uhhh that I'm not sure, maybe someone can offer a scientific reasoning for that. All I know is these are not truly balanced amps, so they are all converting SE in to BAL out. I mean if you have 6xx its not that hard to get a balanced cable for that.
Yes I do plan on getting a balanced cable for my 6XX at some point. I thought the 789 was truly balanced as it has balanced inputs on the back? Also if I were to get a balanced DAC to pair with it what would be a good recommendation? I have not seen the Massdrop SDAC balanced get dropped for a long time.