@rsf507, I never considered the Bricasti M12 Dual Mono Source Controller since I ONLY needed a DAC. I am using the SimAudio 700i V2 integrated amplifier and use its volume control. Based on my experience, I prefer to use the volume control in the pre-amplifier section and NOT the DAC. It is my opinion that the volume control function needs to be in the pre-amplifier section (and not the DAC).
HOWEVER, there are some people that PREFER using the volume control in the DAC, like the Bricasti M1, M12 and the Bricasti M21 DAC, and go direct to a power amplifier. Please note that Bricasti recommends using the volume control in the DAC and going direct to a power amplifier. Everyone has a different opinion on this topic. Most likely, if the DAC's volume control works in the analog stage (like the Bricasti M21 DAC) and is "perfectly matched" to the power amplifier, the system will probably sound excellent. On the other hand, I have excellent sound quality results using a pre-amplifier for the volume control so I am happy.
The only way to determine what sounds best for you is to demo using the DAC's volume control going direct to a power amplifier and also using a pre-amplifier volume control. Once you hear both connections, you can make a decision based on the resulting sound quality. Unfortunately, it is not easy to demo these 2 combinations so maybe you need to get additional comments from Audiogon members. I hope this helps.
BTW, the Bricasti M21 DAC is excellent and I am very happy with it. The M21 DAC includes both a sigma delta DAC and a ladder DAC so you have 2 options to choose from.