Ivan TT
500+ Head-Fier
Hi!still searching the threat,
I have only low Impedance earphone,
how is the result (compare to ak4490 ) after ak4497eq mod to low impedance ?
I know you never done this, but ....I still searching the threat ...
There is no easy way to mod 4497 to have Lo Z output, due to the discrete buffer output stage, which is designed rather differently in 4495 version (which had 22Ohm output in latest revisions, by the way).
I removed output buffer and replaced it with OPA1622 on dip8 socket, but it’s a bit of hassle and looks like a car crash. Sound great though!
Having said that you can reduce output impedance by soldering 2x22 Ohm (or less) smd resistors on top of stock ones, they are 22Ohm.
But 22Ohm output impedance seems only to be an issue with BA-only earphones, DD and Hybrids do not seem to have significant issues with it.
Hope it helps.