Tubes getting black ..

[elektriber]

Hello Electribers ,
i got my EMX for almost a month , weird thing is that the tubes are getting a black strip right where the top metal bit starts.
I've contacted Korg and here's what they said :
"Hi
This can happen on valves with prolonged use. It’s basically getting hot and it’s a build up of heat that is leaving the burn mark. You can leave it as long as the valve is still working but over time the valve will fail so it might be worth replacing the valves now rather than waiting for it to break."


Then i've informed Korg that this is a brand new electribe and here's their reply :
"That is true.. it’s not the best scenario. The tubes aren’t made by Korg so we can’t vouch for their quality but we would expect them to last longer…"

I understand this is not Korg's fault , funny is i've contacted the shop from where i've got this electribe and still no reply whatsoever... :\
Is this normal to happen with the Electribe Emx?

[Ruso]

Well you should upgrade tubes anyways