• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Help! Tubeamp makes fast beating noise

Hi to all!

My Mastersound 845 compact is making funny noise when on.

Noise sound:
-fast beating, like heart beating but at 4/5 beats a second.
-low level- probably 50-60db not more
-Comes from both channel

What is it and what can I do about it?

Thanks!!!
 
IF it has feedback, swap the leads from the OPT to the feedback and speaker.

If no feedback, then look to the power supply for issues.

Audioasylum posts indicate the manufacturer will send you a schematic. I would start there.
 
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The amp was always quiet. This motorboating noise started about two days ago, so it must be as you wrote a bad capacitor.
I don't trust myself to repair this issue so I'll try to contact a professional for the matter. I have just discovered that there is a tube amp manufacturer in my city (Freiburg) called Wall-Audio. Maybe they can help me further.
Anyway thanks a lot for your comments 🙏🏼