I have not installed Bybees internally on any of my gear, but I use the external Bybee filters just about everywhere. I have a pair on my tonearm cable right before it goes into the phono preamp, apair on the phono preamp IC's right before the Tact pre, a pair on the IC's from pre to power amps, and a pair on the IC's that go to the subwooofer. I also use Bybee filters on several power cords. The only place I tried to use Bybees and they did not work was on the digital IC from CDP to Tact's DAC. Everywhere else, they work wonders...and the effect appears to by additive and synergistic.