I just had the graphite nut on my Thumb Bass replaced with a brass adjust-a-nut that was supplied by Dana B. Goods. Also, I had an additional flush mounted strap lock installed to help with the neck dive that is common on this bass. The work was done by Carlos at Ron's Guitars in Groton, CT. He did a great job. The new nut seems to let the open strings resonate a little more and slap a little crisper. The new strap lock made a small improvement in how the bass hangs on my body. Oh, by the way, the brass looks much nicer than the graphite. I would recommend that anybody wanting to replace their nut go ahead and do it, but, it must be done by a pro. Never work on your wood by yourself !!!!!