Ittaku Posted January 2 Share Posted January 2 17 minutes ago, Keith_W said: You don't need a perfect square wave clock for audio purposes. This can go back and forth forever arguing whether you need a perfect square wave or not like a school playground saying "yes it is!" ... "no it isn't!!!". Also truly perfect square waves don't exist in the real world. They're impossible due to requiring an infinite number of stacked waveforms. 2 Link to comment Share on other sites More sharing options...
georgehifi Posted January 2 Share Posted January 2 (edited) 26 minutes ago, Keith_W said: You don't need a perfect square wave clock for audio purposes. Just so happens these are two of the best sounding CD transports I've had through my system over the years, over 15 of them, and both just happened to have the best clock square waves also. (go figure) Cheers George Meridian 500 MkII And this one the very rare Rotel RRD-980 (excuse the ghosting, scope wouldn't sync properly) And the worst sounding one was the very expensive CEC TL-2X MKII and here's it's bad square wave. (excuse the ghosting also) Edited January 2 by georgehifi 2 Link to comment Share on other sites More sharing options...
davewantsmoore Posted January 2 Share Posted January 2 2 hours ago, Keith_W said: You don't need a perfect square wave clock for audio purposes. I did not say you need a "perfect" square wave. They don't exist. I said, given a sine wave type clock, and a square wave type clock... you cannot use the sine directly. 2 hours ago, Keith_W said: This can go back and forth forever arguing whether you need a perfect square wave or not like a school playground saying "yes it is!" ... "no it isn't!!!". Quote No you don't. You only need the amplitude to cross the threshold for it to be interpreted as a 1 or 0. Whether the top of the wave is square or round is irrelevant. A sine wave type clock (the slowest possible change in signal between high and low of the clock wave) will not work.... the transition needs to be faster. This is why you will not provide me an example of a sine wave used directly as an audio clock (because you can not). So, I don't think we will go on forever. Link to comment Share on other sites More sharing options...
davewantsmoore Posted January 2 Share Posted January 2 2 hours ago, Ittaku said: Also truly perfect square waves don't exist in the real world. Indeed. I figured everyone was beyond that step. Link to comment Share on other sites More sharing options...
Addicted to music Posted January 2 Share Posted January 2 12 hours ago, davewantsmoore said: You both have this somewhat wrong. Sine and SAW clock inputs are then converted to a square wave.... you do not just "input a sine", as the "detection" of the threshold is not 9 hours ago, davewantsmoore said: You need a square wave clock for audio purposes You need a square wave for a clock for ANY digital circuit to work. clock type for input is irrelevant, you know that for a fact. 13 hours ago, davewantsmoore said: You both have this somewhat wrong. Sine and SAW clock inputs are then converted to a square wave.... you do not just "input a sine", as the "detection" of the threshold is not precise enough (it is a galaxy far far away from that). You can see this in the design of the interface between the input clock (sine, saw, whatever) and the audio clock, which are effectively high gain RF amplifiers. It is (can be) better to do it this way, because the source clock can be higher performance (jitter, especially low frequency), and the impedance match between the source clock, and where the audio clock goes can be much much better designed...... so it is very misguided to say "stay away from any clock modifications". If really what you mean is that you "need to be very good at what you're doing to even measure the performance let alone harm it" ... then sure, that is true. Have you seen benefits "measured" to indicate "sine or saw" differences? , and im not talking sales talk, im talking real measurements to show which will benefits better? Especially showing to outperformed the stock standard of the OPPO 105 device? if so please show the results here so all can see. 13 hours ago, davewantsmoore said: Doing these sort of things need very serious measurement, and RF isolation, pretty crazy power supplies, ovens, silly power supplies, and even designing out the piezoelectric effect. All this for "audio". really! We have $100-400 DACs that measures -120db and lower on jitter levels with just a standard 5V walmart supply. its not a circuit for military grade GPS tracking where precision is critical Link to comment Share on other sites More sharing options...
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