I've been rolling output caps in my Extended Foreplay III (which feeds a Kaiju) and I confess I fell under the sway of what Doc B calls "cap of the month" syndrome. A question has emerged. I have a preamp out signal from the FPIII that goes to subwoofer amps that are set to turn on when there's a signal present. I've noticed that some highly regarded boutique caps produce a distractingly loud turn-on thump (which I hear through the subs) when I turn on the FPIII. Other caps are silent when I turn on the FPIII.
Since the only difference involved is the brand of 2.2uF output caps, does the presence of a turn-on thump suggest that those caps are passing DC? Are they flawed (or defective) caps? Or is a turn-on thump not necessarily a reflection of rogue DC from a bad cap? (It might be worth adding that the caps that thump don't sound very good.)
