A persistent hummmm...

Sorry - in the list of things I said that I tried, the cheater plug should have been first. No luck there.

I have changed the inout tubes a few times, and that doesn't seem to affect it. I don't know whether there are quieter versions out there ( I used JJ 12 Au7's). 

I think the that the power, which comes from the PS Audio Power Regenerator is pretty clean, at least according to the scope built in to the unit. But something is off, clearly...

Thanks for thinking with me...

David

So, on my (so far) futile diagnostic journey, I disconnected all input to the amp. and then unplugged them. The amp, with nothing plugged into it, or even sharing the same wall plug, continues to hum. I have to say the builder, George Counnas of Zesto, has been very accessible and involved with my process. Besides taking the amp back and checking it out, he has called me more than once to check on my progress. I think he has made an honest effort to help. 

I"m not a technical person, so trusting my gut is not really a substitute for process, but my suspicion is that the culprit is somewhere in my house. 

I really appreciate that a number of you have tried to think with me.

David

Yes - I sent the amp out to the manufacturer/designer, and he said he didn't get any hum at all. Of course, i don't know what speakers he uses, and you are right - the efficiency of the speakers certainly exacerbates any hum problem the amp has.

I think I may need an electrician who is mindful of audio needs. Most are not, I'm finding.

Hi all,

My Zesto amp is pretty new - a couple of years old. The hum was there from the start, but my previous speakers didn't emphasize it as much as my new speakers do. As a few folks have said, the efficiency of horn speakers has a down side.

The sound comes out of the speakers, AND if you put your ear to toe back left of the amp (where the toroidal transformer is), you can hear it buzzing there, too. 

I like (well, at least as a path) the notion of unplugging many things in the house - I've already done so in the listening room itself. My listening room was a "found" space - it was an old three sided porch on the side of the house I enclosed and made into my room. It lives on top of the boiler room in the basement. That room has an oil burner (with a pump for the oil), and since it is baseboard hot water heat, it has multiple pumps to circulate the heated water throughout the house. I wonder if those pumps are throwing junk into the line?

Anyway, you have inspired me to search for the equivalent of the coffee maker that a poster found in his house. The source is out there...

Thank you for that distinction. I can hear the buzz in all three drivers. The pitch changes a little, of course, but it is about equally loud. And, as I mentioned earlier, there is a buzz at the transformer itself.

This gives me something to talk to Zesto about. Thanks for that.

Inspired by tales of Glade air fresheners and coffee makers, I started to go through my house. I removed all of the Xfinity "pods" that are -lugged directly into a socket, and meant to distribute the wifi signal over the house more evenly. No luck. I also took off all LED nightlites. No luck there, either. I'll keep trying, and talking to Zesto.

Thanks again