Regarding handyman's comments, it's kind of an unfair comparison, as the Calypso is a 2-channel stereo TUBE preamp. You are not going to get the "organic" sound out of the Theta Casablanca. Also, the Theta is not a true analog preamp. All of the analog inputs are automatically converted to digital (A/D convertor) and then re-processed and reclocked for digital output.
That being said, I also had the same experience that handyman had. I actually bought an upgraded Casablanca IV with Xtreme DACs and the Dirac room control. I could not get the thing to sound good. Like handyman indicated, it had a very clinical and sterile sound to it and it wasn't really "full" sounding. As far as Dirac, I also could never get it to sound good. Some people love Dirac room control, but I am from the side that does not like room control. Dirac did weird things to the phasing and caused the sound to be "in your head" like headphones instead of way out in front of you. I could tame this by cutting back on the Dirac processing percentage and doing a multi-point microphone measurement, but it never sounded as good as with Dirac turned off. Dirac also over-compensated some of the bass frequencies causing the subwoofer to peak at frequencies that were room nulls. I discovered later that the only way to deal with bass problems is with tuned membrane bass traps.
I had an older Krell HTS 7.1 at the time and when I gave up on the Theta and went back to the Krell, it was like "god damn, this Krell sounds so good!!". The Theta just did not "sing" like the Krell. The HTS 7.1, and the S1200 that I own now, have the Krell fully discrete Class A analog circuits that are just magic, in my opinion.
The Krell Foundation is very good, but I don't know what it uses for analog circuits. Based on the price and all the Krell descriptions, I will have to assume that it uses op amps at this point.
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Regarding the MiniDSP DDRC-88A Dirac Live processor that is a HDMI correction device. The miniDSP will have to decode any Dolby Digital / DTS type data stream and then apply Dirac corrections to that. It will then have to re-encode those audio channels back to Dolby Digital or just send 5.1 PCM on the output. Either case, this is not optimum because it messes with the clocking of the audio data. If you really need room correction, it is a solution. But it is ultimately better to look at room acoustic treatments (panels / bass traps).