I recently modded my other DSD trying to achieve exactly that (my first DSD has x2 paralleled OPA1622 per channel, I estimate its output Z is around 3Ohm). Stock DSD (assuming we are discussing AK4497 based one) in addition to output resistors has 22Ohm emitter resistors in the discrete transistor voltage follower circuit which is a little bit high (I usually see values of few Ohms (sometimes below 1Ohm actually). These are beneficial for preventing thermal-related effects, but 22ohms? Making output impedance 44Ohm effectively? Seriously? I replaced those with 5.6Ohm 0805 resistors and bypassed output caps and resistors altogether, I don't hear as disturbing change in FR as with high Z output, but still evaluating this mod (including with multiple BA/low impedance IEMs). I also used bypass capacitors on these resistors (although in slightly non-convention way), this may improve output impedance further. PS: currently listening to this mod using TF10, they are QUITE sensitive to high output Z becoming way to sizzly and lacking punch in LF, I am satisfied with how they sound right now: lows dig quite deep and there's good (but not overwhelming) sparkle in there too.