Artisan 15 cathode biased?

[The Wooj]

Hi people. I just got my artisan 15 combo on Saturday and having had a good play with it I'm loving the sounds it's got. I do have a couple of questions though. Is it cathode biased? And what valves have others put in it that has improved the tone? I have this unquenchable desire to tinker with my amps as I think we all do! Any help would be much appreciated.
Just on another note, my boss sd1 drives the gain on this thing so well. Might not need to save up for an OCD pedal.

[KKND]

http://thetubestore.com/blackstar-artisan-15.html

[The Wooj]

Thanks KKND.

[KKND]

Sure any time. Out of curiosity though, what brand of tubes are on these Artisans?

[The Wooj]

Sure any time. Out of curiosity though, what brand of tubes are on these Artisans?

It's all EHX apart from the two 12ax7's which are sovteks. As it's a self biasing amp I think I'm gonna buy a full new JJ tube set and drop it in and keep the EHX set as a back up in my gig bag.