James Taylor "Gorilla", any of the Doobies, AWB, Sergio Mendes, Donny Hathaway) if you turn off the Front channels with these discs they're so handy for getting maximum separation in the Rears by turning those controls so the lead vocals/instruments disappear back there. if you have a copy of the Q8 or Q4 of one of these CD-4's even better because you can refer to the discrete tape version for exactly what should be in the Rears. ta-da! CD-4 magic! 😅🥳🤩
See, this is why I really need that new Involve Amp to materialize, with my QRX-8001 on the fritz also, I'm back to Quad re-build mode 😣
 
idk about that turntable, you know.. its probably upto the job but then you've only got so much adjustment and you need to be able to fiddle with everything to get CD-4 going ok. for example, there's no way to raise/lower the arm (so you can't adjust VTA, which is critical with an exotic stylus profile such as Shibata, Line Contact, etc.).

also, i'd think about picking up a 4DD-5 demodulator. they're cheap and plentiful and even though they're not fancy and don't have auto carrier lock they're still simple enough to get going and do the job as well as just about any unit, except 2-3 later HTF units (SH-400, 4DD-50) that are superior its the de facto standard really.

do you have a CD-4 adjustment disc with the 30kHz tone?

you'll want to get that 30kHz tone beeping or meeping if you can, a light squawk or a bit of breakup if the test disc isn't in the best shape is also ok. also you need to make sure you're playing back the difference signal with as little distortion as possible (you can hear this signal if you play a CD-4 record and turn down both separation pots to their bare minimum).

what cart/stylus are you using at the mo?
I'm concerned about TT adjustability too. That is partly why I've been asking for TT recommendations.

I have several CD-4 test/set-up discs. Pretty sure at least one of them has the 30kHz tone. They don't necessarily announce that on the jacket though.

Please elaborate whether you're inquiring about my carts or my styluses. They are not the same thing, right? I have a Pickering XV-15/625E on one TT and a Shure of some kind on the other. It takes an N-91E stylus.
 
I'm concerned about TT adjustability too. That is partly why I've been asking for TT recommendations.

I have several CD-4 test/set-up discs. Pretty sure at least one of them has the 30kHz tone. They don't necessarily announce that on the jacket though.

Please elaborate whether you're inquiring about my carts or my styluses. They are not the same thing, right? I have a Pickering XV-15/625E on one TT and a Shure of some kind on the other. It takes an N-91E stylus.
Both Bob Romano and myself use one of these modern Technics that we feel work great and are built like a tank:

https://us.technics.com/products/direct-drive-turntable-system-sl-1200mk7
I had previously tried one of the Pro-Ject models; that felt like a toy to me compared to the Technics, and it had arrived new in box and was dead on arrival, wouldn't even turn on. How the heck does that pass through quality control :unsure:
 
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