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

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J. PUPSTER

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I want to make it abundantly clear, that I have had some success with CD-4 (quadradisc.) But recently much more failure, primarily due to two things:

1- sandpaper effect &
2- issues with old 70's era gear (hum)

When CD-4 works well, the results can be amazingly great. Very discrete mixes brought to life. But let's not fool ourselves, CD-4 is a DEAD format for all practical purposes. I'm not aware of a single bit of hardware that supports/functions with it since the 70's (I'm sure others will correct me if I'm wrong here!)
Heck, even in the whole of this very niche QQ surround/Quad forum of supposedly over 10,000 members; I wouldn't be surprised if there're only a few dozen actively listening directly to CD-4 albums.

So when it comes to support for hardware, a grand search must be undertaken for places like qrxrestore etc. that still have the knowledge and abilities to do the job right.

Long before I started working towards a CD-4 system of my own, I was a non-member lurker here taking in the knowledge the forum offered. And once I took the plunge and got into the forum, I found friends with similar interests to help me along and further my education. To date, I believe I've pretty much read most of what's offered here for CD-4 information. But that doesn't necessarily translate to a golden ticket of success. The struggle must be endured to get there.

It took me till my 3rd try at a turntable before I found one I liked and fit the bill. It's a Technics SL1200MK7. Then I had to find the right carts. I started with an AT440MLb and that did a decent job, but I felt a little more separation could be had, so I changed over to an older AT15S (Shibata) which I've been happy with, especially for CD-4. I still have a new AT VM740ML (MicroLine) to give a try; however that's one area I don't relish, is changing out carts and having to adjust/realign each time.

I've actively been buying CD-4 albums (primarily through sellers on discogs) in NM or better condition which is another added expense. Of course that's all part of the cost of the hobby, I don't really mind that, the hunt is an enjoyable aspect for me. I had a nice little stack built up and cleaned ready to go and Demodulate/Convert to digital also; when I discovered my QRX-8001 had a couple of new issues. First the Left Rear channel is cutting in and out, but I could still rip/convert the LP. Then I discovered it also developed some nasty hums (both a lower level and some higher toned hums.) Well the Sansui had already been gone over a couple years ago by qrxrestore along with the Holy Grail alignment; I can tell you, along with the initial cost of the Sansui and the qrxrestore work (along with shipping costs for the beast) it ain't cheap folks! OK, so I'm not ready to send this back again to qrxrestore for more work. I can afford it just fine, I just hate all the tearing down of my system, packing up and shipping out, etc. etc.

So I decided to look for a stand alone Demodulator while I sit on the Sansui issue some more and chew on it. I found a nice Marantz CD-400B that was listed on eBay as a NOS, and it looked every bit of a new in box type unit. So I bid on it and got it for a measly $198 with shipping. Not bad, but I knew full well that even though it looked new in box, who knows what it's really been through and also that for a nearly 50 year piece of gear that doesn't count for much. But for that money, and feeling somewhat wanting of something right away I bit on it. Well it turns out it works pretty well except it too has a mild low level hum. I thought at first, after doing some research, and hearing some vocalization in the hum perhaps I have a ground loop issue. But, after doing some other testing on my setup of:

A: Recording a regular LP through a MOTU UltraLite mk4 with just my Technics SL1200MK7 and Rotel preamp, no hum!
B: Recording a QS LP through a MOTU UltraLite mk4 with my Technics SL1200MK7 and through my Surround Master v2 for Quad, and again no hum!

All that I've talked about here on the open forum is only a tiny tip of the ice-berg as to conversations I've had with very experienced and knowledgeable folks in private messages about my CD-4/Quad issues. They all have been very valuable friends and supportive in trying their best to help me out. I feel I am sooo very close to have it all working as it should, only if the old gear would hold up. But that's the rub right!

We're now working with the idea that the hum is possibly caused (the Marantz Demod.) by either a dry joint or a failing electrolytic capacitor. None of that means much to me, as I don't have experience in working on electronics, and have no interest in learning at my advanced age. So now where does that leave me? I guess I find someone that can work on such things, kindly offer to have a go at fixing my limping Marantz; or I find another old 70's piece of Quad gear to throw money at :unsure:

From my perspective CD-4 can be a beautiful lady waiting to be aurally caressed, or as more often, it appears to me at least, a cold hearted soul crushing Bitch!
Yes I'm still in the fight, but my time is running short if I'm going to fully realize this dream.

Here's a sample of the Marantz hum (the Marantz was turned on at about 27 sec. into this one min. mp3 sample) and boosted about 30 dbs so you can hear the hum better.
 

Attachments

  • HUM TEST 1 min. at 27 sec Marantz +30db.mp3
    2.3 MB

quadsearcher

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I want to make it abundantly clear, that I have had some success with CD-4 (quadradisc.) But recently much more failure, primarily due to two things:

1- sandpaper effect &
2- issues with old 70's era gear (hum)

When CD-4 works well, the results can be amazingly great. Very discrete mixes brought to life. But let's not fool ourselves, CD-4 is a DEAD format for all practical purposes. I'm not aware of a single bit of hardware that supports/functions with it since the 70's (I'm sure others will correct me if I'm wrong here!)
Heck, even in the whole of this very niche QQ surround/Quad forum of supposedly over 10,000 members; I wouldn't be surprised if there're only a few dozen actively listening directly to CD-4 albums.

So when it comes to support for hardware, a grand search must be undertaken for places like qrxrestore etc. that still have the knowledge and abilities to do the job right.

Long before I started working towards a CD-4 system of my own, I was a non-member lurker here taking in the knowledge the forum offered. And once I took the plunge and got into the forum, I found friends with similar interests to help me along and further my education. To date, I believe I've pretty much read most of what's offered here for CD-4 information. But that doesn't necessarily translate to a golden ticket of success. The struggle must be endured to get there.

It took me till my 3rd try at a turntable before I found one I liked and fit the bill. It's a Technics SL1200MK7. Then I had to find the right carts. I started with an AT440MLb and that did a decent job, but I felt a little more separation could be had, so I changed over to an older AT15S (Shibata) which I've been happy with, especially for CD-4. I still have a new AT VM740ML (MicroLine) to give a try; however that's one area I don't relish, is changing out carts and having to adjust/realign each time.

I've actively been buying CD-4 albums (primarily through sellers on discogs) in NM or better condition which is another added expense. Of course that's all part of the cost of the hobby, I don't really mind that, the hunt is an enjoyable aspect for me. I had a nice little stack built up and cleaned ready to go and Demodulate/Convert to digital also; when I discovered my QRX-8001 had a couple of new issues. First the Left Rear channel is cutting in and out, but I could still rip/convert the LP. Then I discovered it also developed some nasty hums (both a lower level and some higher toned hums.) Well the Sansui had already been gone over a couple years ago by qrxrestore along with the Holy Grail alignment; I can tell you, along with the initial cost of the Sansui and the qrxrestore work (along with shipping costs for the beast) it ain't cheap folks! OK, so I'm not ready to send this back again to qrxrestore for more work. I can afford it just fine, I just hate all the tearing down of my system, packing up and shipping out, etc. etc.

So I decided to look for a stand alone Demodulator while I sit on the Sansui issue some more and chew on it. I found a nice Marantz CD-400B that was listed on eBay as a NOS, and it looked every bit of a new in box type unit. So I bid on it and got it for a measly $198 with shipping. Not bad, but I knew full well that even though it looked new in box, who knows what it's really been through and also that for a nearly 50 year piece of gear that doesn't count for much. But for that money, and feeling somewhat wanting of something right away I bit on it. Well it turns out it works pretty well except it too has a mild low level hum. I thought at first, after doing some research, and hearing some vocalization in the hum perhaps I have a ground loop issue. But, after doing some other testing on my setup of:

A: Recording a regular LP through a MOTU UltraLite mk4 with just my Technics SL1200MK7 and Rotel preamp, no hum!
B: Recording a QS LP through a MOTU UltraLite mk4 with my Technics SL1200MK7 and through my Surround Master v2 for Quad, and again no hum!

All that I've talked about here on the open forum is only a tiny tip of the ice-berg as to conversations I've had with very experienced and knowledgeable folks in private messages about my CD-4/Quad issues. They all have been very valuable friends and supportive in trying their best to help me out. I feel I am sooo very close to have it all working as it should, only if the old gear would hold up. But that's the rub right!

We're now working with the idea that the hum is possibly caused (the Marantz Demod.) by either a dry joint or a failing electrolytic capacitor. None of that means much to me, as I don't have experience in working on electronics, and have no interest in learning at my advanced age. So now where does that leave me? I guess I find someone that can work on such things, kindly offer to have a go at fixing my limping Marantz; or I find another old 70's piece of Quad gear to throw money at :unsure:

From my perspective CD-4 can be a beautiful lady waiting to be aurally caressed, or as more often, it appears to me at least, a cold hearted soul crushing Bitch!
Yes I'm still in the fight, but my time is running short if I'm going to fully realize this dream.

Here's a sample of the Marantz hum (the Marantz was turned on at about 27 sec. into this one min. mp3 sample) and boosted about 30 dbs so you can hear the hum better.
Yes, that sounds like a poor connection somewhere in the Marantz. It could be in a switch, solder connection, or similar. It is acting as a diode, detecting a nearby radio transmitter, as semi-conducting connections sometimes do. There may also be filter problem in the power supply, or not.
I have the same model, and hope to find time to try a different turntable/cartridge/stylus/alignment/cables etc, to be able to play more than the first two songs before distortion sets in.
No hum or radio stations on mine, just an inadequate turntable setup.
 

gvl_guy

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1) What is the best (or several best) TT(s) to acquire?
2) What is the best cart (or several best) cart(s) to acquire?
3) What is the best demod (or several best) demod(s) to acquire?
When it comes to turntables, I've always been in a quandary. Most don't tell you the capacitance of their wiring and that makes a difference with CD-4. I would suggest a turntable from one of the CD-4 proponents from back in the 70s since they are likely "automatically" good for CD-4 - like Technics or JVC. My Technics SL-1700 semi automatic has always been perfect for it.

Cartridge - now that's a HUGE quandary. I have 3 good enough for CD-4. A Shure M24H that I bought new back in the 70s that is my favorite. Excellent sound in stereo or CD-4. Sounds better than my Stanton 680EE, too. A couple of years ago, I bought a NOS JVC MD-20x. It's very good. No issues, but the Shure sounds better to me. The JVC is actually a re-branded Audio Technica. There are lots of those around and you can likely get a replacement stylus easier. And recently, at an estate sale, I bought a Grado F1+. I haven't had a lot of time to fool with it yet, but so far it seems okay.

I've tried and tried to do research into the "best demodulator" and my head spins every time. o_O Everyone has an opinion. Back in the 70's, my Pioneer QX-949A had one built in and it was fine. My current Sansui 9001 has one built in, also fine. (By "fine" I mean that I don't have a lot of issues with the sound, if you don't mind a crackle or pop every so often. I mean, it's CD-4, so....) I want to buy a separate outboard model as a backup and there are just so many out there and at prices that are all over the place. Some you have to adjust the carrier levels, others you don't. There are a few of the "newer" ones that have no separation to be adjusted. Some have lots of lights and dials, some have pretty much a power button and a dial selector. I STILL don't know what kind to buy. I think it's actually hit or miss. But if it dies, it's dead. I think it's nearly impossible to find parts to fix them.
 

4-earredwonder

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I want to make it abundantly clear, that I have had some success with CD-4 (quadradisc.) But recently much more failure, primarily due to two things:

1- sandpaper effect &
2- issues with old 70's era gear (hum)

When CD-4 works well, the results can be amazingly great. Very discrete mixes brought to life. But let's not fool ourselves, CD-4 is a DEAD format for all practical purposes. I'm not aware of a single bit of hardware that supports/functions with it since the 70's (I'm sure others will correct me if I'm wrong here!)
Heck, even in the whole of this very niche QQ surround/Quad forum of supposedly over 10,000 members; I wouldn't be surprised if there're only a few dozen actively listening directly to CD-4 albums.

So when it comes to support for hardware, a grand search must be undertaken for places like qrxrestore etc. that still have the knowledge and abilities to do the job right.

Long before I started working towards a CD-4 system of my own, I was a non-member lurker here taking in the knowledge the forum offered. And once I took the plunge and got into the forum, I found friends with similar interests to help me along and further my education. To date, I believe I've pretty much read most of what's offered here for CD-4 information. But that doesn't necessarily translate to a golden ticket of success. The struggle must be endured to get there.

It took me till my 3rd try at a turntable before I found one I liked and fit the bill. It's a Technics SL1200MK7. Then I had to find the right carts. I started with an AT440MLb and that did a decent job, but I felt a little more separation could be had, so I changed over to an older AT15S (Shibata) which I've been happy with, especially for CD-4. I still have a new AT VM740ML (MicroLine) to give a try; however that's one area I don't relish, is changing out carts and having to adjust/realign each time.

I've actively been buying CD-4 albums (primarily through sellers on discogs) in NM or better condition which is another added expense. Of course that's all part of the cost of the hobby, I don't really mind that, the hunt is an enjoyable aspect for me. I had a nice little stack built up and cleaned ready to go and Demodulate/Convert to digital also; when I discovered my QRX-8001 had a couple of new issues. First the Left Rear channel is cutting in and out, but I could still rip/convert the LP. Then I discovered it also developed some nasty hums (both a lower level and some higher toned hums.) Well the Sansui had already been gone over a couple years ago by qrxrestore along with the Holy Grail alignment; I can tell you, along with the initial cost of the Sansui and the qrxrestore work (along with shipping costs for the beast) it ain't cheap folks! OK, so I'm not ready to send this back again to qrxrestore for more work. I can afford it just fine, I just hate all the tearing down of my system, packing up and shipping out, etc. etc.

So I decided to look for a stand alone Demodulator while I sit on the Sansui issue some more and chew on it. I found a nice Marantz CD-400B that was listed on eBay as a NOS, and it looked every bit of a new in box type unit. So I bid on it and got it for a measly $198 with shipping. Not bad, but I knew full well that even though it looked new in box, who knows what it's really been through and also that for a nearly 50 year piece of gear that doesn't count for much. But for that money, and feeling somewhat wanting of something right away I bit on it. Well it turns out it works pretty well except it too has a mild low level hum. I thought at first, after doing some research, and hearing some vocalization in the hum perhaps I have a ground loop issue. But, after doing some other testing on my setup of:

A: Recording a regular LP through a MOTU UltraLite mk4 with just my Technics SL1200MK7 and Rotel preamp, no hum!
B: Recording a QS LP through a MOTU UltraLite mk4 with my Technics SL1200MK7 and through my Surround Master v2 for Quad, and again no hum!

All that I've talked about here on the open forum is only a tiny tip of the ice-berg as to conversations I've had with very experienced and knowledgeable folks in private messages about my CD-4/Quad issues. They all have been very valuable friends and supportive in trying their best to help me out. I feel I am sooo very close to have it all working as it should, only if the old gear would hold up. But that's the rub right!

We're now working with the idea that the hum is possibly caused (the Marantz Demod.) by either a dry joint or a failing electrolytic capacitor. None of that means much to me, as I don't have experience in working on electronics, and have no interest in learning at my advanced age. So now where does that leave me? I guess I find someone that can work on such things, kindly offer to have a go at fixing my limping Marantz; or I find another old 70's piece of Quad gear to throw money at :unsure:

From my perspective CD-4 can be a beautiful lady waiting to be aurally caressed, or as more often, it appears to me at least, a cold hearted soul crushing Bitch!
Yes I'm still in the fight, but my time is running short if I'm going to fully realize this dream.

Here's a sample of the Marantz hum (the Marantz was turned on at about 27 sec. into this one min. mp3 sample) and boosted about 30 dbs so you can hear the hum better.My advice,


MY ADVICE, PUPSTER ๐Ÿถ ...... GET A HORSE๐ŸŽ
 

4-earredwonder

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The demodulator I currently have is a JVC 4DD-10.
No idea how well it works. The power indicator lights up.

See the source image

BAGGY IN CD~4 MODE!
 

edisonbaggins

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YOUR LIFE ... IN SURROUND ... DEPENDS ON IT!
If only CD-4 advice weren't all over the place...
I just read earlier today that a Pickering cart of some kind is a top choice. Hopefully it can work with my Pioneer PL-12D?
I'm ok looking around for the exact right TT. Don't get me wrong.
 

4-earredwonder

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If only CD-4 advice weren't all over the place...
I just read earlier today that a Pickering cart of some kind is a top choice. Hopefully it can work with my Pioneer PL-12D?
I'm ok looking around for the exact right TT. Don't get me wrong.
Which is why I switched to QUAD OPEN REEL after spending a small fortune on a CD~4 demodulator, cartridge etc. Couldn't take the DRAMA. Unfortunately, not a lot of titles were available on QUAD OPEN REEL but the ones I did procure sounded so much better to my ears .... especially the Dolby b encoded variety!
 

fizzywiggs41

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Back ,...waaaay back when I had CD-4 , I encountered a "hum" problem that was driving me nuts .

And with my system ....it could been any where , put I persisted in looking at all connections and found it.
My cartridge wasn't making full contact with the four metal straps on the tonearm . Those strips I found had actually slipped down ,not much ,but enough to cause the problem. Easy fix ,btw I pushed the tiny plastic plate with the 4 contact strips, back ...upwards.

Best cartridge, well there are many good ones ,but I'd stick with a proven winner ,the Shure M 24H . Had a JVC 4MD 20X , and I was not overly impressed. Now JVC also had in late 70's , the X 1 , which is likely as good as a Shibata gets.

Dual made very good turntables for CD-4 back when ,but my understanding is there are many newer turntables of various makes that work just fine.

Best outboard Demodulator ?.... there were many decent ones .... decade's back , Panasonics, Sansui , and Harmon Kardon. I had a Harmon Kardon 44 + , with no problems.
But JVC , and Technics , had some in the mid 70's that are considered superb . That may also apply to a mid 70's Panasonics as well.
Also I would think that Grundig made a decent demodulator. Any German made should be amongst the best as they had excellent hifi gear in my opinion and high quality standards.
 

edisonbaggins

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Best cartridge, well there are many good ones ,but I'd stick with a proven winner ,the Shure M 24H . Had a JVC 4MD 20X , and I was not overly impressed. Now JVC also had in late 70's , the X 1 , which is likely as good as a Shibata gets.
Another member recommended the Pickering XUV-4500Q. Thoughts as to how it compares to the above?
 

4-earredwonder

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There are multitudes of great, discrete Quad albums available nowhere else.

I'm in it for the long haul Ralphie!
I of course was being facetious, JP....besides horses are WAAYYY higher maintenance than CD~4. My problem .... I could not tolerate the ticks, pops, swishes and other anomalies associated with viny as these 'aberrations' are NOT extant on the master tapes. Instead I have concentrated on a SOTA digital system where I don't have to live with the 'eccentricities' of vinyl most especially on classical and solo piano recordings.
 

fizzywiggs41

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Another member recommended the Pickering XUV-4500Q. Thoughts as to how it compares to the above?


Never had one ,but some of those top of the line Pickering and Empire were too pricy for me..... but were highly regarded. The old saying of you pay for what you get applies ,me thinks, Mike .

If you can get a hold of the Shure M 24 H , well that's my highest recommendation , if not then try the JVC X 1, also a late entry cartridge.
What's weird about that Shure (and JVC) is that they came out late in 76 !!! That's when CD-4 was dying.
 

edisonbaggins

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Never had one ,but some of those top of the line Pickering and Empire were too pricy for me..... but were highly regarded. The old saying of you pay for what you get applies ,me thinks, Mike .

If you can get a hold of the Shure M 24 H , well that's my highest recommendation , if not then try the JVC X 1, also a late entry cartridge.
What's weird about that Shure (and JVC) is that they came out late in 76 !!! That's when CD-4 was dying.
They should insert just fine into my tonearm head thingy?
My Pioneer PL-12D is currently sporting a Shure N-91E.
 

kfbkfb

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The Pioneer PL-12D owners manual doesn't mention CD-4 (Pioneer was a big supporter of CD-4).

(one way to easily test your demod - plug in the PL-12D+Shure into it - most stereo carts will have some output in the FM carrier frequency range and will at least turn on the CD-4 radar light [sound will be distorted], it won't hurt the demod)


IMHO, the main issue with old CD-4 carts is stylus availability (the CD-4 system was investigated in depth a few years ago when the all software CD-4 demodulator was being developed, here's a recommendation about carts for CD-4):


Kirk Bayne
 
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