It may have been the first ver of the X7 now that I think about it. I only had the AOU and the B7KU of the Ultra line. The X7 just didn't get me anywhere I wanted to be tonally. I did like it, great pedal. But that was when my ear was on the way out so I was somewhat turned off by it when I got it. But yes, I tried the AOU on it's own with an isolated power sup and it was still very noisy. I think I even had them send me another one and it was the same. Not trying to hate on DG. It just was what it was at the time. They tried to make it right for sure. Their cust ser was always top notch and above most.