Diagnosing/Eliminating Speaker Rattle (or Buzz)

[Chuck H]

Mystery solved...sort of. Ran two different tube amplifiers (an Emery Superbaby & a Gilmore Ardmore, both about 4-8 watts) into this speaker/enclosure & everythings sounds OK...pretty much par for what one might/should expect from a smaller, low-end Weber Alnico speaker.

Now I'm somewhat curious what might be the cause of this 'echo-like' buzz/hum emanating from the amplifier. Turns out it is slightly audible even at lower volume but more pronounced when the volume level is turned up.

Peculiar that it occurs only at a specific area of the guitar scale...the natural 'harmonic' areas.

Running this particular amp through several different enclosures pretty much solved/eliminated the first problem but left a new one in its wake.

So, you used other amps with the enclosure. The last sentence suggests that you also used the amp with other enclosures. Is this correct? So did you try the amp with other guitars too? Just the A and E strings at the 12th fret is peculiar. If it's tone specific, then why not 7th fret A string, second fret D string, etc.?. So could it be the guitar? If you tune the guitar down a half step does it still happen at the 12th fret or does it move to the 13th fret?

If it IS the amp then the two reactive tones isn't typical of an oscillation issue. The last time I experienced something like this (specific tone fretted in a specific place causing a rattle) I hunted for a cabined problem for a day. This was a combo amp and I found that with the amp out of the cabinet the problem stopped. But with the amp sitting right in front of it returned. So the cabinet was affecting the amp rather than the amp affecting the cabinet. It was VERY frequency and resonance specific occurring on only one note fretted in one place. Long story short... It turned out to be a cold solder joint in the preamp.

[Justin Thomas]

Hey Chuck,

overdrive fixed it 7 years ago... D'oh!

Justin

[Chuck H]

Ha! Just reading along a thread that showed new posts and didn't pay attention. And I don't know that he fixed it or not.?. I hope so, but sometimes projects get shelved for a long time when the problem appears to be unfixable to the poster. Still, overdrive's last activity was almost four years ago. So I'm just talking to the wind. Or not. It's good to resolve threads with either a definitive repair or at least a comprehensive overview of diagnostics so that future readers can benefit.