Hi everyone,
Recently, I started seriously playing guitar again and fulfilled a teenage dream by buying a Bogner Uberschall.
Since this is my first tube amp, I noticed that it produces a sort of mechanical vibration when I play at certain volume levels. The vibration decreases as I lower the volume.
I can’t clearly tell whether the sound comes from the second power tube from the left, or from the output transformer located just behind it.
The video shows a quick test with the amp connected to a Two Notes Torpedo Captor X (the fan noise comes from the Captor X).
I gently tapped each tube with a pencil while the amp was running, but I couldn’t hear any obvious ringing or microphonic resonance at the output.
My questions are:
- Does this sound like normal behavior for a high-gain tube amp?
- If not, what would you recommend as a first troubleshooting step?
Thanks for any help!
PS: For context, I’m a hardware engineer, and of course regarding electronics safety, I apply the exact same precautions and high-voltage safety practices that I follow in my professional work.