I was playing and all of the sudden....

I had this problem before too, Once when I was running a quad of JJ 6Ca7s.

 

My mistake, photo clipped, although W21 type were fitted from factory.

So the solder that's 2 years old has failed?

 

yes. not sure why though. I'm no amp expert, that's for sure!

 

Could be many things, perhaps the solder didn't adhere to the resistor, or the resistor was doing it's job too well and it should have fused.

Reminds me of a big Mountain bike crash where I tore my shoulder muscle off the bone, the consultant told me ''I was abnormal!!, the collar bone is supposed to break under these circumstances, yours is too strong and now you have no muscle on the end of it to lift the upper arm to a normal position''