Al and Agisthos are right. I was not asking the content of the message (signal). I was asking for a physical description of the signal. I thought I was asking in effect for someone to dispel a myth. Now I'm not sure of that because there seems to be a gray area of confusion depending on what exactly is the question. I also read that a digital coax cable between transport and DAC should be 5 ft long. This certainly qualifies as myth. Lynne |
Hi Lynne, Perhaps surprisingly, the 5 ft/1.5 meter length suggestion is not a myth. See Steve's paper here, which makes sense to me, and is also supported by experimental results that have been reported by some A'gon members I consider to be credible. What length will be optimal in a given system is dependent on a number of hardware-specific variables, however, which are generally unspecified, and IMO that recommendation should be viewed as a length that is LIKELY to be optimal in MOST cases, but is not guaranteed to be. There have been at least a few reports I have seen here from members who have compared different lengths, and have found shorter lengths, such as 1 meter, to be preferable in their systems. Also, if a very short length is practicable, such as 8 inches or less, IMO that stands a very good chance of being an optimal choice. Some further comments on the definitions Steve provided in his post above: As I indicated in my previous post, what he defined as "1's and 0's" has nothing to do with the 1's and 0's which comprise the data content of the signal. A less ambiguous way of referring to what he defined as "1's and 0's" would be to refer to them as "logic levels," or more specifically as "logic 1" and "logic 0" levels, respectively. If we go by the assumptions I stated in my initial post, that "1's and 0's" refers to data, and that square waves are periodic and symmetrical, then the parties you quoted, who were disagreeing with each other, were both wrong. If we go by Steve's definitions, then those parties, who were disagreeing with each other, were both right! I would agree that a plausible case could be made on the basis of either set of definitions. However, IMO it would be a safe bet that the presumably non-technical person who was arguing that what is being sent are 1's and 0's was referring to data, and not to logic levels. Best regards, -- Al |
digital signal not only has ones and zeroes, but rather characterised by sampling frequency and sampled amplitude as mentioned before voltage level. an arbitrary point of signal could be captured knowing the particular voltage and the value of the signal 0(low) or 1(high). The low could be let's say 0V and high could be +50mV etc... 0-s and 1-s are only rererence values of digital signal, but not the actual physical ones for those who thinks that 0s and 1s are 'traveling' accross the digital cable. electrones are the only ones capable of doin' that |
