2001 bad cat black cat, vibrating sound

[01bcat]

I'm getting a vibrating sound after certain low notes or chords. I don't believe it to be a tube (changed out them all). It sounds like a blown (or going to blow) speaker, but it is coming from both (2x12 combo). It has the original caps - they still say Matchless on them.
Could I have a vibrating / microphonic cap?
Thanks for any and all suggestions...

[mikeboone]

Try another speaker cabinet first to isolate the source of the noise.

You can find out two things from this.

1. The obvious... whether it is your speaker(s) or not.
2. If there is an issue in your amp that is sensitive to vibration at those frequencies caused by the proximty of the speakers.

I had a Mesa Boogie Mark II 1x12 Combo that was making some odd noises at loud volumes (aside from my guitar playing). I took the chassis out and looked it over. I found a few fractured solder joints. I resoldered them and all seemed well until I put it back in the chassis. It made more noises, etc, etc...

The moral of the story is each time I thought it was fixed, I would put it back together and the problem was back. The vibration from the speaker was triggering the problem. So after that, I placed the chassis on top of the combo cab to test it until I found the problem.

[01bcat]

thanks Mike

What exactly was the problem with the boogie?
I know it isn't the speakers. I am wondering since I ruled out the tubes, if it is a microphonic cap etc that someone else might have experienced? It is a combo, and I plan to use it as such, and it has been fine up until this point. Using another cab will just move the vibration away - so odds are it wouldn't happen. I want to solve the problem with the existing pair.
I will at some point pull the chassis out and "chopstick" it.
Thanks for the suggestion