I received my amp8mk2s today. It really sounds noticeably better than amp1 or amp5mod. I haven't listened to the DX260 yet, but the DX240 with this amp is more than enough for me
I want to tell about my observations. I have been using this DAP for almost 2 months. It sounds really good, but... The main problem with dx240 sound is gain issues. It's like connecting a low-power amplifier to a powerful speaker system. I think the amp modules are lacking voltage. I will say right away that I do not use headphones that require a powerful amplifier. With the AMP8mk2s module, this lack of sound is felt much less and the sound of the DAP approaches a higher price level