Hi, electronics mavens! Help me get my head around the concept of bass instrument output impedance vs amplifier input impedence - which is where I think I'm having a problem. I rehearse through a Roland D-Bass 2x10 combo. Generally a nice little amp. It works nicely with passive electronics in my basses. Get damned loud using those basses, too. But when I bring in an active instrument, especially one with a really hot output, there's no combination of settings that allow any kind of sound volume to be pushed out of the amp that's like when it's being fed from a passive instrument. And note the passive basses are not quiet, either. One in particular has Bart P-bass classic bass pup's that are pretty loud. Clearly, when using the hot active basses, the input is overloading. I've switched it from "passive' to "active," which should adjust the input impedance, and also readjusted the input gain level. But even doing this, the volume drops so much I get about 2/3 the max volume out of the amp that i do when using quieter passive basses. It seems like the input gain starts to act like a compressor.limiter, and just maxes out and goes no further. But as I say, with the semi-hot passive basses, this is not the case. I suspect there's some kind of impedance mismatch going on, but not sure. I've not quite gotten my brain to absorb that. I've always viewed it as the input impedence needs to be substantially higher than the bass output impedence, rule of thumb being 10X higher. The input impedance on the amp is claimed to be 1 MOhm. So all comments and thoughts are welcome on this one. Thanks!