@dill I've done it too. At one point I only had 1 power cable. The issue was it sounded much better on the DAC than it was on the amp. So there were occasions where I purposely left said upgraded cable on the amp with the intention of forgetting about it. I intended to forget about cables, but the bad sound was just irritating and the cable had to go back into the DAC. I now have 2 cables and there's no more battle.
While I understand why certain people can't hear differences between cables, and this can be a combination of a number of things. All of which can contribute significantly to the final result. As for me, cables have been a substantial upgrade for pennies.