regarging components that have a 20a AC IEC

Your owner's manual will be your best source of information. When I owned a ML 333, it came with a captive 15amp cord to be used with a standard 15amp circuit. I later converted the cord to a 30amp and used a 30amp dedicated circuit and could not believe the sound improvement. Please keep in mind I was driving very inefficient and low impedance speakers at the time.

A local electrician could install a dedicated 20amp line for less than the price of an aftermarket hi-end pc.

Does the stock cord have a 15A, 125V plug(5-15P, two vertical prongs and ground) on it? If it does; the amp's cord is designed for a 15A wall socket and you will be fine with replaced the IEC connectors, on the amps. Is it safe to assume that you have a dedicated circuit, since you already know the value of an upgraded power cord?

I bought a few Furutech 15 amp IEC with really nice contact blades. And they had screw down terminal which accept 10 gauge wire. A big plus.
I swapped out the 20 amp IEC in my (used) Furman REF20i so i could use my Pangea 15amp IEC powercord in the Furman.
No problem at all.

Instead of incurring the trouble and possible risk involved in installing an inexpensive 15 amp connector in the amplifiers, why not just put an inexpensive 20 amp connector at the equipment end of your DIY power cords?

In saying that, I'm of course assuming that the wiring in your "very high end" DIY cords is sufficiently rated to be able to handle 20 amps.

Regards,
-- Al

Assuming these are nice mono amps, the idea of alterning them out of thriftiness in altering power cords seems crazy to me. You would not be able to sell these amps as being unaltered from manufacturer, and you'd take a big hit on them.

And just how would a cheaper 15A IEC guarantee that it would not alter the amps' performance in a bad way? So, with that potential reduction in sound quality you would be chasing to catch up again... Not a good plan, imo.

This is a perfect time for a PC shootout between several contenders! You have a sea change with the amp anyway; push the experiment further with a 20A cord-O-rama comparison! :)

Or, get a 15A/20A adapter for your power cords.

But what you REALLY need to do is use your stock 20A cords with some badass mongo power supply/filter device costing about $3K. That will fix everything. ;) Tee hee hee