We have to ask, where does the power supply of our equipment end? At the transformer primary? At the on-off switch, the fuse? The power supply sees the power cord as part of the power supply. The charging of first cap in the supply causes high current RFI spikes to pass thru the C of the power transformer and on to the AC line. I have heard many different aftermarket power cables, and they do affect the sound of the equipment. If you do not hear the difference in power cables that is great, you can save time and money not buying better power cables. 
As mentioned, look for the thread about 'AC Filter Box...' by me. It's a big thread, the graphs are near the end. Maybe searching via Google can help as the site's search functionality has been so-so in the past.
And by all means, always do your own measurements.
Can you provide a link to the actual thread, I have tried to find it but not sure I can see it - I looked at threads you started and it was not obvious to me (probably me just being dumb!)
It may be this almost 2000 post old thread:
https://audiophilestyle.com/forums/...boxes-linear-psu-and-balanced-power/#comments
https://audiophilestyle.com/forums/...boxes-linear-psu-and-balanced-power/#comments
It would be useful if everyone posting about their experiences with power conditioners and cords would provide some information about their location when the observations were made. It seems to me that observations made in a high-rise apartment in a city center might have more problematic power than a rural single-family house.
For example, my location is rural, single-family house, about 5 miles from nearest city center with a population of about 20,000. So, I do not expect to have a noisy power line. I would be interested to hear other thoughts on this theory.
For example, my location is rural, single-family house, about 5 miles from nearest city center with a population of about 20,000. So, I do not expect to have a noisy power line. I would be interested to hear other thoughts on this theory.
Markw4 and Speedskater, good observations. I do have all of those plus an electric dryer, and I also think the line perturbations would be intermittent. Which makes it difficult for the DIYer to find a way to capture those perturbations and evaluate their significance. The intermittent issue also makes listening evaluations much more difficult.
Our equipment due to the charging of the power supply capacitors generated harmonics of the power line frequency. If a inductor is inserted in the power line it reflects theses harmonics back into the equipment. Would it not be better to allow this unwanted energy to pass out to the main power line and get away from our equipment? A .1-.5uf line rated cap right at our equipment will short out some of the harmonics.
1. Why, then you are into the EMC emitting business, highly frowned-upon: and not helping the other equipment in your system.
-2. and yes , that is exactly why RFI filters - which are generally designed to prevent emission (& help to meet standards in this regard) rather than just deal with some putative 'mains noise ingress' - are designed the way they are. And why looking closely at teh test curve vs source& load impedances is critical to a useful outcome.
Deal with the incoming, and possibly outgoing, problems on each box. For anything line-level - that can be quite trivial, but made bombproof in terms of psrr, quite simply.
-2. and yes , that is exactly why RFI filters - which are generally designed to prevent emission (& help to meet standards in this regard) rather than just deal with some putative 'mains noise ingress' - are designed the way they are. And why looking closely at teh test curve vs source& load impedances is critical to a useful outcome.
Deal with the incoming, and possibly outgoing, problems on each box. For anything line-level - that can be quite trivial, but made bombproof in terms of psrr, quite simply.
The effects of ferrites may be attributed maybe to couple of things. At least, two of those things come to mind at the moment. Ferrites can produce hysteresis distortion as described at: https://purifi-audio.com/2020/04/28/dist/#:~:text=Unlike most forms of distortion,a hysteretic mechanism at work. Also, even if their effect is that they mostly tend to remove unwanted RFI/EMI, the possibility remains that a more fundamental problem in the system will be exposed by reduction of the noise effects. Both types of ferrite results/effects/consequences could potentially occur in the same system.
Therefore, some measurements and or experiments may need to be performed to better optimize the system. Not everyone seems to be up for that though. However IME such steps may be necessary to take a design to the next, although not necessarily the final, level.
Would suggest to discuss strategies for specific cases rather than try to stay general for too long. Don't know if there is a generalized approach that will always work.
Therefore, some measurements and or experiments may need to be performed to better optimize the system. Not everyone seems to be up for that though. However IME such steps may be necessary to take a design to the next, although not necessarily the final, level.
Would suggest to discuss strategies for specific cases rather than try to stay general for too long. Don't know if there is a generalized approach that will always work.
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Exactly. The absence of rigorous ABX testing data (for example) is, as always, deafening...
If the 'I changed this/that and it sounded better/worse' works for people's hobby that's fine, but personal revelation should never be accepted as anything but opinion in scientific discussions.
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