Lou Dorren: A new CD-4 Demodulator!!! [ARCHIVE]

[The Quadfather]

My experience would suggest that yes, they will give trouble while we are still alive. Some of us, at least.
The Quadfather

 

[loudorren]

Hello CD-4 QQs,

It appears that I am not the only one who is alive and kicking! Let me see if I can answer all of your concerns.

proufo,

Yes the caps are large and are of great quality. However that is only good parts selection. The system has a large number of voltage regulators to first supply the correct voltages and also to isolate noise in and out of each section. Also with regard to the phono pre-amplifiers, they are fed with a special power supply system. Most 3 terminal voltage regulators have a noise floor of -100dB. This value does not include the 1/f low frequency noise. Because the phono pre-amplifiers involve RIAA eq, -100 dB is not enough to suppress low frequency system noise.

In this new demodulator , the power supply voltages come from inverting noise cancellation filter systems on both the plus and minus supplies. This give a noise floor to the pre-amplifiers of -149 dB. The amplifiers that I have chosen for this project are the lowest distortion, lowest noise, highest common power supply noise ratio that are available.

krkier,

The amplifiers that I have designed in to the demodulator are speced at +- 22 Vdc (44 Vdc total). The limiter is a Philips SA606 which was chosen for its 85 dB RSSI system which drives the front panel meters.
Every body that is worried about the SA571 don't be. There are six manufactures of the part, however I am using a specially selected version from ON. It is a modernized version of the original Signetics part. ON has no end of life for this part!

To every one,

I am going to also offer a critical components kit which will have all the parts you need for repair.

Any more questions, please post.

TTFN

Lou Dorren

 

[proufo]

It appears that I am not the only one who is alive and kicking! Let me see if I can answer all of your concerns.

Many thanks, Lou!

 

[quattro64]

Lou,
Welcome Back! Hope you're feeling well! There was some discussion about this phono having a flat setting for those who might want to use computer software for EQ. Is that a part of the final design? Just Curious, not a big deal.

Q

 

[loudorren]

Hello quattro64,
Thanks for the kind words. The new demodulator has a line input which has flat eq. This was requested by QQ members during the design phase.

Lou Dorren

 

[jrlinks]

Happy 5th anniversary!
And thank you Lou for sticking with this project for us quad freaks.

 

[Dave Cawley]

Guys

Inspired by the mention of this in January 2013 Hi Fi World by Martin Pope, I really want one!

If there are manufacturing problems of any sort I would be willing to help. And or finance the rest of the project with royalties going to Lou ?

Or something I haven't thought of ?

Regards

Dave

 

[JonUrban]

Hi Dave,

The project is a personal project of Lou's that he's doing in his free time. I have not heard from him lately, but I would imagine with the CES last week, he's been pretty busy with his real job!

Stay tuned

 

[Dave Cawley]

OK, but I'm here to help !

Dave

 

[maspadaro]

Hi everyone, is there any update on the demodulator? I put myself down for 1 and I am sure Lou or Theresa will contact us again to make sure the tally of requests are still active, but its feeling like as time goes on the probability of this project being realized is becoming smaller. Sorry the analyst in me is reacting.
Regards,
maspadaro

 

[jrlinks]

Like many of us you have probably read every post on this subject here
so you know that the answer is... no one knows except Lou and he's been
"busy" with other things (plus some health issues) and does not communicate often.
It's been 5+ years since the initial announcement and 5 months since we have heard
anything from him.

My choice has been to acquire one or 2 working vintage demods,
keep buying CD-4 lps while they still exist and...get on with life.
If Lou's unit ever is finished and sold, it will be a pleasant surprise,
but don't bet on it happening.

 

[The Quadfather]

Yep, Jrlinks, that sounds like good advice. My 4DD5 is sounding pretty good and I have a spare unit. Besides, I can't afford the Dorren demod anymore. Artificially high gas,food, and electric prices are eating me up. Especially gasoline. I'll be happy to hang on to what I have.

 

[aludra]

I still want my Dorren Demod plus stylus and I believe Lou will come thru and will totally be worth the wait!! Thanks Lou and JON for all your trouble!
Mike

 

[proufo]

Maybe Mr. Dorren would be willing to work with the Surround Master team in bringing this product to reality, even if it would cost somewhat more.

The SM team seems to be capable in bringing products to market.

 

[The Quadfather]

I'm not saying I don't want one. I probably will buy one if and when they come availlable, but it will be hard to do.

 

[quadjoe]

I definitely will buy one when they become available. I set the money aside a few years ago, and I haven't touched it. I'm a very patient person, so whenever Lou gets to a point where it can be made and sold, I'll be on board.

 

[maspadaro]

Hope is eternal they say.
If and when this occurs I would get it for the modern Pioneers systems and not my vintage ones. I also have spared CD-4 modulators, so I am not in desperate need, but to be truthful a project like this should be taken over by a start up financing and get funded correctly to refocus on it. As it stands now it would be very hard and for Lou alone to continue this. There is only his wanting (love) to do this that has kept it going. If we really want this, we should start funding it and not just pledges to buy. There could be a market for this, I see some TT worth 15K, God know a modulator system that will allow you to play sorround would be worh something as a patent at least. Not to mention that companies might start rereleasing or making new music for sorround. Well its a dream.
Regards,

 

[leevitalone1]

Hope is eternal they say.
If and when this occurs I would get it for the modern Pioneers systems and not my vintage ones. I also have spared CD-4 modulators, so I am not in desperate need, but to be truthful a project like this should be taken over by a start up financing and get funded correctly to refocus on it. As it stands now it would be very hard and for Lou alone to continue this. There is only his wanting (love) to do this that has kept it going. If we really want this, we should start funding it and not just pledges to buy. There could be a market for this, I see some TT worth 15K, God know a modulator system that will allow you to play sorround would be worh something as a patent at least. Not to mention that companies might start rereleasing or making new music for sorround. Well its a dream.
Regards,

Bless your little heart for having a good out look, As far as record companies making more quad, it's not ever going to happen. We can't get them to do high rez mc. The neg. attitude that Donald Fagen took with his last work, was the blow that hurt-he was supportive and made some of the best MC HR stuff! Morph, the "surround album of the year" and the little ******* puts out "Condo's" in stereo, because most people use pc speakers to lisetn anyway" that attitude alone is a buzz killer. Effin little ****! Well, I never listen to music on pc speakers! what a waste !! At least they should have it done in 5.1 for those who want it. All music should allow the opportunity to have a choice! It could be offered in a DL to aviod waste of money in production of physical media that may not sell. I see SC on HD tracks in HR-where I got my copy-so the method is viable!! C-S'krs!!

 

[maspadaro]

Companies follow money, they don’t do it at the present time because they don’t see the money in it but it doesn’t mean the money might not be there. I was using the example of a 15k Turntable. Who would buy a 15K turntable?? I mean really, that means you need a 20-50k system. Did you see how much a cart/needle can go up to, thousands of dollars?
The idea is not farfetched. We are on this website for a reason, which means there is a need/want. It just needs to be monetized and then the companies would flock to it. The problem is to figure out how to monetize it and make it relevant. I am not sure if you noticed but tapes are not going to make a comeback, unless there is something better about them that people can appreciate.
Vinyl is the purest recording; there are no 101010100 just the audio that came from the artist. Granted even these recording weren’t perfect and were run through filters, everything is a filter, but it was close to what they sounded like. It doesn’t mean it will get picked up, it just means that there is a niche which could bring about changes in thinking. There is some technology that people can relate to and then there is transient technology which is just that, it takes you to the next step and that is all (tapes).
Even though all technology is transient, some are a different in the sense that they change the medium. Vinyl brought entertainment to everyone, like radio and TV. They all have lasted a long time, why because they were the purest of the form of how humans interacted and created a change. Blu-Ray is the opposite. What did it bring, not much of a change from DVDs unless you have the best room/size and best equipment ($$) the added bonus is lost. Tape was not as bad; it brought portability which was missing from owning vinyl but lost sound. Discs are doomed since MP3 came to being, but only after memory was cheap to buy and people started to move away from 128 to higher quality songs , lossless.
Sorry didn’t want to go into a tangent

Decoder/demodulators..etc are still sold, new and old so yes I am a bit optimistic, but then a lot of companies create and sell a lot of cr*p so why can’t Lou create a better version of a cd4 demodulator and sell it to big companies. Yes it might be sold as a novelty, but there is lots of money in vinyl just look at the prices of modern turntables/carts/needles

Now the questions that beg to be asked are, has the CD4 demodulator been taken to its technical hardware limit since it needs to encompass old technology and because the number of recordings is limited? Is there a big enough base to jumpstart it?
What do Quad vinyls bring to the table that other technology does not? Maybe cd4 has always been a transient technology and it will die as blu-ray will..
Ohh righty then, that is all for me.

 

[ndiamone]

Companies follow money, they don’t do it at the present time because they don’t see the money in it but it doesn’t mean the money might not be there.

Unless you're talking about the same people we are - the audiophiles and their capitalist relatives who don't CARE if a project is going to bring in any money or not.

Just like the vast majority of book, record and antique dealers, most of which at least in my experience got their money elsewhere and just have the shop to have something to do in their retirement - and to have a tax write off.

The idea is not farfetched. We are on this website for a reason, which means there is a need/want. It just needs to be monetized and then the companies would flock to it. The problem is to figure out how to monetize it and make it relevant.

Hopefully by some of the same people that patronize and subsidize the arts, fund the Smithsonian and Library of Congress, or support the research on old media being done by Carl Haber et al at the Lawrence Berkeley National Labs.

...because the number of recordings is limited?

Not if we have something to say about it.

Combination CD-4 45LP and DMM.

We posted this on the Lathe Troll forum as well since it has to do with cutting, but basically we think the only way CD-4 would make even a LITTLE bit of a comeback is if we coupled it with DMM technology and cut it at 33 for 45 playback.

My colleagues and I have been researching this for about the past seven years or so - and we think either with one of the latter-day (1977) 2/3rd speed CD-4 cutterheads Greg Bogantz worked with - or the Ortofon prototype they made exactly six of in Scandanavia in 1979 -

we could have them converted to DMM -

get a VMS-82/84 lathe and in the process become the only commercial mastering house in America (besides Scientology) to even HAVE DMM in the FIRST place even for NORMAL cutting (which could also help raise money for the CD-4 DMM project) - and then

Attract the NON-CD-4 audiophile market as well with cutting at 33 to play back at 45 WITHOUT CD-4 the same way that both covers A) the same guys that would buy Half-Speed-Masters (if they made them) as well as the guys who bought B) the Super-Sonic 45-RPM formats that split a single LP over 4 sides - and then once we did that for awhile - do the same thing WITH the CD-4.

But with DMM we wouldn't HAVE to split it up over two discs, so then it would keep the cost down to a reasonable amount since DMM can give you a side length of up to 35 mins for 33 without MUCH loss of quality - at least for which the 45 RPM speed wouldn't make up in one fashion or the next - which means roughly 23 minutes at 45 - enough time for the vast majority of single-disc LP's.

The reason we think the Ortofon head would be the better choice of the two if we could get the tech drawings and all the final engineering designs - is because the Ortofon half-speed-masters on LACQUER in the 70's were so much clearer sounding than those made on either the Westrex or Neumann - partly because the bass contour effect - while there - is about half that of the Neumann or Westrex heads - at least according to a handful of engineering testimonials we found.

AND the 2/3rds cutting speed that was already proven successful in 1977 before CD-4 died, (in this case pushed up slightly from 66.6666% to 75% speed) eliminates or greatly minimizes the bass contour effect inherent in half-speed mastering. Or so the various whitepapers quote from guys who supposedly had ears enough back then to know what were they talking about.

Check out the MFSL Dutch Half-Speed vs the Mobile Fidelity Half-Speed of Days of Future Passed to get a good example - or just about any decent title that had double-inventory between MFSL, CBS Half-Speed and Nautilus. Most Mo-Fi's were cut on an Ortofon and most Nautilus and CBS HSM's were cut on a Neumann.

After re-setting the NAB and RIAA curves - if you play back a 15 IPS master on a MUZAK machine (that we already have in an all-tube 350AG) at 11-1/4 IPS - we cut at 33 for 45 playback to avoid having to use more non-standard equipment than we have to and waste money.

The speed percentage (74.0740740... and 75.00) is not that much different than the speed difference between US 45's (45.00) and 78's (78.26) and those made in 50Hz/220V countries which are 45.45 and 77.92. Which if guys thought there was that big of a difference, since presumably they'd all be on audiophile turntables with pitch adjust anyway - we could put a strobe around the edge of the label with the exact speed - and then have the first disc be full of test tones and generic music that we give away.

And then the Seeburg background-music jukebox people we know want to use DMM to re-cut all the Seeburg, Rowe (CustoMusic) and AEI 16-RPM nine-inch discs with the two-inch-hole - and the 7-inch 16-RPM Chrysler Highway Hi-Fi, and the Auto-Com 16 RPM flexidiscs and on and on and on people - all of whom want it pressed onto colored vinyl that matches the original label color - that they all need for their specialized custom players that they keep running 30 years after the format was withdrawn - like the 78 RPM re-issues Len cut for Rhino back in the 90's for ``jukebox use'' even though nobody with a brain actually used `em thereon.

And we also found out that even though the DMM mechanical chatter is around 30KHz - which means even if you COULD cut CD-4 in real-time on DMM - the chatter would wreak havoc with the carrier wave - but again - the law of mathematics supposedly comes to our aid here as well because according to our various math geniuses - the 30KHz chatter would still be at the same 30KHz when mastering at 33 for 45 playback as it would be for 33 for 33 playback.

Meaning your 30KHz mechanical DMM chatter would not only NOW be 45KHz but it would also be DOWN 10 or 20 dB as well compared to 33 for 33 playback - and the 30 KHz CD-4 tone being recorded would now be 22-1/2KHz - supposedly well out of the way of one another.

So there IS a market for it - we just need more than one sponsor - and we need to get all the sponsors all on the same page to

get the DMM lathe in the first place -

get the drawings to the Ortofon head -

pay Len Horowitz or Flo or whoever to re-design it to match or exceed the six prototype heads from 1979 -

do the same for the Quadulator -

pay a couple of the few remaining DMM engineers in the world
to come work with the few remaining CD-4 engineers in the world
to come work with the few remaining half-speed-master guys

and then go ``on the air'' and understand that we'd be using the thousands-of-sides from the CustoMusic etc libraries as training grounds to A) raise money and B) get a good handle on the process, tweaking as we go before we start doing the DMM 33-for-playback-at-45 records WITHOUT the CD-4 - and then progressing to the same thing WITH the CD-4.

So like I said - if anybody can help with sourcing equipment, documentation or sponsorships and is serious about wanting to sponsor some new DMM/CD-4/45-LP technology - drop us a line.

Because if we do it on our own first - as a noncommercial venture - then maybe it - as well as Lou's work - can both become commercial once again.

Oh, and for a turntable, we'd need to resurrenct this old Denon linear tracking prototype they made in Japan in the mid 80's that is not only linear tracking, but it also has a movable center spindle to correct for eccentricities in the disc AND is has some sort of ``eyes'' in the lid so that - instead of playing constant ``catch-up'' like a normal linear tracker (fall behind in the groove and have a servo drive spin a bit to catch it back up) this one had a Groove Mapper in it which would spin the disc a few times after being centered and capture an image of the groove pack and then relay that information to the tonearm servos so that it would follow the pack exactly.

It didn't work in the 80's because computing technology wasn't up to the task - but with today's binocular high resolution image-capture devices - it should be a breeze.

Or if we wanted - in order to get more than 22 minutes on a side - while we're bringing back extinct technologies - we were looking at bringing back the sixteen-inch LP mastered onto a 17-1/4 inch blank.

For which we already have a company in Northern California who says they can make the DMM blanks up to 18 inches across and 200 microns deep if we want.

We also have a source for two Hamilton presses that have a 24 inch throat, and Erika Records says they could get an 18 inch blank into their plating tanks no problem.

So we see where it all goes.