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

[RenoKen]

Give me a Paypal account or an address to send a personal check and I'm in. I have a collection of CD-4 records as well as a lot of SQ/QS and would like a proven cleaning system. I would prefer the most direct way possible so you don't have to give a cut to some transaction processor. Hoping to be ready to enjoy my treasures more this summer (I teach high school in my second career and don't have much relaxation time for about nine months). Also want to be in line for one of the new Demodulators.
Thanks.
Ken

 

[rolvkarsten]

Hello Quadraphony Community,

I gave had numerous requests and questions about the record cleaner that we developed for CD-4 records. It turns out that this cleaner works wonder on all disks including vinyl, acetate, and shellac. Yes, indeed, I have the original formula, so I looked into have a small production run made for anyone who wants to clean their disk library. The results were positive, so I am having the run made. I also had the original bottle artwork, so the bottles will have the original label, "QSI Record Cleaner...For Superior Sound".

This is a cleaning kit that will come with an 8 ounce bottle of cleaner and a box of laboratory grade, lint free Kim Wipes for application. In addition will be an application note on cleaning CD-4 records and how to use the cleaner in disk restoration (mono and stereo) before recording. I have had very good results in restoring very badly damaged disks in the restoration process.

One more thing, when the new CD-4 demodulator is available, each one will come with a cleaner kit along with the CD-4 cartridge and of course the demodulator.

I will set up the kit on Ebay and post the item number in a future post. The last thing is the cost. It will be $28.00, which includes shipping. I want every one to know, as with the new CD-4 demodulator, this price covers the costs and is not intended to make profit. Also, I did discuss this offer with Jon to clear posting it here.

That is it for now,

Lou Dorren

USD 28, Lou? Is that a typo? Or is it just the cleaner kit?

 

[loudorren]

Hello rolvkarsten,

Just for the cleaning kit. Demodulator price has not been determined yet.

Lou Dorren

 

[rolvkarsten]

Hello Lou
I thought so!
Just wanted to clarify this, so that people would not come later and expect you to sell it for $ 28!

Rolv-Karsten

 

[ress4278]

Hello rolvkarsten,

Just for the cleaning kit. Demodulator price has not been determined yet.

Lou Dorren

Lou is there any reason NOT to use the cleaning fluid I use on regular stereo vinyl on CD-4 vinyl? It is 80% distilled water, 20% alcohol (91%), and a tiny bit of Photo Fluid.
Thanks

 

[loudorren]

Hello ress4278,

I do not recommend any liquid that contains alcohol for cleaning phono disks. The problem is that alcohol hardens the surface reducing the natural pliability of the surface. This can lead to surface micro cracks and can increase the surface noise of the disk. Some disk compounds contain an anti-static surface which also acts as a lubricant. Alcohol dissolves this off the disk surface increasing the susceptibility to stylus damage and dirt attraction. Needless to say, there is no alcohol in the QSI formula.

Lou Dorren

 

[The Quadfather]

I was mainly referring to after all the quaddies on this website get their demods, then the extra ones might could be sold over the net. The more sold, the merrier. It might make it easier to find one 20 years down the road, if for some reason, one needs to replace one. Quadradiscs are bought and sold every day over ebay, some of those buyers might want a new demod.

 

[bming]

I hope this new demodulator is DC powered by an external low volt transformer (uisng a standard AC low volt input plug) - so that it can be easily sold into any country. Australia being 240V/50Hz. This would be a simple way to make it internationally comaptable. I have not read every post on this subject (there sure is a lot of them indicating a lot of interest out there) so I do not know if the subject has been broached. I thought I just mention it to ensure the rest of the world is not forgotten.

 

[proufo]

I was mainly referring to after all the quaddies on this website get their demods, then the extra ones might could be sold over the net. The more sold, the merrier. It might make it easier to find one 20 years down the road, if for some reason, one needs to replace one. Quadradiscs are bought and sold every day over ebay, some of those buyers might want a new demod.

There's a downside, all the buyers might go crazy getting all the CD-4 records that they were not in a hurry to get.

Get ready for new entries in the Shocker Log

 

[The Quadfather]

Oh God! Wall warts, I hate wall warts! Better, a multitap transformer in a built in power supply. I hope it isn't a wall wart, but it probably will be, since the unit will be small, according to Mr. Dorren. I just hope that isn't the case. Wall warts are usually very poor quality power supplies, electrically noisy and are prone to wasting power and catching fire.

The Quadfather

P.S. Proufo, you may have a point there.

 

[loudorren]

Hello QQs,

brning, Quadfather,

In a previous post answering Quatro-Action, the power supply is a built in universal which will work from 100 to 240 VAC at 50 or 60 Hz. No wall warts.

Lou Dorren

 

[Quadro-Action]

Yes, I hope also for an excellent power supply - not like for excample the tetrasound with its "leisurely" hum. I think, the important over all quality of the new demodulator needs of course also the same quaylity by the power supply. Also DVD players etc. are small in hinsight of high and have very well power supplies. I would pay for such well installation also a some higher price.

Dietrich

 

[Quadro-Action]

Lou, thanks for your quick answer. With your message we can now further on and relaxed look forward till the "sweet" machine will be available.

Dietrich

 

[The Quadfather]

Hey Lou:
Sorry I doubted you, I should have known better. My bad.

The Quadfather

 

[Bonzodog]

Will it have a removable AC cord with an IEC connector, rather than a captive AC cord, to make it easier for our European friends?

 

[kfbkfb]

Regarding Discrete Surround Sound Channel Separation
and Listening Room Acoustics:

In the 1973-11,12 issue of Recording Engineer/Producer:
"Tom Nishida, resident engineer at the JVC Cutting
Center, Inc., Hollywood, has told us that CD-4 currently
provides 20dB of separation in all directions..."

Some current phono cartridges (not CD-4 approved) offer
30+db at 1kHz and nearly 20dB at 10kHz L,R separation.

The new CD-4 demodulator is expected to offer 30-35dB
F,B separation (from a previous post).

(Blu-ray Disc) Dolby TrueHD can be configured to offer
over 100dB of channel separation.

Considering the acoustics of a listening room (with 4
speakers in a square arrangement), what's the point of
diminishing returns for channel separation (40dB, 70dB,
100dB etc.)?

Kirk Bayne

 

[loudorren]

Hello Quad Fans,

bonzodog,

You hit it write on target. Makes power cord changes easy!

kfbkfb,

Kirk, The more separation the better the reproduction, 20dB means the crosstalk is 100 times lower in level than the wanted signal, 30dB is 1000 times lower, 40 dB is 10,000 times lower, 50dB is 100,000 times lower, 60 dB 1,000,000 times lower etc. 30 dB starts to be the point of diminishing returns with regards to separation, however, the crosstalk manifests as dynamic distortion. So as far as overall performance the better the separation (lower the crosstalk) the lower the dynamic distortion. In the early days of stereo it was determined that 29.7 dB was the separation value where the wanted signal level would mask the crosstalk, audibly hiding the distortion. The way to hear the crosstalk distortion in any multichannel audio system is to play a signal meant for only one channel. While this is playing turn down the volume on the active channel and listen to the non active channels. You may have to increase the audio levels to hear the crosstalk depending on the channel separation of the system.

Lou Dorren

 

[winopener]

35dB is related to the vinyl media... no way to go further than that with the Westrex 45 scheme. That's why i prefer to restore from tapes.
Everything else is full separation: cassette tape, 8 tracks, reel 2 reel, cd, dvd... unless they are polluted with a matrix, such as Dolby Surround, CS etc, in order to squash 4/5/6 channel into 2.

 

[The Quadfather]

Hey Lou:
I have a question and you may know the answer. Recently a flood of stylii have surfaced for legacy CD-4 carts. I have already ordered my AT14S stylus. This one I couldn't get for years. I have a cartridge that I did not regard highly because it came from a cheap turntable. But today upon closer examination, I noticed that it's a Matsushita EPC-451C, and upon looking it up, I found that it is a semiconductor type cart that will work with my Technics SH400. Assuming that the cartridge works, would it be worth buying a stylus for it (about $40.00)? I mean, is it generally a good cart? I have never used one of these and have no idea how it compares to say a AT440MLa or a AT14S for CD-4 playback.

The Quadfather

P.S. If anyone else is familiar with this cart, I would like to know your opinion also.

 

[loudorren]

Hello Quadrafolks,

winopener, The Westrex head had its limitations, however both Neumann and Ortofon had some experimental cutter heads that made over 45 dB separation in acetate dubs, lacquer masters and production vinyl.

Quadfather, The EPC-451C is one of the best pickup cartridges I have ever tested. Besides being probably the best CD-4 cartridge price performance wise, it has the feature of not being a generator pickup. It is a strain gauge type which has a DC bias applied and is a variable resistance. This makes a low impedance device which improves high frequency response and left to right separation at high frequencies (>45 KHz). I have 3 of these and 2 450c versions. I would recommend buying several replacement stylus. By the way the new demodulator will support these cartridges. My opinion is that the EPC450C and EPC451C way out perform the AT440MLa and the AT14S.

Lou Dorren