Rig Catastrophe

[Dapper Bandit]

So, up until very recently I've been using a Marshall VBA400 into 2 Marshall MBC115 cabinets. Worked fine for a couple of years then the amp started distorting at low volumes. Sent it to a tech immediately and apparantly there were a couple of dirty points and he swapped a couple of tubes round. Worked perfectly from there and he also noticed that the ground wire had become disconnected so he re-attached that.

Fast forward about a year to last week, we're practising on Wednesday in preparation for a gig on Friday night. Halfway through our practise one of the speakers blows. Most annoying but it's not the end of the world, I can run on one cabinet and stack it on top of the broken one (which was not connected) to get a reasonable on stage sound.

Friday night rolls around and on the 3rd song of our set my other speaker blows! There's no way I can DI my signal as the PA used in the club could not take any more inputs (drums mic'ed but we ran our amps slightly louder than we would have with a DI but still not even pushing half the volume our amps were capable of). Sound guy suggests I plug into a spare 4x12 Line 6 cab that's on stage, it's a 4 ohm impedance and everything seems to be fine, finish off the rest of the set with an admittedly tinnier sound but nothing notable.

However, come load out time when we pick up my head everyone notices a horrible electrical burning smell coming out of it. At no point was the amp turned on without being attached to a cabinet so I'm not really sure what the issue is.

Now here comes the point of my ramble: any ideas what could have happened with my head? The cabinets I'm not bothered by as they were pretty cheap and nasty and I was getting round to replace them but I'm wondering if it's worth trying to get the head fixed?

We've got an upcoming gig early next month and I'm looking to replace the lot and then best case scenario have the VBA400 as a backup head. Local store has an Orange Bass Terror 500 that looks pretty nice but no cabs to go with it. I know that vertically aligned speakers are more efficient and I was looking at the Ashdown VS 212, which appear to be designed to be vertically aligned and ported (very similar to the Barefaced Super 12s) and I was wondering if anyone had any experience with them or could vouch for their quality?

Sorry for the incredibly long post, looking forward to anyone's help!

[Monckyman]

My very vague guess would be your output transformer has gone, and was spiking and thus cabkilling.
I saw an Ashdown ABM kill all 8 drivers in an 810 once.
Our tech fettled a fuse on the input of the 810 from then on to prevent said spikes.
Hope you get a cheap fix.
MM

[Mr. Foxen]

Sounds like you need your amp gone over properly, cleaning some points and tube swapping sounds like a low budget job. If the amp had a problem before, it might just have not been putting out the power it could have, and sorting that could give you the juicce to blow cabs, and when a cab goes, its impedance also goes wrong, either way, so could have taken something with it. If you amp does burning smell, it needs to be properly looked at.