As others have mentioned, swapping the DAC isn't going to get you 'bigger, fuller sound'. Having said that, I'd consider the RME ADI-2 FS as a DAC because it has a 'loudness' feature that may provide the bass you're looking for at lower volume levels.
The SF speakers are probably the weak link in your chain. I had a single REL T7 and was pretty happy with its performance. If anything, I'd expect dual T9i's to fill in the low end pretty well.
Based on your desire to add 'fullness' and good imaging, what you probably want is a tube preamp. Tubes will add warmth (fullness) and increase the image size. However, images may be more vague with less pinpoint accuracy than an all solid state signal chain can provide.
In regards to imaging, perhaps consider speakers with ribbon tweeters. IMHO good ribbons image far better than any dome tweeters I've heard.
Also, is it simply a lack of bass that you're missing or does your current setup simply lack warmth? What setup were you running in the past that makes you think your current system lacks fullness? Could it be your current system is simply more honest than what you were previously used to an you actually prefer a system that shelves the high frequencies?
The SF speakers are probably the weak link in your chain. I had a single REL T7 and was pretty happy with its performance. If anything, I'd expect dual T9i's to fill in the low end pretty well.
Based on your desire to add 'fullness' and good imaging, what you probably want is a tube preamp. Tubes will add warmth (fullness) and increase the image size. However, images may be more vague with less pinpoint accuracy than an all solid state signal chain can provide.
In regards to imaging, perhaps consider speakers with ribbon tweeters. IMHO good ribbons image far better than any dome tweeters I've heard.
Also, is it simply a lack of bass that you're missing or does your current setup simply lack warmth? What setup were you running in the past that makes you think your current system lacks fullness? Could it be your current system is simply more honest than what you were previously used to an you actually prefer a system that shelves the high frequencies?