I was just about to buy a used JBL PSW D110 Subwoofer on Facebook Marketplace. I thought I'd check reviews first. Found this troubling thread. It seems that the critical problem was a failure of the output filter cap C6. The recommended replacement was a 10uF [U]100v[/U] NP electrolytic instead of the original 10uF [U]50V[/U] part, plus two other unrelated small parts. Some thoughts, from an engineer with decades of experience designing and fixing stuff: These amps are from about 1998, so age related failures are to be expected, especially in electrolytics. We must use electrolytics because they...