2. amps-preamps
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Hum on Tube Amp - Can't find source

I have a hum (60hz) I can hear on my speakers and it happens with my tube monoblocks (either of them).  With or without interconnects, it even happens on either amp (have tried one at a time) with every circuit on the house tripped/disconnected, every other component disconnected from the wall (including the Internet/CaTV line) and no interconnects.  

One amp has it as soon as it warms up whereas the other one is intermittent.

Hum X doesn't solve it, iFi Ground defender either, AVA HumDinger on powerline  doesn't solve it either.

I have replaced the tubes and both amps were just tested at the factory.  Replaced the circuit breaker, tightened every wire on the breaker box, checked and cleaned all connections to ground rod.  Added a hum eliminator to the internet line.

Hum cycles a bit with the tube glow matching the cycles.

I'm waiting on the power company to come check the power coming to the house.

Thoughts?

ervikingo
ervikingo OP
166 posts
 

@wsrrsw tried with Van Alstine Humdinger (for DC) but as described by FVA it only works to solve mechanical noise. I decided to try anyway. 
 

Also tried the iFi plug in things and even an old Tice thing (not the digital clock)  

waiting on a Zen Line Conditioner from Decware. 
 

Tomorrow planning on shutting down the alarm’s cell and wireless sensors. 
 

I went into the circuit breaker panel to confirm ground are properly connected. 
 

Next is taking amps to test at my office. 

what am I missing?

redhouse6
8 posts
 

I suspect that it is the filter capacitors in the power supply. I used to fix tube TVs when I was a kid. 
 

You could also try an isolation transformer. 

ervikingo OP
166 posts
 

Well, I can confirm it is not the alarm (which BTW I have reconnected!)

 

@redhouse6 like a Triplite?

I have a ZLC on order but it takes time to get it.

Ag insider logo xs@2x
cleeds
5,993 posts
 
ervikingo

... Next is taking amps to test at my office. 

I think that will reveal the amps are the source of your problem.

jetter
3,050 posts
 
ervikingo

... Next is taking amps to test at my office. 

+1

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