Just looking for some help to figure out how to get better sound and tone from my setup. I have a stock Epiphone G-400 that I play through a Marshall Mg 15w amp. The tones I hear sound very deadened--like the strings had been choked. There is little sustain, though it does improve as I move from the clean channel more into the over-driven channels. I had thought maybe a new bridge upgrade might help (I was looking at the Seymour Duncan SH-5). But I also wondered if the amp might be part of the problem as I have read elsewhere that this particular Marshall model is not very good. I have been looking at the Line 6 Spider iii / iv 75w mostly for the sound presets.

I am a bedroom player using earphones most of the time with a very small budget for gear. I want to make sure that my purchase will make a difference to what I am hearing now.