If 0db doesn't overload your input, it's fine. The right way is probably to use a voltage meter, and set it to 2v. The easy way is to do it by ear
Since it's powered by usb, I'd probably set it fairly low, and let the GS1 do the work.
Home made chicken tortilla soup
Home made chicken stock (2 chicken carcasses, 1 medium onion, 2 stalks of celery, 1/4 cup of salt)
3 cups of crushed corn tortilla chips
2 cups of freshly ground chile powder (cumin, rosemary, ancho chile)