Rrog, almost a parallel experience. I really started digital with a Cal Aria - it was wonderous compared to my previous CDP's and finally got me interested in digital. I then moved on to a Sigma and Proceed PTD, then an Alpha/Delta combo. I tried the Proceed in place of the Delta and found the combo a bit bright for my system and reinserted the Delta. I tried other CDP's with digital outputs and had a similar result, so when you said the Delta had a warmth you reflected my experience.
The PDT was an excellent transport but I was never fond of their DAC. I now use the Alpha/Delta in a headphone system using Senn 650's and a Woo W3. I replaced it with a BAT CDP, and then acquired a Raysonic 128, Wadia 302, and a Marantz 11SA3. They all bring something very different to the mix and it is nice to be able to choose to match music and mood. The BAT has been retired.
Excelit, I have no experience with any of those DAC's. EE/Mini Max gets good reviews and might work for you. Might! Ditto Scott. I don't know about 'analogue sound', but what you might find is that any of them may be more transparent than the Alpha if your system is sufficiently resolved to make a difference meaningful and you ears are sufficiently trained to hear these differences. Certainly you should be able to hear some tonal differences but which you might like may be more dependent on synergy with the rest of your system than anything else. May I suggest that it might be better to take a long range view and wait until you can afford to purchase a digital system, i.e. a CDP, or DAC/Transport combo, that will meet your needs. As
it is now your sound is wedded to your Rotel transport section of your CDP and the digital cable you use (although the latter should not be a big deal).