I received the Nuforce DDA-100 last week, but just had a chance to set it up on Monday. It's a cute little unit, smaller than it looks in the pictures. Fit and finish is good, better than expected for a $549 unit. One minor complaint is the small speaker connectors. They are a little tight for large spade lugs but banana connectors work fine.
Sound after eight hours of playing white noise: very nice, surprisingly so for a unit of this price. This little amp is very musical and detailed. The amp played well and sounded very good with all the speakers I tried, although I didn't crank up any track to extreme loudness since this is an office setup. Jazz, vocals, and chamber music were great. Rock music was very good, considering that I haven't tested the unit yet with any full-range speakers. As expected, large orchestral pieces sounded very nice if not a little "balled up" in the middle, which again could be my choice of speakers.
I compared the little Nuforce to the Peachtree Decco (original) unit I have been using. In a nutshell, the Nuforce amp was much more open and detailed than the Decco.
Speakers I have tried with the DDA-100 amp include Dynaudio 52W, Snell J/II, Salk/Ellis 1801b sealed monitors and a pair of Tannoy Stirlings I just acquired. All sounded great, although I will almost certainly use the 1801b speakers with this amp. It made a very sweet, detailed and accurate (to my ears) combination.
Source was my mac mini music server playing through Audirvana, both connected directly via toslink or via WiFi through an Apple Airport Express connected to the amp via toslink. Both worked extremely well, and although the WiFi connection is limited to 16/44.1 resolution that is how I am going to use use this amp going forward.
All in all, I am very happy with the Nuforce DDA-100 amp. I was initially curious and concerned with the "lack" of a DAC, but its internal PCM to PWM conversion seems to work as advertised and deliver the goods.
