Metropoulos Forum

Hi, I built a 50 watt kit a few years ago and it's been working great till now. A few weeks ago the sound it made I could only describe as a farty guitar tone. When it happened, a quick couple of taps to one of the preamp tubes and it went away. A few days ago it came back after hauling it to a buddy's house and back. Is the tube dead, or did something come loose? thanks

A quick clip of what I'm talking about:
https://soundcloud.com/nikarc/amp-fart

Try it with a new tube.