Hey Daltonlanny. I've not listened to either amp but I do have some experience of owning a few of McCormack's better amps. Especially his custom DNA amps that are rebuilt with aftermarket parts.
Regardless, based on the write-ups on both of the amps you mention, I would guess that both of these amps are in the top 10 or even 5 percentile of all amps available.
At the very least, I would suppose that you could do far, far worse than either of these two amplifiers.
To get the best performance from either of these amps or other amps of this stature, you most definitely need a dedicated 20 amp circuit/line.
One difference would be that the JC-1's are monoblock pairs and the DNA-500 is one stereo amp. Therefore, the JC-1's would require two dedicated circuits/lines and two aftermartket power cables and/or line conditioners.
This may not amount to much but it still is an extra inconvenience and monies.
-IMO
