needed a longer AC cord for my 5D3 and tried E3462-C cord. this cord noticeably reduces noise even while it has more amps and computers share the same AC and audio source.
then I replaced all the AC cord with this for my tweed amps. the most dramatic change comes to ’59 5F1 which was quiet alone but it cannot be hooked up with AB box. even 60hz hum was loud when it shared the same AC power source without AB box. ground lift didn’t work either. it just shifted the noise frequency
this seller has the cable. but, only one of three was correct. two of them were E3462 without C. they are metal shielded and the noise was louder than 2 prong cord.
found another seller had the correct cable. and finally all of my tweed amps are dead quiet at any circumstance with E3462-C. even there is no difference between the original and modern 5F1 with or without the center tab.
and this typical ac cord wasn’t that bad for 5D3 but there is a huge difference with 5F1. E3462-C is still way better for 5D3 as well.