CD-4 Disc Demodulator JVC 4DD-5 . Please help.

[Doug G.]

Don't worry. I have had many, many years experience cleaning records and styli.

It isn't dish soap. It is dish detergent. There is a big difference between soap and detergent. And detergent will never harm record vinyl. You just need to thoroughly rinse it off. No problem. Soft water is OK. The distilled water thing is way overstated.

Water and alcohol alone isn't really enough as there is no surfactant to loosen dirt stuck in the grooves. Detergent serves that purpose. That's why you use it on dishes. Water alone will not completely clean.

And one good wet cleaning in the life of a used record is all that should ever be necessary. I don't clean new records as I believe that to be a bit ridiculous.D

Doug

 

[RSilverman]

I've had best results with wood glue and really good results washing in the sink with some dish soap. Never had an issue with the label peeling off, either.

 

[Doug G.]

Labels generally are not permanently harmed if they get wet. Most label dyes are water proof. The exceptions are some from the fifties which will run in water. Those are easy to recognize.

When cleaning a record, just don't purposely aim the water at the label and they will be fine after they dry.

If you are concerned about this, however, you can buy a label protector or make your own.

Doug

 

[Quad Linda]

I've always used Keester solder.

Maybe I'll attempt a transplant as a way to start building soldering skills. Or just chuck it. Either one.

 

[RSilverman]

If I were to mess with one of my bad ones -- the one with two strong channels and full sound, but no decoding on the right - can someone suggest what parts I'd replace on the circuit board? I don't have any meters or equipment other than a soldering iron and some solder. I have three of these bad jvcs to play with and don't mind totally trashing them if I can get one really good one out of the mix.

 

[RSilverman]

On another note - besides the above question - my Lou Dorren record cleaner came today. I cleaned my Enoch Light CD4 like mad, and there's no real different. The CD4 light flashes a tad, but that's it. There's not a scratch on the album. It looks mint. As I mentioned, I played it through entirely once and it was perfect. I demoed parts of it for a friend once and other than that, it's been tucked away. I guess the grooves with the rear information are totally destroyed. I have dollar store CD4s with loads of surface noise, warps, etc., that light up the radar fine, but this one.... stereo only.

 

[jrlinks]

I am very curious about your Enoch Light LP.
I found this site where there is a list of his albums and which quad format they were issued in.
Labeling was confusing as some only had QD as the suffix to the album number which did not
define the encoding used.
Please have a look.
Is it possible your LP is not CD-4?
Some high frequency content can cause the CD-4 radar led to flash on stereo lps.

Sample quoted from the web page.

While A&M used QS, SQ, and finally settled on CD-4, Project 3 used all three and then settled with SQ for their final quad releases. Buyers of Project 3 quad albums would sometimes not even know what format they would find when they opened the album. Many of these discs only stated "QD" on the label number printed on the album cover. The buyer could actually end up with EV, QS, SQ, or in some cases CD-4 records and not even know it! In some cases, EV, CD-4, QS and SQ stickers were used to indicate the format when it was not printed on the jacket artwork.

A History of Project-3 Quadraphonic Record Albums

 

[Quad Linda]

CD-4 Quadradisc of Enoch Light's Charge should look like this:


Other pressings don't indicate CD-4. I'd expect them to be QS encoded:

 

[RSilverman]

Yep. It's QS. I just matched the number against the quad discography. I feel like a frackin' idiot. I could swear I played it through my demodlator on my receiver when I first got it with no distortion and quad effect, but I must have been high or drunk or something. I don't know why I thought this was CD4. I have another Enoch Light that says CD4 on it like the sticker that QuadLinda shows above.

Slaps head. And wonders now about investing 40 bucks in Lou Dorren's cleaner. Is that stuff even any good? I have two things of it now. If it's decent stuff, it doesn't hurt to have good record cleaner around.

I'm going back to Game of Thrones and hanging my head in semi-shame. How did I think I was playing CD4 when I got this thing? Ayieeeee....... I need a drink. Good thing I have one sitting next ti me.

 

[jrlinks]

Yes Lou's cleaning system is excellent for ALL lps.
Background noise is reduced as well as small clicks and pops.

BTW you are welcome for my researching and discovering your problem.

 

[Quad Linda]

Here's how Mark Anderson's Discography lists it:

Charge. Project 3 PR5073QD (QS), PR5073SQ (SQ),
PR5073CD4 (CD4), PR4C-5073 (QR), PRQ8-5073 (Q8)

In other words, it was released in every Quad format that was being pressed/duplicated at the time. QD suffix would be QS.

Yes, depending on the cartridge and demodulator, many 2 ch LP's will light up CD-4 radar either intermittently or constantly. This is very common, since any ultra high frequency information will trigger that light. If you listen, there usually isn't a Quad effect, since there isn't a carrier signal on the LP. There may be a decent synthesized or "decoded" effect, but this is serendipitous.

 

[Quad Linda]

Command was pressed and distributed by ABC. Many Command titles, especially stereo pressings list Grand Award Records, which is also ABC. ALL ABC & Dunhill Pop/Blues/Soul titles are RM/QS and say Command Quadraphonic. Most ABC Impulse jazz titles and Bluesway blues titles from '72 - '76 are RM/QS encoded, but do not prominently say so. Compatible Quadraphonic, meaning QS, is their usual verbiage. impulse and Bluesway titles did not say Command Quadraphonic. Titles issued in stereo on Command could have been released as any Quad format. Being that they were distributed by ABC, they were most likely to be QS encoded.

Note no reference to Quad on front cover:


Note Compatible stereo/Quad (Regular Matrix) verbiage on bottom left of back cover:
http://1.bp.blogspot.com/-4w8bsq8tQ...AADrc/8VtR8U-slus/s1600/CoverIllustration.jpg

 

[RSilverman]

I have this Keith Jarrett one. It's a great album. I noticed in the discography there's a few Keith Jarrett quads. I have most if them now, but my QS decoding via the 2020 isn't the best. Waiting on the new gizmo from Australia.

 

[ndiamone]

Yes Lou's cleaning system is excellent for ALL LPs.

Is it any better than the Australian stuff in the big bottle that all the archivists use? It works just like wood glue, and then it has a small bottle of what appears to be glorified Discwasher to use afterward.

 

[RSilverman]

I have no idea what the Aussie stuff is. I haven't messed much with the Lou Dorren cleaner yet, but the idea of it is, you use this lint free wipes to spread the cleaner into the grooves. You then dry it and play back 1/3 of the record without the sound on. The needle pushes the dirt from the grooves so after 1/3 you raise the arm and clean the needle. Then you repeat two more times. I will say from the little I saw, it really does lift the gunk out of the grooves, and even though you have to play the record though, it's less time-consuming then wood glue.

 

[ndiamone]

I have no idea what the Aussie stuff is.

http://recordrevirginizer.com/about.html

I haven't messed much with the Lou Dorren cleaner yet, but it's less time-consuming then wood glue.

And you don't worry that playing the record just drives the gunk further into the grooves?

 

[RSilverman]

I dunno what I worry about. I just got this stuff yesterday.

 

[RSilverman]

For what it's worth, I followed the instructions and cleaned my Joni Mitchel "Court and Spark" CD4 with the Lou Dorren cleaner tonight. when I played it last, it played OK, but was quite noisy. after the cleaner, it's almost perfect. I'm quite impressed. You can see the gunk the needle lifts out of the grooves. This stuff is no joke.

 

[quadsearcher]

For what it's worth, I followed the instructions and cleaned my Joni Mitchel "Court and Spark" CD4 with the Lou Dorren cleaner tonight. when I played it last, it played OK, but was quite noisy. after the cleaner, it's almost perfect. I'm quite impressed. You can see the gunk the needle lifts out of the grooves. This stuff is no joke.

That sounds good. I'm wary of using my new AT stylus as a cleaning tool though, I wonder if it would still clean as well using a relatively cheap elliptical stylus, then switch to the Shibata for actual play? Any mention of that in the instructions?

 

[RSilverman]

He says for CD4 to use shibata or microline stylus. Elliptical OK for everything else.