JVC CD-4 demodulator 4DD-10

[Manimarco]

I recently picked up a Technics quad (It is in another post) But i got this also, A JVC CD-4 demodulator 4DD-10. I have never used one but thought it might be good to have with the Technics. Any info on this would be great. Thanks

 

[Manimarco]

Does anyone here have one of these? I am having a hard time finding another one anywhere. The only info I have found is a old add someone uploaded to the net.

http://www.cieri.net/Documenti/Altri marchi/JVC - The World of JVC 4-Channel Sound.pdf

 

[Manimarco]

Well I can't find much info on this and I don't have a quad TT so on ebay it goes!

 

[sjcorne]

Well I can't find much info on this and I don't have a quad TT so on ebay it goes!

No such thing as a "quad TT"...to get good CD-4 performance you can use any model as long as it has short and low-capacitance cables. You do need a quad cartridge (with a shibata tip stylus) though. For CD-4 playback I use a Technics SL-1500 with a JVC 4MD-20x cartridge.

To properly use the demod you have to run the turntable wires into it, then run the 4 channel outs to a receiver. You then need a special adjustment record to properly tune the separation and carrier controls.

 

[quadanasaziland]

No such thing as a "quad TT"...to get good CD-4 performance you can use any model as long as it has short and low-capacitance cables. You do need a quad cartridge (with a shibata tip stylus) though. For CD-4 playback I use a Technics SL-1500 with a JVC 4MD-20x cartridge.

To properly use the demod you have to run the turntable wires into it, then run the 4 channel outs to a receiver. You then need a special adjustment record to properly tune the separation and carrier controls.

Well I guess, technically but in the 70's there were lines of "quad tables" by Sansui, Dual, JVC, Pioneer and others that featured the low capacitance connects and Shabata style tips that played cd-4, sq, qs and stereo lps so one TT did every thing.

 

[winopener]

Well I can't find much info on this and I don't have a quad TT so on ebay it goes!

You may regret it... i have one of these and works very well with several cart, among these the Audiotechnica 331LC and the 440ML. Slightly better than the 4dd5.
Have also a Groovetool still packed that waits for a test with CD4 records.
Unfortunately i don't have any literature on the 10.

 

[Manimarco]

You may regret it... i have one of these and works very well with several cart, among these the Audiotechnica 331LC and the 440ML. Slightly better than the 4dd5.
Have also a Groovetool still packed that waits for a test with CD4 records.
Unfortunately i don't have any literature on the 10.

I don't really know if I will need it. My Technics SA 8000X has demodulation in it but it may not be anywhere as good as the JVC?

 

[winopener]

I don't really know if I will need it. My Technics SA 8000X has demodulation in it but it may not be anywhere as good as the JVC?

I am not sure about the CD4 circuit into the SA 8000X, but if it is the same as their standalone cd4 decoder, it need a special cartridge (semiconductor).The 4dd10 works with all carts.

 

[Quadzilla]

I am not sure about the CD4 circuit into the SA 8000X, but if it is the same as their standalone cd4 decoder, it need a special cartridge (semiconductor).The 4dd10 works with all carts.

There is a switch on the back of the Technics to choose between semiconductor and moving magnet cartridges.
Don't forget to clean the cartridge selector switch as well as the CD-4 subcarrier level adjustment switch above it.
Use DeoxIT, because they could have been left in the same positions for many years ... https://www.parts-express.com/caig-deoxit-d5s-6-spray-5-oz-with-perfect-straw--341-200

 

[surround.sound.enthusiast]

If you haven't put the demodulator up for auction yet, it's worth trying it out versus the onboard demodulator in your Technics receiver. If it actually performs as good or better than a 4DD-5 like winopener says, then it's probably a pretty good unit. I was going to say that it looked relatively equivalent to a 4DD-5 in terms of controls an connections. Actually, looking through my photographs, that is a JVC re-badge of a Victor CD4-2, and I've almost never seen either model. The thing that tipped me off to look was the separation controls on the front - Victor was considerate about putting them on the front instead of the back, where you have to struggle with wiring to to adjust them during set-up.

 

[The Quadfather]

JVC demodulators aren't a rebadge of anything. JVC invented CD-4 and all their demodulators are pure JVC. More than likely, the Victor demodulator you speak of is actually a JVC. Some of the Marantz demodulators also had JVC boards in them. Same with Sylvania. (just a rebranded JVC 4DD5) The JVC demods are some of the best. I think the 4DD10 was an enhanced 4DD5 and has discrete components in it's preamp instead of integrated circuits. Otherwise very similar. The frontal controls are nice but not necessary. Once they are set, you don't have to mess with them. I see you posted in February, It is now August. If you did sell that demod, someone got a good one. If not, hook it up and see if it works. It's worth fixing.

 

[bigbillquad]

Hi. All

After comments on a JVC CD4- 50 demodulator I bought it a why`ll ago and gave it a brief test it performs better than my 4 DD-5 unit, but I have not done a comprehensive full test yet, does anybody have information on this unit.
Bill...

 

[DuncanS]

Hi. All

After comments on a JVC CD4- 50 demodulator I bought it a why`ll ago and gave it a brief test it performs better than my 4 DD-5 unit, but I have not done a comprehensive full test yet, does anybody have information on this unit.
Bill...

View attachment 34473 View attachment 34474 View attachment 34475

Have a look at https://www.vinylengine.com/library/jvc/cd4-50.shtml

 

[The Quadfather]

Wow, I've never seen one with delay controls. I suspect that's to fine tune the delay to max out separation. It would adjust the subcarrier delay before the remix stage. If it's not that, it probably delays the rear channels to make the room sound larger. I suspect it's the former. More than likely, this model is intended to be a reference standard demodulator. Something other demodulators would be compared with. I would hang on to that one, and listen to it.

 

[Soundfield]

Wow, I've never seen one with delay controls. I suspect that's to fine tune the delay to max out separation. It would adjust the subcarrier delay before the remix stage. If it's not that, it probably delays the rear channels to make the room sound larger. I suspect it's the former.

I suspect you are correct - the maximum delay offered by that knob is apparently 50uS which represents 1.7 cm so not making the room very much bigger!

 

[fredblue]

ooh i say! what a tasty looking bit of kit!

I notice it has a blend switch, how "blended" do things get with it engaged?
my little Grundig CD-4 demodulator has a blend switch round the back (wish it looked as impressive as this JVC beauty of yours!!) but I don't use it as it seems to defeat the point of CD-4 (imho!).

also, how do you make the adjustment for the 30khz carrier?
is it on the underside of the unit, like the 4DD-5?
or is it automatic like the Grundig Quadro and Marantz CD-400B?

one thing this does have in common with the diminutive Grundig is, afaik, they both use the "Holy Grail" CD4-392 chip.. how cool is that!

 

[bigbillquad]

ooh i say! what a tasty looking bit of kit!

I notice it has a blend switch, how "blended" do things get with it engaged?
my little Grundig CD-4 demodulator has a blend switch round the back (wish it looked as impressive as this JVC beauty of yours!!) but I don't use it as it seems to defeat the point of CD-4 (imho!).

also, how do you make the adjustment for the 30khz carrier?
is it on the underside of the unit, like the 4DD-5?
or is it automatic like the Grundig Quadro and Marantz CD-400B?

one thing this does have in common with the diminutive Grundig is, afaik, they both use the "Holy Grail" CD4-392 chip.. how cool is that!

Hi. fredy

I am dying to get into my CD-4 collection with this baby but dealing with Q8 & Q4 lately I have my system set up with Reel to Reel & my Quad 8track player Its the old story of no room for everything at your fingertips..

Yes its automatic for the 30khz carrier in photo 2 it has... "ready & play lights"... I have not down loaded the manual yet so not fully confers yet with this unit but it was a great find I bought it her in little old NZ would you believe it....

O the blend switch you would only use it with a well worn LP as you say it sacrifices separation for less sand paper nose...

 

[surround.sound.enthusiast]

JVC demodulators aren't a rebadge of anything. JVC invented CD-4 and all their demodulators are pure JVC. More than likely, the Victor demodulator you speak of is actually a JVC.

Sorry for mis-speaking Quadfather. That's actually what I meant, that they were the same device, just labelled two different models under the JVC/Victor umbrella. I have no idea which of the two brands would have had a given model "first".
I know you're knowledgeable in CD-4 because I've used your forum advice in setting up my CD-4 system: CD-4 was developed by JVC, but started life in Japan (didn't it?), who would you guess might have had an identical offering like the 4DD-10 / CD4-2 or 4DD-5 / CD-30 "first"? Probably varied from offering to offering. I'm not clear on how the business hierarchy was between JVC and Victor.

Frontal controls are nice for easier fine tuning of channel separation. My CD4-10 and UDA-100 both have this - fewer times having to reach around the back of the demodulator to adjust the separation (but nevermind carrier signal adjustment).

 

[EmeraldCity]

JVC stands for Japan Victor Company. JVC and Victor and one and the same.

 

[surround.sound.enthusiast]

Yeah, I knew that. Thanks though in case anyone else reading didn't know that yet.