To answer the OP's question, no, it is not "absolutely" necessary to use any company's power cord with their power conditioner. However, good companies design their power-products with a technical goal in mind, intending them to be used as a system. I would suggest weighting your choice for a power cord toward the manufacturer of the power-distributor/conditioner while remaining open to other options.
It is surprising to still see so much argument over whether power cords make any difference in the first place, as well as whether they have any explainable technical or objective relevance. Not all people will hear a difference based on a host of variables and that's fine, but that is no reason to sling mud on others who do, or to state that _all power cords_ are a rip off and do nothing.
There is an overwhelming amount of anecdotal evidence from the world's foremost studios, mastering labs and electronics engineers --who evaluated and purchased after-market power cords for use in electronics design, film systems and for recording and mastering projects.
Dozens come to mind, including Sony, Bob Ludwig, Astoria, Skywalker and many others who carefully test _everything_ before buying. People convinced of conspiracy can always try to explain these away with more innuendo. They do exist however, and these professional sound engineers firmly believe in their value.
There is also easy to understand measurement data that shows dramatic differences between the average stock power cord and almost any well made (crimped and soldered 12 gauge or better) DIY or after-market power cord.
Yes, we measured this with an in-house designed peak-current analyzer but there is a common electricians measurement tool that provides almost identical measurement, absent some of the fine detail and scope. There will be an article on this fairly common device and its results published soon.
Whether these measurable differences can be directly linked to any one individual's experience in their own system with this or that make and model of power cord can be endlessly debated--which seems to be occurring here.
So, lets stick to a few facts:
A/V electronic power supplies pull current off the peak and trough of the AC sine-wave. Their rectifiers are switching on and off 120X per second. They are pulling current hard,--dynamically.
Compared to a simple motor or fan that pull current in an even flow, A/V power supplies are pulling impulse current in short, sharp bursts off the line. Any amp playing dynamic program material is a good example of this but all AV electronics are similar in the way current is received and processed.
For this reason, AV electronics are sensitive to in-line resistance to peak current. Meaning, the less impulse current that is put in front of the rectifiers when they open for each micro-second, the longer it takes to fill storage supply capacitors. For amps or passive power distributors that feed multiple components, we believe this is a very relevant measurement.
The vast majority of stock power cords have extremely high measurable resistance to peak-current. They are at best 14 gauge, but that's not their biggest liability regarding the efficiency of impulse-current and voltage delivery.
Common stock power cords are not using minimally crimped metal-metal connections, much less soldered ones. Their thin conductors simply rest against slits cut into the back of the three pins and then the mold itself holds the tiny connection points in place. That may be fine for a toaster-oven or your table lamp, but its objectively, measurably inferior when used with any good AV component power supply.
The _fact is_ that a 14 or 16 gauge stock power cord will drop close to, or more than 50% of available peak voltage and peak current that is measured at the wall outlet. No matter what the impulse current measurement is at your outlet, the majority of stock cords drop HALF of that. Now, whether one person or another can perceive a difference in sound or visual based on that objective difference can be debated, the measurement cannot.
Another fact is that you do not need a fancy (expensive) power cord to dramatically improve this measurement. Most crimped and soldered connection power cords of 12 gauge or better will improve peak current measurement significantly and yes, we believe that is related to sound and visual quality in a base-line manner.
There are many other considerations related to subjective performance of power cords in any single application, including component generated power supply noise and the radiated high-frequecy fields that are ever-present around electronics systems. Any decent quality, shielded or braided DIY design could address these issues, but there are also some good commercial designs from companies that know what they are doing.
Contrary to some peoples conclusions about commercial power-cord manufacturers, most are reputable, knowledgable people. There is the good and bad within all commercial categories of electronics manufacturers, speaker manufacturers and wire (maybe more because they are easier to make in theory and there are a of a lack of established "standards") but certainly there are also many that have legitimate designs and solid science behind them. To say that ALL commercial design power cords are snake oil or their makers are corrupt or ignorant is simply an unsupportable statement.
Anyone that claims all power cords are based on junk science or made by crooks are entitled to their opinion. However, they are also ignoring or discounting a massive amount of professional opinion, explainable science and anecdotal evidence to the contrary.
Regards,
Grant
Shunyata Research