I have heard the littledot mkIV, and it pretty much sounded like any other solid state amp as well so i though eh, littledot is just another shammy company... but then I discovered the MKIII - and i ordered on the next day!! TRUE tube sound, warm, euphonic - FULL....i can list adjectives all day, but until you hear it for yourself, nothing I say can do it justice. You can also go get ripped off, i mean go buy one of the woo audio amps for much more, and you will either get the same sound as an o2 (firefly) or a similar sound to the mk3 at over 2 thousand dollars. Insane how people spend thousands on GERMAN MADE Or USA MADE tube amps, when the best tube amp on the planet is made by a small chinese comapny  that writes it's manual in broken engrish. 
 
If you work hard for your money and want the best sound known to mankind that also happens to be at the best price: 
 
Odac -> ldmk3  -> sennheiser hd650.
 
You are welcome.