Hello Quad Folks,
Quadro-Action,
Dietrich, There will be 2 analog displays for carrier level, but no VU meters, Sorry. The power supply is universal for 100,105,110,115,117,120,200,205,210,220,230,240 VAC 50-60 Hz.
malcom2010, Good idea, I will try!
electrolad, OK and welcome aboard!
kfbkfb,
Kirk, I read the drivel that Skip Pizzi wrote and ground my molars during the exercise. Giving somebody a great deal of misinformation and a forum to expound such, often leads the non technical reader down the primrose path. This happens far to much in the consumer technologies. His paper was so full of technical iinaccuracies, that I was preparing a definitive answer. Then I noticed that the paper was written in January of 2005 which gave me some relief. None the less, here are some choice examples of bad information.
1. "while a difference signal (i.e., audio not common to both L and R channels) was multiplexed into the FM channel as a 38 kHz AM sub-carrier". Incorrect! The sub-carrier is a Double Sideband Suppressed Carrier Amplitude Modulation (DSBSCAM) This is not AM!
2. "Music was released in a single LP format, the so-called 45/45 stereo system, where vertical groove modulation represented the L+R sum, and lateral modulation represented the L-R stereo difference signal." Bovine fecal mater!!! 45/45 is orthogonal undulation which results in vertical groove undulation L-R (Not L+R) and lateral grove undulation L+R (not L-R).
3. "There have been numerous attempts to move FM beyond stereo in the years since, but none have been successful." Not true. My system was technically successful and was chosen as the national standard for Quadraphonic FM single station broadcasting and the standards in FCC rules 73.319, 73.322, and 73.323 cover the use of my system. It is true that Quadraphonics in general was not a commercial success.
4.Part of this is by design, with the primary purveyor of "matrixed" surround, Dolby Labs, preferring not to license its decoders to FM receivers, due to concern that poor performance under multi-path reception conditions would reflect badly on the surround format's reputation. Absolute garbage! Dolby's concern was that the "matrix" system had so much out of phase information that the mono compatibility was adversely affected. Multi-path had nothing to do with it.
5."One advantage of the matrixed surround system is its ability to reproduce relatively strong, stable and consistent surround images via four channels of audio, while only requiring two audio channels for storage or transmission (thus the "4-2-4" terminology applied to such systems). This is particularly true of matrixed surround systems that feature enhanced "steering logic" circuitry in decoders, such as Dolby Pro Logic. " Technical folly. Let me restate from post 291:
"Wait a minute, what about , Tate, Prologic etc.? Well these devices have an interesting effect. When the Information Theorem is satisfied, they can do something that appears to be correct. When the Information Theorem is not satisfied, they become quite confused. There are 2 conditions in matrix 4-2-4 where the Information theorem is satisfied. Condition number 1 is sending only 1 of the 4 channels at a time. The example is LF only with LB,RF,RB silent. In this case the Tate, Prologic,etc processors have enough information to turn the level down on LB,RF,RB and leave the level up on LF. If only one channel is sent at a time, the sound can be made to appear going around the room. Quadraphonic right? No, it is only a special effect! The minute there are more then 2 audio channels being sent, all bets are off. By the way, when all 4 channels are input on a 4-2-4 matrix system, there will be at least 1 pair of channels on the output that will have no more than 3dB of separation."
6. "Matrixed surround systems use quadrature encoding of front/rear difference information onto the stereo signal, which provides another layer of backward compatibility to audio signals, allowing a single mix to produce acceptable results in surround, stereo or mono listening - again, assuming the creative-stage mixing follows appropriate rules." Technically and empirically unrealizable! An AM carrier and it's baseband may be quadratured to provide 2 independent carriers on the same frequency, however audio frequencies can not be quadratured for independence. Again quoting from post 291:
"The information theorem is one of my favorite discussion subjects. It states that for a given number of input channels, there must be the same number of transmission channels, to reproduce to the same of output channels. This is then defined by 3 numbers. Take Discrete Quad for example. It is defined as 4-4-4, 4 input channels, 4 transmission channels, 4 output channels. It fulfills the Information Theorem perfectly. Now what about any of the matrix systems. These systems have 4 input channels, 2 transmission channels, and four output channels. They fail the Information
Theorem even with all the processors. This is because the 4-2-4 systems are all 2 channel stereo with 4 inputs and 4 speakers.
Here is an analog that should demonstrate what a matrix 4-2-4 system does. Imagine four soda glasses, each one half filled with a different soda. Glass 1 has orange soda, glass 2 has root beer, glass 3 has cherry soda and glass 4 has lemon soda. These are the 4 input channels with the color of the soda equivalent to the phase shift. Now imagine 2 empty glasses representing the 2 transmission channels. Now take input glass1 and input glass2 and empty the contents into transmission channel glass 1. Then take input glass3 and input glass4 and empty these contents into transmission channel glass 2.
Now here is the problem, having poured the orange and the root beer into the same glass, regardless of color, how do you separate them back into their original discrete soda form? The answer is you can not!! All the 4-2-4 matrix systems do is to mix (add) 2 signals on the left together and put them on the left channel and they do the same for the right channel. Phase shifting at audio frequencies serves no purpose unless you are using it as a "guitar effect"."
Lucanu, I will look into it.
jrborg, Glad to have you aboard. If you have to do that much to eliminate turntable rumble, I would look for a flaw in the turntable. Most good direct drive turntables like the Technics SL-1100 or SL1200 have almost unmeasurable rumble. As far a Bass directionality is concerned, this was proven and confirmed during the National Quadraphonic Radio Committee double blind directionality tests.
Lou Dorren
