duhvoodooman
Addicted to solder....
My recently modded Valve Jr. is giving a nasty buzzy distortion on one particular note--between C4 and C#4 (about 270Hz). It's the worst when I play middle C on the G string and bend the note up a half step--horrendous buzzy distortion! A half-step further up or down, and it virtually disappears. I can get the same thing by playing this middle "C-and-a-half" note farther up the neck on the D, A or E strings, too, so it's not string specific. An octave lower (i.e. between C3 and C#3) and it's also there, but to a much lesser degree. An octave higher (C5+), and I can't hear it at all. So it's very pitch dependent, which I would think suggests that it's some kind of harmonic/resonance behavior. In my limited experience with amp modding, this is the first time I've encountered behavior like this.
I thought that perhaps it was a microphonic tube, but I separately changed both the 12AX7 and the EL84 tubes in my VJr, and neither change affected this behavior. Neither did switching between the onboard speaker and an external cabinet, so it doesn't appear to be a sympathetic vibration thing. And it happens with any guitar I use, whether single coils or humbuckers, and with any of the individual or combined pickup selections.
Has anyone here ever run into this? Any ideas on what causes it, and, more importantly, how to get rid of it?? TIA!
I thought that perhaps it was a microphonic tube, but I separately changed both the 12AX7 and the EL84 tubes in my VJr, and neither change affected this behavior. Neither did switching between the onboard speaker and an external cabinet, so it doesn't appear to be a sympathetic vibration thing. And it happens with any guitar I use, whether single coils or humbuckers, and with any of the individual or combined pickup selections.
Has anyone here ever run into this? Any ideas on what causes it, and, more importantly, how to get rid of it?? TIA!
