2. amps-preamps
  3. 170302-99335

120hz hum coming from all-tube system - but only at high volumes

I generally listen to my system at 8-9olcock on the volume dial.  A friend and I were pushing the dial up to 11-12 oclock and a fairly loud 120hz hum would start to appear after a while.

Bringing the dial back down would eliminate it.  You could then pushing it back up and it'd be fine for a bit and then then hum would reappear.

Do I have bad tubes somewhere?  Ground loop that only rears its head occasionally at high volumes?


(System is Manley Steelhead pre, Manley Mahi's mono amps, Forman Elite-15 PFi power conditioner, schiit yggdrasil DAC, Klipsch Forte IV speakers)
otherones

Showing 1 response by audition__audio

audition__audio
1,634 posts
 
First you need to be aware of the difference between a hum and tube/system noise. To me at least the 2 are not easily confused. 

Usually microphonics is a ring or a howl, but to be certain tap around your components to see if the tapping transfers.
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