20m or 2m no difference. length of powerline is much longer could be 2km
The efficiency of current has nothing to do with length of power cord.
Longer ones are usually more convenient to reach to power outlet from the placement position. I've seen those super fat ones that you can hardly bend, but "sounding super good" LOL! If you can't even bend them steep enough to reach the outlet, what's the use?
The rule of thumb is super-simple, if you still unsure how aftermarket power cord works or how will one work in your set up, there's no need to bother and use stock one and save $$$. I still don't know why I should change my power cords unless they break and live with that with no regrets whatsoever.
Many high-end components might not have sufficient "defense" from EMI of powerlines and may require to use SHIELDED powercord in case if such problem NOTED. See? I'm not completely against aftermarket powercords after all, but highly prefer well-engineered components that aren't susceptible to EMI, RFI or other electrical nature disturbances.
A representative will always tell you to purchase because it will improve sound, but in fact not always true and most-likely not true.
The efficiency of current has nothing to do with length of power cord.
Longer ones are usually more convenient to reach to power outlet from the placement position. I've seen those super fat ones that you can hardly bend, but "sounding super good" LOL! If you can't even bend them steep enough to reach the outlet, what's the use?
The rule of thumb is super-simple, if you still unsure how aftermarket power cord works or how will one work in your set up, there's no need to bother and use stock one and save $$$. I still don't know why I should change my power cords unless they break and live with that with no regrets whatsoever.
Many high-end components might not have sufficient "defense" from EMI of powerlines and may require to use SHIELDED powercord in case if such problem NOTED. See? I'm not completely against aftermarket powercords after all, but highly prefer well-engineered components that aren't susceptible to EMI, RFI or other electrical nature disturbances.
A representative will always tell you to purchase because it will improve sound, but in fact not always true and most-likely not true.