My latest Chem. CL90 in place and a 6H choke... This is one of the most quite amps Ive ever owned... nearly no DC ripple. the 6H only dropped the voltage after the rectifier by 1volt so it was a no brannier. The 1.5H still had some but not much, the 6H took it to the next level. I tried a 15H I had and that dropped the voltage too much.