For my listening tests, I removed my Naim Audio NAP 250 power amplifier from my system and substituted the Ultima 6, connecting it to my Naim NAC 82 preamplifier and HiCap power supply, reasoning that this would enable me to assess the performance of the Ultima 6 in the context of my own system. In later listening sessions, I substituted the Ultima Pre 3 for my Naim preamp.