1 Vince R Jr 5 months ago Holy cats!! What a difference.Got a 1992 6121 "Roundup" with the roller bridge a week or so ago and sounded good but.... Got the Tru-Arc this week and couldn't wait so just loosened the strings and swapped in the Tru-Arc. What a difference. It was like a blanket was lifted off the sound. The Tru-Arc came with a new bridge base curved for an archtop, I'd guess, so it was sitting on it's tiptoes and not making full contact with the top. Today I pulled it out and sanded the bridge base to the curve of the Roundup and....yowza!! It just chimes. I wouldn't have thought that given the Filtertrons (this being my first humbucker guitar) but it's dang twangy and chimey. Bottom line - happy customer.