The bass is the real improvement in the superphon upgrade. I thought that the unit sounded quite good in stock form. It had great imaging, and a really nice midrange, but with the blackgates the midrange got even better and the bass was all there. I have compared this pre-amp to lots of other models, including an arc sp-8, and the new superphon (maybe slightly better) I love it. The power supply upgrades also help the bass, as well as the immediacy of the sound. I have three of these units, and they all run fine with the standard 16v blackgates. I have no idea why I still have three of them, but I think they are the biggest bargain of high fi.
