Installed Jargar Superior, medium A and D strings on my vintage cello bearing the label "Antonio Pansani, Romae, 1778. The A String was immediately better than the Perpetual A from the standpoint of volume and power. I also like the increased brilliance and clarity for this cello. My initial impression of the Superior D strings was that it lacked the brilliance of the A string. However, the string is opening up and is now proving to be a good balance with the A. string.