Tube preamps oftentimes prefer and sound best with ribbon based cords. I suggest Walker ribbons or Electra Glide ribbons. These two cords sound different, and will emphasize different aspects of your tube preamp's sound. In either case, you will notice less grain and greater dimensionalty, with a greater sense of texture and immediacy. Negatives can include some tonal washout or some dynamic restriction depending on the gear being used.
MGDeWulf
MGDeWulf