My Dahlquist PDQ1500 was making a slight humming sound the other day (when turned off). I unplugged it before leaving for work and forgot about it for a couple days. When I plugged it back in, it started making lots of noise, with no signal applied. I unplugged it and managed to plug it in without the noise starting (if I wait a few seconds, it will stop). Anyway, when I turn on my receiver and apply a signal it might sound OK, but when it hits a loud passage it makes a popping sound. I'll probably take it apart this weekend and probe around, but the best way to fix it would be to replace the amplifier. I'll have to take measurements to see what size I need. I've heard about BASH amplifiers, sold thru Parts Express. Anyone got any experience or recommendations? I'd like to get it operating again and a better amp would likely improve the sound.