A final update: In november i took it to the store where it was bought. The store clerk agreed that it would be prudent to have it tested. In fact he believed that their demo-model had undergone a similar change, to what i described, within the past couple of months. But he had previously disregarded it as just his "imagination"/remembering wrong. Not unlike myself, as it was a subtle difference.
But it was sent in for repairs, just to be safe and know for sure.
A couple of days ago it finally came back, after near as makes no difference, 2 months with no information what so ever in the mean time. The final report said that something had been soldered, and it was now repaired. But no specifics about what had been faulty. Logic dictates that something must've been wrong, either measurably or visible on the circuitboard. Otherwise i guess they wouldn't try to fix it, but instead sent it back with a "nothing wrong, quit wasting our time" note attached (as would be reasonable had it been the case, i might add).
I'm happy that my beloved synth have come back. That is, untill i switch it on...
Within minutes the filter start emitting a strange scratchy noise at note on, which rapidly escalates in strength while the intended sound of the synth become erratic and diminishing. Next thing i know, there's no sound what so ever - nothing i can do to get any sound.
I switch it off and back on, which restores it to normal behaviour. Or so i thought...
When i turn the BruteFactor past roughly the 1 o'clock position, something in the circuits start emitting a low pitched, out of tune, (60-65Hz ish) sawtooth-like drone. It's unaffected by the gate, and note information. But the filter cutoff does remove frequency information. Tweaking the BruteFactor reveal it disappears once below 1 o'clock setting, and reappears above.
The droning is so powerful that it completely drowns out the oscillator waveforms - even all of them at full tilt at the same time, and the noise source, is a distant whisper behind the droning. The drone's frequency have no correlation to any of the oscillators parameters or function, as far as i can tell.
And before americans think that roughly 60Hz noise = electrical noise from the wall socket. I'm from Europe, our sockets supply 50Hz, which is a noticably lower freq, and any such noise would sound VERY different.
Soon after the filter starts scratching again, and shortly after all sound (incl. the droning) disappear.
The behaviour is repeated 3 times within 30mins, each time the same faults.
Today i took it to the store, disappointed, and explained that whatever they had done, they had just made it worse. I would've liked an explanation as to what the original problem was, as well as whether or not the escalation was caused by the "repair" or was just the original problems "natural" evolution. They offered to attempt again to repair it, but with a heavy heart i asked for my money back.
This total outcome, as well as the many issues people describe in this very forum (and many others), have led me to believe that Arturias components are of sub-par quality. No doubt they made the best sounding and most inspired synth of the new batch of cheap analogue mono synths. And they were 1st (disregarding DSI and Moog doing their kinda seperate thing). But somewhere along the line they must've cut some corners to keep costs low or something.