I have experienced similar numbers on my P10. Have had mine over a year and it is a brilliant piece of audio equipment. Remember the readings also depend to some degree on the power you are receiving from your outlets as well, (Electrical company). What type of outlets do you have? I picked up a pair of PS Audio Classics and are pleased with them. For the last few months my THD output has been a steady 0.1. When I first connected the P10 to audio components I was receiving THD output readings of 0.2 to 0.4. As I leaned out the system of components, and some interconnects, (integrated receiver) replaced with a dedicated Preamplifier with separate Power Supply for Preamp, passive/active and removed an extra CD player and used balanced connections I found the numbers on the P10 stabilized. Do not know if this has helped, but numbers did seem to change on P10 as I was tweaking. At present the music I am hearing through all sources is sounding Fabulous, be it Vinyl, CD or AIFF files.