Originally Posted by Vcell
I never played live with my acoustic.
Rule #1 in everything, BE PREPARED.
Don't go to the gig assuming it'll work, IME it never will unless certain precautions have been taken.
Sounds trivial, but whenever there's low natural SPL amplified acoustic instruments involved, feedback problems will arise.
If You can eliminate some or most of those problems beforehand, the gig will go much smoother.
Even though I've never found much use for it in the PA settings it's most commonly used by one school of thought, "ringing out" the amp/system is something You have to do if You have amplification of any kind
Knowing exactly what affects what is essential to trouble free performance.
It's always a compromise though, the best tone with least amount of feedback prone-ness.
Usually it's the tone that gets the soiled end of the stick.
If it's a flat-top ABG, a sound-hole cover is necessary to good, less compromise EQ'd tone if the SPL is loud.
If it's a carved top, a towel with a DB (a hankerchief will do with an ABG
) wedged between the tailpiece and the top works wonders.
If the sound crew is competent and used to be dealing with acoustic instruments, for other than personal monitoring purposes I'd forget using the amp.
Going direct will eliminate most of the problems with feedback.
If You accidentally make your amp feed back, the PA will most likely start to feed back as well.
After that, Your mic channel fader will be really low, or the channel is compressed to flatline before being heard.