I have owned the MX132-MX134 and now the MX 135 and I can say the 135 definetly exceeds the performance of the 134 in both analog 2 channel and digital 5.1 channel. The movie soundtracks that I have such a U571-River Wild-Saving Private Ryan etc have a much better central focus and I noticed more information pouring from my speakers.
The TI Chip Mc uses in the 135 is much much better than the Motorola chip used in the 134. As far as the 2 channel goes the 135 is as close to having a seperate 2 channel pre amp that I can imagine. As far as the Krell I really haven't listend since it doesn't offer some of the flexability the Mc's do. Like bass control, tone control, preset tone/surround set ups, sub in-out with 2 channel etc
The TI Chip Mc uses in the 135 is much much better than the Motorola chip used in the 134. As far as the 2 channel goes the 135 is as close to having a seperate 2 channel pre amp that I can imagine. As far as the Krell I really haven't listend since it doesn't offer some of the flexability the Mc's do. Like bass control, tone control, preset tone/surround set ups, sub in-out with 2 channel etc