Audiolabyrinth,
I was not unhappy with the Krell KCT, thought it was a very good pre-amp. I purchased the EVO 707 when it was first released. I was one of the first to own this amazing processor. There were a lot of 'buggy' problems related to HDMI, all of which have been solved. The pre-amp section has always been stellar. It is better than the KCT in every way. Music emerges from a dead silent black back ground. It has deeper, tighter base. Better sound staging and better voice/instrument separation. The sound stage is more 3 dimensional. Everything sounds faster, more immediate, more vibrant. Music is clearer, more lifelike. I have been involved in high end audio and home theater since 1974. I have made many, many upgrades over the years. Replacing the Krell KCT with the EVO 707 was the single greatest upgrade I have ever made. The sound improvement was immediately, easily recognizable. I have Krell EVO 600E mono blocks for amps (R and L channels). I use Krell cast connections (except for my Esoteric K01 CD/SACD player). A great pre-amp can have an enormous impact on sound.