The korsun / dussun v6i is a monster of a power amp costing around 800 usd. It really is a poor man's krell or Mark Levinson that is built like a tank with dual mono construction in a stunning but large aluminium chassis. It is kind of a class A build in that the first few watts are class A were then it slides into class AB mode as it is driven harder; with output powers of 2x300 W into 4Ω and 2x150 W into 8Ω.
Sonically the dussun V6i was rather hit and miss. In the right combination of source and speakers it could sound good but more often than not it sounded a lack luster. The main issue I found with this amp was the lack of dynamics and musicality. No matter how loud it was driven into certain speakers it sounded a flat and soul less. It was too source and particularly speaker dependant.
This amp can be split by links at the rear so it can be used as a pure power amp. I ran the amp in power-amp only mode using a DIY 12b4A tube pre-amp and this was a much better combination on Monitor Audio Studio 20SE speakers, the tube pre adding vastly better dynamics than the built in pre and a little warmth to the cold sound. This seemed to be the preferred way to use this amp but it kind of defeats the purpose of buying an integrated.
On a pair of Martin Logan electrostatic speakers the V6i in power amp mode was again not a good match I had hoped for when compared to driving the Monitor Audio Studio 20SE. The amp again sounded a little flat and un-dynamic most days. It hardly got warm to touch no matter the load or levels so it made me believe it was very under-biased, under driven and capable of much more. I think this could be a good amp in the right system and just a shame I did not have a service manual to modify it. I am sure Duusun could make some minor changes to the design to improve dynamics and maybe add a little warmth and soul to the sound. As it stands I would only recommend this amp if you can pick it up for a very low price and are a regular box swapper meaning you can find a good combination of speaker and source to match it and bring out its best. Now if the bias point could be changed by someone highly technical to study the pcb it could maybe shine.