Violectric HPA V550 Pro

While neutral-warm is a good description, I would say it's most noticeable characteristic is it's smoothness. Unfortunately the smoothness hides some of the details, and that is why it is not a stand-alone end game amp and needs to be paired with anther amp. I paired it very well with a WA-6SE that not only fits perfectly and matches V550 in dimensions, design and style, but used as pre-amp for the tube amp produces a very lovely middle ground, giving me a nice selection to pair with a variety of headphones, and this is where V550 can find's it's place in a end-game setup.
My most demanding headphones are an older Arya, that are very hard to drive, and with volume at 10-11:30 and 0db gain, it drives them perfectly, with a very coherent sound stage.
Unfortunately the motorized volume control still has some issues. At times it will refuse to move and you will need to go and manually move the volume knob to make it respond to the remote control. The problem is not bad enough to send it back, but annoying enough to mention it. I want to clarify that the issue should not be a decisive factor in picking this amp or not, it is more an annoyance when happens then a problem.
Conclusion: the amp has a nice sound signature aimed to be pleasing and enjoyable, not to reveal the more finer details in your track, and you don't have to worry about driving every headphone in your collection. My final overall score would be 9/10

Neutral-warm signature. Very good macro-dynamic and details retrieval all over the FR. It sounds grandiose, holographic, spacious, transparent and very well resolving. It has a lot of bass, with good extension in lower bass (rumbling) and slam/kicking in mid-bass, mids are very well represented and textured and highs don't go harsh or sibilant (even with bright headphones like Beyerdynamic DT 880 600 ohm, DT 990 600 ohm and DT 1990 250 ohm) and very well detailed. Plenty of power, using balanced connection I need to keep it to -18 dB for Focal Stellia (the most sensitive headphones I own), -12 dB for HE100SE, +6 dB for Susvara (the hardest to drive) and -6 dB or +6 dB for all other headphones in my collection (including 250, 300 and 600 ohm cans balanced or not). I paired it with iFi Pro iDSD Signature or FiiO K9 Pro ESS as DACs. Good job Lake People!