Audible Hum From Integrated Amp

No expert here.

First, try switching the tubes. If this does not work, try replacing them.

Then, if the hum remains, call the manufacturer.

Call the manufacturer.  Sounds like a bad cap if you can hear the volume being adjusted.

Do you have to have your ear next to the midrange to hear the hum? Most tube amps will make a very low volume hum. Better tubes can be quieter but most likely it is associated with AC to the heaters on your tubes.

If it is loud, my first thought would be a tube issue.

I have quieted integrated amps down by installing shorting connectors in unused inputs as well.

Jerry

Jerry - Thanks...The hum is audible from 10 ft away at 10:00 volume. This is a tube pre amp w/Class D power. I have changed the pre amp tubes with no change  I have no unused inputs...all tied up..

Hmmm.  Then I like Erik's advice.

I think I'll call Rogue tomorrow..it's not a new unit, so I don't expect much, but who knows. Is it worth replacing the power cord? I'm using the stock cord that came with the unit.

Wait, to be clear, do you mean, the hum volume changes based on the volume control, or do you hear the volume control moving, like scratching, when you adjust it?  The latter points to having a DC voltage where there should not be any.

A humm that you hear changing in volume points to an upstream issue.

Erik - I hear the volume control moving when I adjust it. Scratching , as you said, or ticking is a good description.

OP: That’s probably a leaking AC coupling cap.

The longer you wait the more expensive it might be to fix it.

In tube circuits there’s a high voltage bias on the signal, 100V or more, but the AC component is very small, typically under 10V peak to peak.

There should be a cap before the volume control that removes the high voltage DC so the volume knob and everything after only see the small voltage AC. When the cap breaks down and allows some or all of the DC, the volume knob starts feeling all that voltage, and that’s a bad thing. :)

Much thanks Erik. I'm going to reach out to Rogue tomorrow to discuss.

Thanks for all the input and suggestions..I ended up swapping out the power cord for another that I had in the house. Definitely reduced the hum.