Hi, I am the happy owner of a new Monarchy NM24. This is my 8th home (as opposed to portable) DAC, and the units previously owned are:
1. Silverstone EB-01
2. Lite DAC-AH (stock)
3. Lite DAC-AH w/ passive mods
4. Musical Fidelity X-DAC w/ a Little Pinkie PSU
5. Musical Fidelity X-DAC V3 w/ a Little Pinkie PSU
6. Oritek V4.1
7. HeadRoom 06 Micro Dac
The Monarchy NM24 has about 38 hours of burn in and the new 08 model incorporates both a Tube and an SS DAC as well as a tube line stage. For the utmost performance of the SS DAC Mr. Poong recommends a coupling transformer which he sells for $200 and I am actually thinking of getting it. The coupling transformer is not needed for the tube dac.
As you can see from the list of home dac's I listed the two most expensive ones I have owned are the MF X-DAC V3 and the Oritek V4.1. Both were very nice sounding units and the Oritek is a very good deal for its selling price of a tad over $600 (by the time you include the PayPal and S&H fees).
However I can say w/o a doubt that my amps have never sounded as good as they do now! And that is w/ only 38 or so hours of burn in on the Monarchy NM24.
Yes, it has more detail, clarity, extension, impact, etc. Things I would have expected as you climb the price ladder. What sets this dac apart is:
1. Air between the notes, you can truly tell where a note starts/ends.
2. Instrument placement, after closing your eyes you can visualize the location of the various instruments in front and around yourself.
3. Depth as well as width of the soundstage. This brings a sense of being there that my previous dac's were not able to do.
I would hope that by the time the unit reaches the 200 hour mark the nuances and further ability to separate as well as bring more musicality will become more noticeable. Now that I have had an opportunity to listen to the unit I do not find the NM24 reviews exagerate or bias.
The Monarchy NM24 is a single ended DAC, I can not comment on the Stello. BTW, you should check Audiogon, Mr. Poon is running an special on the Monarch NM24 (about a $500 savings).