Sansamp Issue

[XPAULUSX]

So i was at practice last night with my newly acquired Sansamp BDDI.

I set it up as a pre amp, so plugged it in through the effects return on my head (Trace Elliot AH300SMX)

Stupidly, i had not noticed that the "level" knob on the Sansamp was cranked all the way up!! ( i never left it like that, i must have knocked it or something!)

so anyway, to cut a long story short, i turned up the output volume on my head, you know just to see how it sounded, as this was the first time i'd had it in a setting where i could be as loud as i wanted!!

anyway, it sounded pretty class while it lasted, but then everything cut out!

i turned everything off left it for ten mins, when i turned my head back on, i was getting a horrible farty sound coming out of it!!!

i thought id knackered my cab, but i set up using the guitarists head and this worked fine!

i then proceded to turn the head off again, left it for ten mins and when i turned it back on, i was getting no power at all, i looked at the fuse just underneath where the kettle lead attaches to the head and discovered that it was blown, i promptly replaced this with an identical fuse, but when i turned the head on again, i had power for about two seconds, then the power fuse blew again.

This is obviously something to do with the power supply or the main amp within the head, however, im not so hot at this kind of thing, so was wondering if any of you more experienced basschatters could tell me what it is i have actually done to my Trace!!! (it's going in for repair as soon as poss by the way )

Paul