amdan, you should absolutely try the Mogami Platinum Signature between your pre and power amp, as well as from the DAC analog out to preamp in (is this a balanced connection?). Just keep in mind these are sold as singles. And terminated with XLRs, so only usable as such. Unless you choose to re-terminate yourself.
From memory, I played audio through the Platinum Signatures for somewhere around 60 hours, at which point they were largely "settled in". You will hear the potential after the first hour, though.
Brian