I just feel that I need to weigh in on the subject once again.
Okay, so you found out that Yamaha is using the same DSP processor as what is in the McIntosh. Is it just the same DSP chip, or is it the same processor board by Momentum? I would think that it is not the Momentum board in the Yamaha and is likely a different board, or perhaps even Yamaha's own board design using the chip. If the later is the case, then you have to question the quality of Yamaha's design versus that of Momentum. You also have to consider how good of a design the Momentum is in the first place.
Even aside from all that, once you have a processor board, such as the Momentum or something else, you have to know how to use it. The quality of the circuitry and design that is outisde of the processor can make or break the quality of the signals. Such issues as noise isolation/rejection, proper grounding and the speed/slew rate of electronic components can readily effect how well the processor will perform. If the design isn't well thought out and capable of delivering signals up to the capability of the processor, then it doens't matter if it's the same processor used in a McIntosh, Denon, Marantz, Yamaha or whatever else. A system is only as good as it's lowest quality component/design. A processor is programmed to do what it needs to do, any limitations that aren't in the programming are due to either the limitations of the chip, or the limitations of the supporting circuitry. The only way to get the most out of a processor is to have the outside circuitry meet or beat the processors requirements.
With that having been said, I would not be totally surprised to find higher quality circuitry in the McIntosh than in the Yamaha. First off, there is more space to do stuff with circuitry-wise in the McIntosh than in the Yamaha. Also consider that Yamaha is a global company that has to meet deadlines and price points for consumers, therefore they have constraints on what they can do.
Now, I'm not saying Yamaha is a bad product, they make some great stuff. They just don't have the "freedom" that some of the higher end low volume brands do. On the other hand, I'm not saying that the McIntosh is necessarily better than the Yamaha or something else that uses the same DSP processor. It's all a matter of how well they did their homework.
All I'm saying here is that the DSP processor alone does not make for a fair comparison between receivers/preprocessors.
