CD-4 Cartridge Stylus Recommendations

[barfle]

I'm not sure RBCD ever specified how quad was supposed to be formatted on the discs. All I recall is a flag saying the content was quad.

If we'd had MLP back then, quad could have been fitted in roughly the same size as normal albums ultimately were.

Unfortunately, the guy giving the lecture was unaware of the quad era. I talked with him briefly after the lecture, and he knew nothing about MCH vinyl. During the lecture, he expressed confusion as to why anyone would ever want four channels of audio.

Of course, the red book is unavailable to us plebes. When I worked at the patent office, I tried to get my supervisor to spring for a copy, but was turned down.

As a result, my only “formal” knowledge of the format is from that single lecture, maybe a couple of hours.

 

[jaybird100]

Absolutely, but there may possibly be more out of phase signal due to the Quad mix, conversely there might not be, so its hit & miss as to what appears

I disagree. Matrix uses out of phase information to create the surround effect. Discrete doesn't have to do so. There will still be some, in the case of CD-4 records, but it has nothing to do with the quad effect overall. BTW, applying a matrix to the base band signal is the basis of the UD-4 system. It can allow for differing levels of sophistication in the decoding, from a basic matrix, to a logic matrix, to fully discrete. On paper, it looked even better than CD-4. In use, not so much. It never gained acceptance outside of Japan.

 

[Owen Smith]

Unfortunately, the guy giving the lecture was unaware of the quad era. I talked with him briefly after the lecture, and he knew nothing about MCH vinyl. During the lecture, he expressed confusion as to why anyone would ever want four channels of audio.

How can someone giving a lecture about audio be so ill informed?

 

[jaybird100]

I replaced the plain decoder in my QX 646 and QX949 with a full logic QX949a board
in each unit, but preformance outside a test record is minimal.
I should have bought a TateII when they came out, I had the chance and passed.
Non-logic boards don't cut it. IMO

Have you checked out the Surround Master v.3? Its SQ decoding rivals the Tate, and its QS/RM decoding is the best I've heard. Price-wise, it's a serious bargain.

 

[barfle]

How can someone giving a lecture about audio be so ill informed?

It wasn’t actually about audio, it was about recording technology. The depth of the pits being 1/4 of the wavelength of the light beam reading it, eight-to-fourteen modulation, etc. But, yeah, I was surprised that he didn’t know about quad vinyl.

 

[par4ken]

It wasn’t actually about audio, it was about recording technology. The depth of the pits being 1/4 of the wavelength of the light beam reading it, eight-to-fourteen modulation, etc. But, yeah, I was surprised that he didn’t know about quad vinyl.

Not uncommon for "experts" to be experts only in a narrow field. It always surprises me when a learned person is unaware of "simple" things that I've known about even as a child.

 

[Doug G.]

Where were those cartridge/stylus recommendations, again?



Doug

 

[par4ken]

Where were those cartridge/stylus recommendations, again?



Doug

Most are away back in post "1

 

[par4ken]

Getting more on track this article by Len Feldman from the February 1974 issue of Radio Electronics is rather interesting. It brings up a few important points. My summarization follows.

Sometimes you can even get away without using low capacitance cables! Rolloff of the high end carrier is dependant on the impedance (inductance and resistance) of the cartridge as well as cable capacitance. My (my own experience not from the article) Grado Superfluxbridger was supposed to be non critical in CD-4 application due to its low inductance. Low inductance will result in less rolloff with higher capacitance loads. On the other hand it provided a lower output voltage to begin with than some other brands. As long as the demodulator gets enough signal we should be OK.

Higher output cartridges may tend to work better because they can tolerate more rolloff.

Mention was made of proper alignment (overhang, vertical alignment, anti-skating etc) as being critical. Those adjustments may make little audible difference with plain old stereo listening but are a must for CD-4!

I have always admired Len Feldman's writing. Despite be a co-developer of the EV-4 matix system he never touted it as being the best nor did he ever trash talk any of its competitors. He always wrote clear and fair reports, always upbeat emphasising all the positives of each even downplaying any negatives. One of Quads great unsung heros!

 

[par4ken]

Billboard was calling it Quadrasonic but Radio Electronics used the term Quadriphonic.

This from June 1974 Radio Electronics

QUADRAPHONIC IS ILLITERATE!
IHF SAYS "USE QUADRIPHONIC."
Proper English usage wins. For more than a year. Radio -Electronics has
been using the term quadriphonic to
describe 4 -channel sound systems and
equipment. Now the IHF (Institute of
High -Fidelity) has announced that
quad -/phonic is indeed the proper
word. and the all too common
quadraphonic is verboten.
The prefix quadra is not a prefix at
all. It is not Latin, not Greek. not English, but garbage. Radio -Electronics
has been using quadriphonic wherever
possible. But this has not been easy. If a manufacturer decides to identify his
product as a quadraphonic unit, we must use this same name in identification. However, we will continue to use quadriphonic except in places where we are reprinting a manufacturer's name.

Edit: I posted in the wrong thread it should go here.
https://www.quadraphonicquad.com/fo...spelling-and-pronunciation-guide.32643/page-2

 

[Owen Smith]

Billboard was calling it Quadrasonic but Radio Electronics used the term Quadriphonic.

The Oxford English Dictionary is descriptive ie it describes the English language as it is used or ever was used. If people start using a word it goes into the OED with that meaning, so that in hundreds of years time scholars will be able to understand what was being said. There is no formal definition of what is and what is not valid English, at least in British English.

This is in contrast to French where the Academie Francais dictates (or attempts to) what is valid French and what is not. As such the official definition of French frequently diverges from common day to day usage.

 

[jaybird100]

Billboard was calling it Quadrasonic but Radio Electronics used the term Quadriphonic.

This from June 1974 Radio Electronics

QUADRAPHONIC IS ILLITERATE!
IHF SAYS "USE QUADRIPHONIC."
Proper English usage wins. For more than a year. Radio -Electronics has
been using the term quadriphonic to
describe 4 -channel sound systems and
equipment. Now the IHF (Institute of
High -Fidelity) has announced that
quad -/phonic is indeed the proper
word. and the all too common
quadraphonic is verboten.
The prefix quadra is not a prefix at
all. It is not Latin, not Greek. not English, but garbage. Radio -Electronics
has been using quadriphonic wherever
possible. But this has not been easy. If a manufacturer decides to identify his
product as a quadraphonic unit, we must use this same name in identification. However, we will continue to use quadriphonic except in places where we are reprinting a manufacturer's name.

Edit: I posted in the wrong thread it should go here.
https://www.quadraphonicquad.com/forums/threads/quadraphonicquad-spelling

To-MAY-to, to-MAH-to...

 

[Doug G.]

We quadraphiles created our own prefix, so THERE! We will not be subject to dictatorial, antiquated, language rules.

Doug

 

[Stiffgriff]

I see the AT-VM95ML is not on this list. I was told it was CD-4 capable.. is it not? I’ve been having trouble with my Marantz CD-400B demodulator and getting the radar light to light up when playing CD-4 records. Thanks!

 

[Quad D]

I see the AT-VM95ML is not on this list. I was told it was CD-4 capable.. is it not? I’ve been having trouble with my Marantz CD-400B demodulator and getting the radar light to light up when playing CD-4 records. Thanks!

I am sure it is CD-4 capable, since VM95SH I am using is very capable. You still need turntable with reasonably low inductance cables, though.

 

[Stiffgriff]

I am sure it is CD-4 capable, since VM95SH I am using is very capable. You still need turntable with reasonably low inductance cables, though.

Interesting. I’m using a Marantz 6200 which I think should have the right inductance cables since it’s a vintage turntable of the time. Maybe I something wrong with the CD-400B demodulator

 

[jaybird100]

I see the AT-VM95ML is not on this list. I was told it was CD-4 capable.. is it not? I’ve been having trouble with my Marantz CD-400B demodulator and getting the radar light to light up when playing CD-4 records. Thanks!

I use the AT-VM95SH, which does CD-4 quite well. I've heard, though never tried, that the ML version does, as well.

 

[Tim7099]

I see the AT-VM95ML is not on this list. I was told it was CD-4 capable.. is it not? I’ve been having trouble with my Marantz CD-400B demodulator and getting the radar light to light up when playing CD-4 records. Thanks!

It works well in my set up!

 

[MidiMagic]

Interesting. I’m using a Marantz 6200 which I think should have the right inductance cables since it’s a vintage turntable of the time. Maybe I something wrong with the CD-400B demodulator

Actually, until 1973, most turntables were sold with standard high capacitance cables. You had to buy and install the low capacitance cables yourself.

 

[Doug G.]

Capacitance is the issue with cables from the turntable to the demodulator. And, never assume. Be sure. Follow the CD-4 rules or you are likely to be disappointed.

Doug