I think the issue of heated plug comes from Gauge no. of AQ-NRG1000 pc which is like 12 or 14 and it is best suited to be used with CD player or Preamps. Shunyata ZiTron Alpha (analog and HC!) is 10 Awg and is made for Power amps usage. There is Digital version of Shunyata ZiTron Alpha (higher gauges) for CD palyers or DACs.
Once I used two Shunyata ZiTron Sigma PC and wasn't impressed because of lack on extended HF, Mids were like kind of upper bass influenced and bass was not well defined as well. On their AC plugs, Shunyata uses Tellurium Copper as Base Metal and Nickel plated which is the worse case scenario in term of current conductivity and frequency integration. They use stranded wires instead of solid copper wire as conductors. Besides, they use a kind of inside "filtering circuit"! which could unbalance the sound based on what is the whole system configuration it is, like power conditioner, AC outlet, internal power supply of each preamp or amp.
I tried AQ-NRG-10 which was somehow better than Zitron Sigma. I guess NRG-1000 should be much better in term of resolution and extended frequency because it uses Solid copper wires and Silver plated over pure copper ac plugs. NRG-1000 would be a good candidate with tube gears. After trying dozen of different brands, I decided to make my own Power cords (all solid copper wires!) which I am very happy with. However, I am soooo tempted to try NRG-1000 on my Eisntein phono preamp or CD player.
Hope that would help,