Bluebird U3 Mini

Hello fellow head-fi-ers!
This is actually my first review, so I'll try my best to give you guys some quick honest feedback on this product.
 

Overview/Design

1. brushed aluminum feels and looks nice, making for a good balance between value and looks
2. seems to be rather durable, have only dropped it once (from a decent distance), and not a scratch/dent was made
3. volume knob isn't very loose, and jacks feel sturdy and secure
4. size is very nice, roughly equivalent to an iPod Touch 4G (slightly thicker though)
5. if used while charging, there is a loud buzz
6. 3.5mm cable that came with the amp is gold plated and thick!
7. battery life seems to be pretty great! (have used it on and off the past 2 weeks, and still haven't had to charge it)
8. power output ROUGHLY: ~80-100mW @ 32 ohms (with my DT770's: ~32-40mW @ 80 ohms)

 
When I first received this amp from aliexpress, one of the first things I noticed after I took it out of the packaging was a slight rattle when shook. I decided to investigate, taking apart the amp, and the only thing I could make out that was rattling was either the battery or the wires connecting to the battery (see below pic). Really didn't do much adjusting at all, just a little nudge to the wires and the battery, and, after putting it back together, the rattle was gone!
 

 

 

 

 

Sound Quality

1. better than expected, was rather skeptical before purchasing
2. nice, smooth lows, doesn't seem to modify their sound very much at all
3. the lower mids are a little more pronounced, while the upper mids and highs seem to be negligibly affected
4. great for the price!

 
On aliexpress and elsewhere, the U3 Mini is advertised as having a warm sound, but from what I have experienced so far, it really seems to be more of a warm-ISH sound. Yes, it is not bright, but I would not say that it is very warm either.
 

Conclusion

Would recommend this product if you are looking for a portable amp in this price range! Design and sound are very nice, and for only ~$35, you can get a decent amp to power your cans!