Advice on adding CD-4 / Quadradisc capability to my system

[Electronic M]

I'm looking for advice on the least expensive 'good' way to add the CD-4 format to my existing quad system.

A few months back I acquired a couple of albums in this format that appear to have intact sub-carriers. After reading enough to glean that I need a CD-4 decoder to get quad playback as well as a proper pickup cartridge and needle in order to avoid erasing the quad difference sub-carriers on playback, I've decided not to play the discs until I have at least the latter on hand.

Seeing as I'm a college student I don't have much money(don't like to spend it either) so I'm basically limited to a 50$ max budget for a decent cartridge and styli combo.

From what I understand(correct me if I'm wrong) the two key things that make a pickup suitable for CD-4 are a Shibata cut stylus and a cartridge with the ability to reproduce frequencies at least as high as 45kHz.

So far the best place I could think of to look for one for sale was ebay, but with a complete cartridge and needle ALONE running north of 150$(holey cow! IMHO it should come installed in a NICE TT for that kind of money) I'm rather apprehensive towards buying one.

My next thought was to look at my post 1970 TTs and have my fingers crossed that one of them might be equipped with a suitable cart and styli, but I'm not sure how to go about identifying the ones in my TTs.

Another thought that came to mind is that considering most opinions I've read regard the CD-4 carts and styli as being a major advancement from previous designs and that technology has had much time to advance since then, shouldn't there be a readily available current or recent production CD-4 spec cart/styli combo at a much cheaper market price than what I see on ebay out there?

If anyone has any relevant ideas, advice, or knowledge to share or knows of a significantly cheaper dealer for these things than ebay please chime in.
Also please correct me if I'm wrong in any way...I'm new here and trying my best to get the hang of things without stepping on peoples toes.

[Jpowell1]

Dont worry so much about stepping on peoples toes
Some people will be offended for various reasons like daring to ask a question that was answered in 2007 and why dont you use the search function you nOOb
I have always thought of the CD-4 format as a dead end and never embraced it
I found an interesting and informative tutorial on quad sound on wiki of all places and it seemed there were compatibility issues which reminded me of the beta vs VHS or HD-DVD vs Blueray but with quad nobody won
When I was (much) younger there were even quad radio stations
There is a bay seller named needledaddy1 who could probably help you
he has helped me on more than one occasion
I think your plan will work just keep digging and educate yourself as best you can
Good luck

[Ohighway]

CD-4 decoder

Suitable cartridge

Low capacitance interconnect cables from turntable to receiver.

[wualta]

You'll probably want to join up at www.quadraphonicquad.com. There are forums devoted to the CD-4 system and CD-4 recordings. Some of their members are also members here (Doug G. being a helpful example).

One thing: You don't absolutely have to have a Shibata stylus. CD-4 recordings have been successfully played with humble little elliptical-stylus, light-tracking cartridges that predate CD-4. What you would like, ideally, is some sort of "line-contact" stylus, of which the Shibata design was one early and famous example. Hyperelliptical, Stereohedron, Paralinear, Fine Line, LAC, MicroLine and Micro-Ridge are all trade names of line-contact styli, and there are many more.

The problem is, the more well-known line-contact styli are either going extinct or becoming very expensive (well above your $50 limit, at least), or both. There are a few ways around this, and here's where you'll want to ask about the cheapest combination of proper new or new-old-stock stylus and cartridge body-- not necessarily ones that were originally sold together-- that will give you reliable CD-4 without messing up your discs, which happily were made to be extra durable, but still.

If you have a local full-service record shop, one with a service department, that would be a good place to hang around too.

[Electronic M]

Originally Posted by Jpowell1

Dont worry so much about stepping on peoples toes
Some people will be offended for various reasons like daring to ask a question that was answered in 2007 and why dont you use the search function you nOOb
I have always thought of the CD-4 format as a dead end and never embraced it

I did search the forums but did not find anything other than a few discussions debating the best equipment and whether or not one could play a CD-4 record with a normal stylus without erasing the sub carriers, buried amongst a bunch of threads of folks bragging about their LP collections...And that was after trying a bunch of different search terms and getting zero results each time...

I'm surprised folks here get bent out of shape over a re-asking of an old question. I've spent a heck of a lot of time on the Videokarma forums(as in read every new post for over a year) that were split off of here years back and I've never seen someone there be even the slightest bit bothered over that....Often times there will be half a dozen similar topics and the same folks that said something useful in one will be happy to try and summarize it better than the last time or give links to relevant threads.

For me the formats that have been abandoned are the height of cool. I restore and use much of the older equipment I own(I collect tube era radios and TVs as well as obsolete recording formats and some audio gear), and in the process of using and maintaining this gear I gain a great appreciation of the skill and ingenuity that went in to their design and construction. It is surprising what quality was achievable before computers were used in engineering work and when most products were still made mostly by hand.

[Doug G.]

I'm afraid your $50 limit will be the stumbling block for you to get CD-4 capability. When I got back into CD-4 a few years ago, I was lucky to find components very inexpensively but it was still over fifty bucks.

You need both a demodulaor and cartridge with CD-4 specs to be successful. Sometimes, I have seen demodulators go for around that money on eBay but, these days, the cost is usually higher. Patience helps, however and you might be able to get one component now and the other later.

Wualta's advice to join at quadraphonicquad is a good one. Post your plight over there and see what happens.

What cartridge(s) do you have now? It's possible that just a stylus replacement will turn one into a CD-4 capable cartridge.

Also, CD-4 records really are NOT harmed by playing them with a regular stereo cartridge. That is an old myth. RCA and JVC did tests back in the day and discovered that the carrier engravings were still there even after many playings with a regular cartridge tracking at 3 grams. It's kind of a psychological thing, however, and waiting until you have a CD-4 cartridge may be kinder to your psyche.

EDIT: Oops, upon rereading your post, I see you say you are limited to $50 for the cartridge, not both pieces, so that helps a bit but that's still pretty low.

Doug

[tcdriver]

Electronic M,

Welcome to AudioKarma. I have used CD-4 records in my quadraphonic system. Others on this forum have also had some success with that format. It is, in my experience, more difficult to set up and obtain good results than with the other quadraphonic record formats (Stereo-4, SQ and QS). At its best, it produces better results than the matrix style formats and is really wonderful to hear. Getting the best out of that system can be a challenge.

What is needed:

1. CD-4 record, (aka Quadradisc) in good condition
2. CD-4 capable phono cartridge capable of 45kHz. reasonably flat frequency response.
3. Turntable / tonearm with low capacitance (usually < 100pF)
4. CD-4 demodulator, either a stand alone unit or built into a preamp, integrated amp or receiver.
5. Four channels of amplification
6. Four speakers.

Careful setup of the cartridge / turntable is a must.

The only way that I can imagine you will be able to get a suitable system for the $50 budget you have set will be to get real lucky. You might be able to find suitable equipment in thrift stores, garage sales, craigslist, or on that well know internet auction website.

You may try reaching out to find someone close by that has such a setup to show you or demonstrate just what system can do.

Good luck.

[Electronic M]

Originally Posted by Doug G.

I'm afraid your $50 limit will be the stumbling block for you to get CD-4 capability. When I got back into CD-4 a few years ago, I was lucky to find components very inexpensively but it was still over fifty bucks.

You need both a demodulaor and cartridge with CD-4 specs to be successful. Sometimes, I have seen demodulators go for around that money on eBay but, these days, the cost is usually higher. Patience helps, however and you might be able to get one component now and the other later.

Wualta's advice to join at quadraphonicquad is a good one. Post your plight over there and see what happens.

What cartridge(s) do you have now? It's possible that just a stylus replacement will turn one into a CD-4 capable cartridge.

Also, CD-4 records really are NOT harmed by playing them with a regular stereo cartridge. That is an old myth. RCA and JVC did tests back in the day and discovered that the carrier engravings were still there even after many playings with a regular cartridge tracking at 3 grams. It's kind of a psychological thing, however, and waiting until you have a CD-4 cartridge may be kinder to your psyche.

EDIT: Oops, upon rereading your post, I see you say you are limited to $50 for the cartridge, not both pieces, so that helps a bit but that's still pretty low.

Doug

Here is as good of info on all 1970s+ vintage phonos in my possession as I can get. Some stuff is not labeled or is installed in such a way that dis-assembly to check for numbers risks causing damage.

The order will be... (player installed in) [cartridge info] (styli info) NOTE:interchangeable cartridge/styli between models represented by **

(Garrard synchro-lab, component type, good) [Pickering V-15/ATE-3] (styli unknown with clip-on brush)
(Garrard synchro-lab,component type, untested) [Shure M71EMB] (styli missing)
**(Akai FD-3,system,good) [cart unknown] (Akai RS-84)
**(Fisher,component,being serviced) [cart unknown] (styli damaged)
(Realistic,component,good) [Realistic R27E] (Shure RS E)
(JVC L-FX22,component, good-) [stanton] (D71EE)
(Technics SL-5) [Shure LT10] (Shure)
(Zenith,console,good) [142-167] (unknown new)

My plan is to go for the cartridge/styli combo first, and then either look for a decoder or dig up some decoder schematics and assess the feasibility of building one from scratch(as in making sure there are no NLA semiconductors or exotic transformers used).

The two RCA CD-4 albums I presently have are not rare or all that desirable, and cost me less than a buck each, so I may toss one on my SL-5 for a listen and see if the unique reflections caused by the sub-carriers remain after the fact(I recall reading elsewhere that they vanish when erased). I'm curious enough now to risk a song or two to find out the truth for my self(no offense but "take everything with a grain of salt" is one of my life policies).

The 50$ spec may have some headroom some time in the future depending on how some variables in some priorities play out.

[KentTeffeteller]

You are also going to need a turntable who's tonearm is happy tracking at 1 1/2 grams without issues and has low capacitance wiring. Your Pickering V 15 or Stanton 500 is not CD-4 capable. In Pickering and Stanton you're looking at XSV or XUV territory or 981 territory and expensive. Your Zenith won't do CD-4. Your Technics SL-5 with the right cartridge can in good order. And in most cases, you are looking at $150 to $300 up for a Shibata stylus. There are line contact options for the Audio-Technica P mounts that your linear tracking arm uses.

[for_p1]

I do not think you will be able to find suitable cartridge/stylus for $50. 45 kHz is reachable by some modern MC type cartridges, but they are on expensive side (usually over $500). As for decoder, look if someone made software for that. If you record output from your LP player on computer at 24/192 , you should have enough resolution for decoding CD-4 signal in software. I know that there are software decoders for SQ/QS, but it is possible there are for CD-4 too.

[KentTeffeteller]

There are no software CD-4 decoders. None! All hardware. SQ/QS is an entirely different system.

[wualta]

Originally Posted by Electronic M

Here is as good of info on all 1970s+ vintage phonos in my possession as I can get...
(Technics SL-5) [Shure LT10] (Shure)

I'm looking at my big list of Shure cartridges and can't find an "LT10". Can you get a closeup photo of this cartridge?

[Electronic M]

Originally Posted by wualta

I'm looking at my big list of Shure cartridges and can't find an "LT10". Can you get a closeup photo of this cartridge?

Ask politely and ye shall usually receive.


Snapped a few more but I'd prefer not to clutter things or go off topic so you can go here to see the rest of the pics if the one above has not sated your curiosity...http://s1095.photobucket.com/albums/...ctronicMemory/
Feel free to PM me with questions or comments about it. Since it seems to not be a quad cart I'd prefer not to discus it in this topic.

[wualta]

Eh? Did you think I would've mentioned it if I didn't think it had a chance to be turned into a quad-capable cart with a stylus swap?

[marcmorin]

Some things to note about what is needed in a cart. Any Grado from the Black and up will play quad. What is overlooked in cart specs is inductance. A high inductance cart body doesn't produce quad well, if at all. The AT quad bodies had inductance figures of around 330mH, where their "normal" bodies were 2-3 times higher than that. Grado carts, like MC carts are very low in inductance.