i need a di box to run my amp to the PA. >what are my choices if i have $40 and under to spend? (please reccomend brands, models, or whatever you can). experience with it would give me some reassurance. >what does "ground lift" mean? effects, etc. are not necessary at all. i just need it to run from my amp to the PA and get rid of some amp noise. di boxes that don't use batteries (or any outside power source) is preferred.