The iFi Uno is a tiny, affordable desktop DAC/amp that I found genuinely easy to live with: plug-and-play, smooth volume control, and a very practical PowerMatch gain switch. In my testing it sounded musical and warm, stayed clean with sensitive IEMs, and drove a lot of full-size headphones well (especially up to the mid-impedance range).
Pros
+PCM up to 384 kHz/32-bit, DSD256 and MQA support
+PowerMatch (two gain modes) works well for IEMs vs full-size headphones
+Analog EQ presets (Off/Music/Movies/Gaming)
+Smooth volume knob with on/off function
+S-Balanced 3.5 mm output helps reduce channel crosstalk
+RCA line out volume is controlled by the knob
Cons
-RCA line out is always on and does not mute when headphones are plugged in
-I would prefer a fully metal volume knob
-Limited headroom with some 250–300 ohm headphones depending on volume and recordings