Jim,
I got one, is an easy DIY upgrade to do. If you want to get a complete DIY combo is a great idea. It certainly would improve the sound as you will get a cleaner electric input in to the crack. But do not expect a BIG change, you should try a tube swap, or just enjoy the speedball upgrade.
Where I really found a great improvement was combining the powercord and interconects kits to the Crack/Speeball/HD650.
Hope this helps you decide.
Miguel
« Last Edit: December 30, 2014, 12:57:11 PM by Mike V. »
Crack w/Speedball/HD650/DacMagic-100/
Mainline (on the way)/K702/ProJect Xpression III Classic w/ DL-103R/ Speedbox/Cambridge Audio 651p/