2 Guitar pre-amp D.I. box questions?

Question:I have this guitar

http://www.musiciansfriend.com/product/E...

It has (no equalizer or adjustments of any kind etc.) but does have pickups obviously and a stock plug preamp. Question is do I need a D.I. box (external preamp) to plug into a P.A. for best sound????? (Or is it really necessary? It already has a stock preamp) Also, I get horrible feedback when plugged into an elctric amplifier, why is this and how can I correct it? Thanks to both questions!

Best Answer - Chosen by Asker: I have this guitar

http://www.musiciansfriend.com/product/E...

It has (no equalizer or adjustments of any kind etc.) but does have pickups obviously and a stock plug preamp. Question is do I need a D.I. box (external preamp) to plug into a P.A. for best sound????? (Or is it really necessary? It already has a stock preamp) Also, I get horrible feedback when plugged into an elctric amplifier, why is this and how can I correct it? Thanks to both questions!

It's an electro-acoustic guitar so the sound board will pick up vibrations from the loudspeakers and the sound hole will let amplified sound into the guitar where it will then resonate beautifully inside that huge dreadnought body. All this is then picked up by your on board pick-up (piezo?) which sends it back to your amplifier where the whole cycle kicks off again. Result - feedback. I don't disagree with the previous answers except that I would suggest fitting a feedback killer to the sound hole of your guitar. This is a rubber pancake thing that just sits in the sound hole and helps to stop amplified sound entering the guitar and resonating around inside it. They are not expensive. As has already been suggested, do not stand in front of or too close to the speakers and keep the overall volume low enough. If you need volume, then you need to think about other solutions. My Marshall acoustic amplifier has a feedback limiting circuit that can be switched in though you lose a little sound quality. My guitars all have a notch-filter on the pre-amp so I can sometimes tune-out the feedback frequency - no good for full-on screeching feedback. One of my guitars has a phase-shift switch which changes the phase of the wave leaving the speakers so reducing the likelihood of feedback returning - as long as I remain where I am. Finally, some acoustic effects pedals (eg Zoom 504) enable you to select a level of feedback suppression with each effect. The inexpensive but pretty effective solution is the feedback killer in the sound hole. Good luck - I know how frustrating it can be.

you just need a good amp, valve, and mike it up, forget DI, it gives the sounds that you don,t want, TRUST ME, i,ve been there, terry..,feedback can be a lot of different things, it could be the mike,s are picking you up, it could be anything. mail me if you want to, terry

It's got a good pre-amp (an LR Baggs) so all that a preamp box would give you is EQ. (which you can do at the amp)
Feedback is caused by being too near the amp speaker or having the volume too high - just move back & turn it down!