I bought one and it did make a difference in sound for my Tube Box DS. The bass was tighter and I perceived more detail from my rig. That said, it was perhaps a little too much detail. Sometimes I felt the music was a bit "etched" sounding. My speakers (Zu Audio Omen) can sometimes sound too detailed as well. Depends if you think you'd like some more detail in your system. In the end, I tend not to use the separate power supply and just stick to the wall wart.
Pro-ject Tube Box DS - power supply
I just bought a used Pro-ject Tube Box DS (not DS2) and will install it this week with some new tubes from National (Canada) that are recommended by an on-line tube retailer. I see a number of "audiophile" separate power supply boxes from China for sale that work with this model but do not know if I would perceive any sonic difference (or reduced hum perhaps) if I spent $130.00 for an external power supply. Anyone have any experience or insight that might help my decision?