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With the majority of consumer and professional audio equipment, and "regular" construction of commercial rca cables - would you say this is still a concern?
Yes. For unbalanced equipment, there is a total lack of control over where the currents are going. That makes equipment sensitive to AC and hums, buzz, clicks..equipment transients such as HVAC units, nearby lightning discharges due to high rate di/dt. For pro balanced equipment, they are addressing the pin 1 problem, but to date, only consider the issue to be that of an IR drop. Everybody I've read has ignored the rate of change of the current in the ground loop. And, they also ignore the source component output section as being sensitive to ground loop current.
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and none of matters as long as you have a well built cable, whether it be Monoprice, Blue Jeans, or $5,000 Audioquest. I've been in multiple DBTs over the years, all of them came to the same conclusion: cables only matter if they're defective. I wish they did alter sound, it would make things more interesting, but they don't.
Incorrect. See above.
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IC = Integrated Circuit, not InterConnect.
I used IC to mean Interconect Cable. A common nomenclature is important.
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In audio you only have to approach this characterisic impedance at the source end to be effective. All you are trying to do is minimize the effect of cable capacitance which you do by lowering the output impedance to close to the characteristic impedance of the cable. In audio you are not concerned with reflections as you are with RF. The wave lenths are too long, much longer than any audio frequency wire, even at the 40% reduced speed of the electrons in wire. Trying to do this at both ends (source & receiver) means you will loose 1/2 your voltage drive which is ok if you have enough gain to start with but you still have to take into account the fact that some recording are recorded way soft to begin with. The effects of capacitance may seem very subtle of the surface until you experience what reducing it to the absolute minimum on equipment that has a high source impedance. This not so critical on equipment that approches the impedance characteristic of the cable at it's source like Asus soundcards do ( they get very close, an order of manatude closer than most audio componants. Not quite a perfect match but close enough to no longer be an issue. I can now concentrate on other things like my power supply mods that I have aleady done)
Coupling is not a problem for me as I D.C. coup[e everything in my system I.E. I have no coupling caps anywhere in my system except for my tweeter amp crossover which cannot be eliminated for obvious reasons. Even that amp though is capable of amplifying D.C. if it were allowed to reach it. I found this arrangement to be the most transperant that when used along with my powersupply mods does a credible job of recreating the sound that I hear from live instruments, even from my small speakers in my room. I've don same type mods to my subwoofer & now have usable response to 16Hz, Flat to 20Hz.
I would imagine that most people don't have the resolution capabilities in thier system that mine does. My system has very high resolution & I can hear differences in wiring with this system when used with normal audio componants which have high output impedance (600ohms or higher).
Not entirely correct. In audio, the biggest issue is the load impedance and the mismatch to the line.
When the load (Z) is equal to the line, all events at the output are over after one transit at the propagation velocity of the cable. Nanoseconds.
When the load z is several orders of magnitude different than the line, then several hundred reflections are required until the load settles down to the current and voltage that the load needs to satisfy the source. For example, a 4 ohm load with a 150 ohm zip cable..If the amp steps 40 volts, 10 nanoseconds or so later, the load will be hit with 40 volts, but the cable can only supply 40/150 amperes maximum at this hit. After hundreds of reflections, the load current will indeed rise to the 10 amperes expected, unfortunately that timeframe is getting into the regime of demonstrated human localization sensitivity.
For IC's, it is another ballgame entirely, given that there is really no control over the current path of the ground. You have no idea (well, you might) how difficult modelling two IC's between components is, given that roughly half the signal return is via the coax driven, the other half is via the other cable braid, and the ratio is slew rate dependent.
jnjn
