I have been playing double bass for 51 years. Mostly jazz, but for the last 2 years have been playing with my church band, a blue grass gospel group. We have a couple of guitars, a mandolin, and the bass playing thru combo amps on stage, with the rest of the group going thru a couple of condenser mikes. Last month, we had a guest band play at the church, all acoustic, the bass player (one of my students) tied an SM57 under her tailpiece and played thru the church PA. This was the first time that I got to sit in the audience and hear the mix from that perspective. I was blown away at what a great sound they produced. I suggested to the church band that we ditch the amps. They agreed, and the difference is stunning. I had been using a full circle into an AI Contra. I replaced that with an AKG C419 condenser mike into the church PA. I can't hear myself in the monitors, but the congregation raves about the tone, and says that it is plenty loud. Now to my question. When playing thru my amp, my intonation (to my ears) would run just a little sharp or flat. Nobody else noticed it, but it was bugging the hell out of me. Since playing acoustic, my intonation seems to be spot on. I don't understand this. I have a theory that maybe my amp was generating overtones in my bass, causing my ear to be off? Anyone out there ever experience this phenomenon? Drurb, you're a psycoacoustician, you have any thoughts on this?