Thanks gents. @Polygonhell i think youre like me on a sensitivity to noise scale. Youre probably better at blocking it out though and just enjoying.
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When I need to adjust the hum pots I will use my IEMs as they let me dial it in a lot better than with only the Utopia. Obviously if it is not related to the power tubes, the null pots won’t change any other noises popping up like a ground loop that I did have pop up when adding a component with a grounding issue.
@Souldriver I also am very sensitive to noise and have spent more time than I care to in identifying the culprits 
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Probably a good move. I didnt know dna stuff had hum pots.
Well i am glad i tagged you too then! A certified Hum Hunter!
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The stratus has ac heaters, for DHT’s with AC heaters they are pretty much unavoidable, your running an AC signal across the cathode of the tube, if the AC isn’t perfectly balanced at the central tap, you get that 60Hz signal directly on the output, hence trim pots.
EMF can also cause 60Hz hum and ground noise.
FWIW I also can’t entirely tune out the 60Hz hum on the Egoista with the trim pots, it’s at similar levels. The simplest solution for the Utopia is to use an output attenuator. I added one to my hybrid amp (not that it needs it to be silent) to give my more usable range on the stepped attenuator.
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Starlet was noise free with Utopia and Stellaris is noise free with Utopia and Mysphere 3.1, cave-like quiet, I sometimes check to see if I have the damn thing on. I sit right next to my rig so I can hear the faint hum of my gear but nothing translates through to my headphones.
The only time I had noise issues is very similar to what @camus pointed out already, either an external source of interference, bad tube or a rare 2a3 set I couldnt null out fully (Linlai 2a3). My biggest extraneous noise issues were solved by getting rid of my Holo May, moving the SMPS for my router and the power conditioner sorted out the rest.
Im pathologically sensitive to extraneous noise with my setup so it pleases me to no end that its extremely quiet.
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Sounds like the EC. I pause it for calls and forget i turned it on until i see the power light.
To peel back the curtain a bit someone noted they liked how the DNA amps sound but he thought they were noisy. I thought that was odd since its recommended for the Utopia and that will pick up most things. He heard it at an Axpona show and thinks it was either show conditions or maybe Donald made some revisions to since then.
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That’s huge assumption given his only experience was at Axpona, everyone hears differently and some think other tube amps don’t have a noise floor because they can’t hear it with the music playing. Surprise it’s still there in the background!
Also, Donald wouldn’t make a revision and release with a higher noise floor. Not sure where he got that assumption from, even on the prototype amps Donald send’s out he ensures they are up to his standard. In other words they are 99% complete amps with minor part change which the majority of folks would likely not notice.
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There is no way you’d hear the noise floor on the one I had with ANY ambient noise.
I’m lucky enough to live in an area where there is 0 traffic or neighbor noise, and the loudest thing in my house during the Spring is the frogs at the nearby lake.
As I said I had to listen for it and concentrate to hear it. I couldn’t have heard it in those conditions.
Maybe a bad tube, or something external interfering with it, hard to guess.
The big advantage the EC has from a noise standpoint is the separate power supply.
I could hear slight noise from my studio T when the PSU was right next to the main case, move it 1ft away and I can’t hear it anymore.
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I will say on my EC. I had them 3" apart and still nothing. I know some old moth stuff was said to have noise but it seems since then Craig made revisions and took any noise personally.
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