Did a battle of the bands last night (hey it was to get gigs, not to battle......although we ended up winning....whoooo) and had to play through an unknown rig. Soundman told me they had problems with first band's bass. I take a look at the amp and see why-guy before me did everything below wrong....
Hints:
1. Do not plug into the tuner jack. Plug into the one that says "input"
2. Check for a passive/active switch. If you have a passive bass and the amp is set to active, I don't care how much you turn up it'll sound like

. If you have an active bass and it's set passive, you'll clip like mad.

3. DO NOT boost all of the EQ sliders all the way. :scowl: Set em flat and go from there. Cut where possible rather than boost, and remember the more low you boost the less headroom you get to play with. I ended up barely boosting the 2nd and 3rd treble sliders and cutting the lowest bass one.
4. Unpush any "effects" buttons. Trust me, the "zing" button isn't gonna be pretty and you don't have time to re eq. Ditto for any "boost" button. That's what EQ's are for.
5. Turn volume knobs down, play a note, and turn up slowly from there. The speaker will greatly appreciate you not jacking the knob to 10 and whacking a note.
Ok, additional hints:
1. Check ground at outlet

2. Get drummer to look behind amp and find off/on switch so you're not feeling around blindly
3. Use your *own* cable-trust no ones. (soundguy agreed with me on that one!).
4. Smile and have fun

5. Better to be too quiet than too loud. Bands that are too loud tend to not get as many gigs (at least around here). They'll hear you......you are bass

.
6. Oh yea, start with your volume at about 3/4's on your bass. That way you can turn up on the fly if needed without fumbling on an unfamiliar amp.
7. Be thankful you aren't a guitar player. It's harder to use someone elses guitar amp than someone elses bass amp.....bass amps seem to be more consistent in sound (in my short experience......*hides from amp peeps*)
8. Have fun

9. Be nice to everyone-that chick you just knocked into might be the owners daughter....that guy you were rude to might just be the owner.
10. Be REALLY nice to the soundguy.....their job is hard enough at those things.
11. Get off the stage. Quickly. Roll cables up/sort items OFF stage.
12. Triple check for left items-count before you go up, count after.
13. Last of all....mark your stuff. Microphones all look the same! (we had to ID ours by location).