I think I get your logic, but the fact that a DVD holds more data then a CD has nothing to do with the quality of the onboard DAC.
The discussion of resolution with a DVD is traditionally a discussion about the quality of the video. Keep in mind that the amount of audio information per channel is the same.
From your description it doesn't sound as though you are comparing apples and apples...
If you play the exact same material on two devices, it is pretty much a given that one will sound better then the other. This can be due to a very wide range of factors including internal components and circuitry, the comparative quality of the power supplies, the cabling, where they are each physically located in the room etc. If you are not comparing the same recording there are even more variables...
Finally it is not a given that Redbook upsampling sounds better. Many people here on the Gon do not like what upsampling does to music.
The discussion of resolution with a DVD is traditionally a discussion about the quality of the video. Keep in mind that the amount of audio information per channel is the same.
From your description it doesn't sound as though you are comparing apples and apples...
If you play the exact same material on two devices, it is pretty much a given that one will sound better then the other. This can be due to a very wide range of factors including internal components and circuitry, the comparative quality of the power supplies, the cabling, where they are each physically located in the room etc. If you are not comparing the same recording there are even more variables...
Finally it is not a given that Redbook upsampling sounds better. Many people here on the Gon do not like what upsampling does to music.