Any Jadis Defy 7 MKII experts out there?

I have a Jadis Defy 7 MKII amp. The left channel was distorted so I took the bottom plate off to check the bias. All six of the bias fuses were blown on the left channel and 2 of the bias fuses were blown on the right channel. Does this mean that I have 8 bad 6550s or does it mean the bias drifted to the point it blew the fuses?

Any help would be appreciated.

I have a Defy 7 Mk IV, and have had some experience with bad tubes and blown fuses. The cause of my problems were low quality tubes I purchased new in 2003 labled as Svetlana, wich were developing grid current after only a few weeks of normal use. My best advice is to be absolutely sure to replace the fuses with the correct value and type, and replace your tubes with quality new ones, do not try to reuse them after adjusting bias. I damaged my amp due to impatience and ignorance. (It was my only amp at the time, and it failed on a Friday night. Naturally I rushed to get it back in service with some unpleasant results.) I had the amp repaired and throughly inspected/tested by a qualified technician and in the end it was just bad tubes. The "Tungsol" 6550s currently in production sound good and have proven to be the most reliable of all I have tried, I'm getting about a year and half to two years out of my power tubes with Sonus Faber Electa Amators. I've had the amp for nine years now, and it still plays music...but I keep a solid state amp handy, just in case.
Im no "expert" by no means but have owned a couple Defy7 amps.I would guess its the tubes,replace all them including the 12ax7s and make sure the new tubes are all matched(will be expense hence the reason Im no longer an owner).Also have the amp re-biased by someone that knows what they are doing.If that doesnt do it a tranny is going bad.
I thought I might add that I also replace the 180Ohm resistors with Kiwame 2watt/180R soldered in such a way that if a tube goes bad, the solder melts and gravity works as a fuse. In other words, I no longer solder them through the thru holes, but to the leads about 3/8th an inch from the board. (Four of my twelve original resistors scorched the board during my original Svetlana/not Svetlana melt down.) Im not an expert, but I am committed to long term ownership. (Or stuck with it, depending on your point of view.) At least, with NOS RCA black plate 12AU7, Telefunken 12AX7s, the current production Russian made re-badged Tungsol 6550s, and a Jadis DPL pre amp in front of it, it sounds great.

PS: The DPL works awesome with a variety of solid state "back up" amps.