This might be a bit vague.....but I heard an artist with a warm effect to his voice.......my friend told me it came from the preamp.......is this true/possible?
Warm is an extremely vague term that can mean different things to different people. To some, warm means "distorted," while to others it means "rich harmonic overtones." To some, it may mean a "rolled-off high end," while to others it means "clear and intimate." There are preamps that can bring out all of those various qualities, but defining which qualities you want is the first step.