My WA22 just came in an hour ago. So far, it's perfection. No DSD playback noise issue with my TEAC UD 501 like I experienced with the taboo MKIII. No hiss, no hum from either XLR or 1/4 TRS. This thing is a tank. Very impressed at this point. Stock tubes are in for now. After everything is checked out, I will swap in the upgraded tubes.