When making DIY power cable for an amp, do you:

In my experience cables without a shield can be more open. Clear Day Cables I believe have no shield on their IC’s and I’ve never had an issue with them picking up EM/RFI - they sound pretty darn good. I have several Kimber Kable PC’s that I believe have no shield as well and no problems in my system. If you’re going to build your own or buy a cable with the shield make or have them make it so you can float the shield to see how it works in your system. As mentioned above I believe, on a PC the shield if needed is connected at the wall receptacle only. With the proper cable geometry that cancels EM/RFI a shield is not required. Phono cables more than likely do need to be shielded. 

What are your thoughts on shielded power cable versus non-shielded?

I’ve got a response from one supplier/maker of higher end power cables about the use of shielded versus non-shielded and his response was:




Hello,

Thanks for your message. This cable is made with XXXXXX XXXXX XXXXX which is not a shielded cable. Our philosophy with shielded AC cable is that any benefits it may have, slightly lower magnetic leakage currents, are mitigated by the increased cable capacitance of the cable due to the shielding.

This equates a lack of dynamic range when comparing a shielded cable to its non-shielded counterpart, all things being equal.

During the testing phase of this design I concluded that even with unshielded unbalanced interconnects connected to the same device as this cable, I did not find any EM noise induced from this cable to the unshielded interconnects.

Thanks,


XXXXXXXXXXXX

I may not have been mentioned exactly like that, but me being ignorant of the process...that’s what I interpreted it as. 

Mr. Squares is correct. 

Where you heard the ground is only connected on one side might have been interconnects? 

I'm thinking, even old Fender amps that you would "upgrade" a two-prong to a 3-prong, it is expected you would attached the ground wire to the chassis. 

I just can't think of a situation where you would want to build a power cord and not connect the ground at both ends.

+1 erik

IF you are creating a 3 pin, grounded power cord THEN you MUST connect all three at both ends. The center pin on both ends is ground, but the small blade is "hot" and should be properly attached at both ends of the IEC plugs. This is because typically only the "hot" side is fused.

However! :)
If the power cable is shielded you have a fourth conductor. This thin shield wire connects to the ground(green) but only at the wall side.

If you are creating a 2 pin, ungrounded power cord, then of course, there is no center pin on either end. The only device I have like this is a sub, which is the only one with a 2 pin IEC socket.

Best,
E