Compare Bob Carver Black Magic 25 and Rogue Stereo 100?

Can anyone help me decide which tube may sound better, a -  Bob Carver Black Magic 25 or Rogue Stereo 100?  I will match either/or to :Martin Logan 20i.  Carver is new but only 20wpc. Rogue is used but 100wpc.  Both are online so no way to audition.  Thank you all for suggestions.