Ghost notes/ unpleasent overtones

[doctracey]

Anyone out there that has run into this before? It is most prominent from the open G string up the next octave and a half or so. With harder picking becomes much worse and is an unpleasant tritone-ish interval.

The amp is a 6505+ that I just fixed a bad DC heater section on.

A long time back before I was working on amps I heard the same thing on someones 1960's AC30 at a jam.

Thanks in advance for any suggestions!

[John_P_WI]

Bad filter caps, not enough decoupling, bad grounds, bad grounding methods, bad lead dress just to start...

[JoshBernstein]

I had this issue recently and it took me a solid 2-3 months to figure out. I even rebult the amp with all new parts with no effect. Turned out i had 2 bad cathode caps on the v1 triode in a row. Could also be cone cry or voice coil rub, had that happen to me recently as well.

[xtian]

I had this issue recently and it took me a solid 2-3 months to figure out. I even rebult the amp with all new parts with no effect. Turned out i had 2 bad cathode caps on the v1 triode in a row. Could also be cone cry or voice coil rub, had that happen to me recently as well.

JoshBernsteinKendrick is king of ghost notes!

[Phil_S]

I had something similar with a pair of Sovtek EL84's. But it was only for one specific note, not a range. On closer inspection, tapping the tube when held next to my ear produced an audible vibration. I believe there must be something loose inside.

[doctracey]

I've tried other speakers, still there. The power stage is clean plugging into the return.

It's on both channels, so I'll look around V1 and the cathode caps, wouldn't have thought of those first...