Just bought a MM Bongo 5 (S/H) and I've been noticing some type of unwanted overdrive sound in my setup. a Ampeg PF500 with the PortaFlex 210 cabinet. I've been using an FBass BN5 before and never noticed the problem. I'm not playing at a louder volume than before and the gain light isn't coming on. I know the Bongo has a pretty hot output, and i've been cutting off a bit of low end on the bass EQ, but still I'm hearing some of that sound. Just put fresh Duracell Procell batteries in the bass. Has anyone had a similar problem with a Bongo and/or Ampeg PortaFlex. Not really sure If it's the amp or the bass.