Very interesting information Silverprouts.
There's no denying the bug (which we thought was cured) is a serious issue, my exact thoughts when it first occurred many months ago on an earlier firmware. We really assumed for sometime it was patched in a firmware update, well, it appeared that way until more reports surfaced most recently (but not at the same percentages as originally)
And I agree, I was very vocal about it last year, it's like a ticking time bomb, if you cannot rip out the IEM plug in time you're going to cop an ear full. But, one must understand when the volume bug occurs it doesn't surge to 100% volume instantly, it goes up gradually in increments about 6-8 steps at a time with a short delay inbetween. So you will hear it slowly creeping up further and further ., it's not a sudden shock (((BAM IN YO FACE BOI)))) to 100% from my experience but more the volume getting stuck in an upwards motion and not stopping.
All I can suggest is to use an amp and bypass the headphone out, as you can achieve better sound quality anyway doing this with DX50.
Is that the answer? No, no it isn't but it sure as hell defeats the relay switch problem and volume bug.
I gather you own a DX50 that's why you're so concerned?
Regular little shocks act like a big one with time.
I was planning to buy ibasso... terrified by this post.