Tube Question - Significance of Tube Noise at Listening Position

OP - I recently bought a pair of Ray's Select 12au7s and was favorably impressed. Also had a noise issue with amp but turned out it the tubes were not the culprit. 

Last month I picked up a used Primaluna evo 400 power amp as a backup while one of my SS monos was in the shop. Upon hooking up the 400, there was notable noise from both speakers when no music playing, a low frequency static audible up close and higher frequency "squelching" akin to Morse code which I could hear from listening position about 11-12 feet away. The amp is fairly new with low hours on the tubes, but I removed and reseated all the input tubes, rotated their positions, inspected pins, etc. but no effect on noise. I then replaced the two stock input stage tubes with Ray's select 12AU7's which provided a noticeable bump in sound quality (improved bass extension and tonal depth overall), which for me was easily worth the couple hundred bucks they cost. However the noise remained. 

Was beginning to think that the amp itself was simply defective and was considering taking it to a local tube shop or shipping to Upscale Audio to have checked out. After some more troubleshooting finally located the culprit: the cheap switching power supply for my Roon core, a dedicated Dell Optiplex 3050, which is separated from the amp by 3 components and 4 cables. I bought a 19-volt LPS from Small Green Computer, plugged the Dell into it and noise disappeared. So if you have any switching power supplies in your signal chain  worth checking those out to see if they might be the cause of your issue.

@12many I had the BHK Pre in my system for over 2 years.  No matter what tubes I had in the Pre, there was always a level of noise, how noticeable the noise was did depend on the Tubes.  My speakers are also fairly sensitive, that likely highlighted the noise.  I also have found with Tube gear a wall wart / power supply and or a WiFi router or mesh network plugged into the same breaker also can introduce noise to tube gear.  I rolled a lot of tubes in the BHK, NOS and new stock, Gold Lions, Tele’s, Mullard’s, Brimar, Amperex, RCA’s and others.  Both 6922 and 12AU7’s.  The 12AU7 tubes as a whole were quieter.  I no longer have the BHK, have a ton of tubes that I don’t have tube gear for, if interested let me know.  The Tele’s 12Au7 and Amperex 6922 were my favorite tubes in the BHK.  I also have a LTA Aero DAC, bought Ray Reserve select tubes, they are dead quite. Extremely tight, great tubes.  Now, they don’t deliver the same level of “tube magic” as other NOS tubes I have, but they are quiet, provide the most precise highs, mids and bass, what they don’t do is provide the color or romantic, overly warm or holographic tube sound other tubes do.  Sound great, still provide a pinch of tube magic but not like some of the other NOS tubes.  

I also have your BHK pre. The only noise I have had with my BHK was solved with the iFi Silent Power DC Blocker+ Power Filter. I replaced the stock tubes immediately & roll NOS Tele medicals, Brimar CV4003 & Siemens Nickel plates. All are 12AU7’s & all are absolutely silent. Good luck!

Thanks everyone for your helpful replies.  I swapped back in the Gold Lions.  The sound is much better, although the noise is also higher.  It's interesting how it sound better, but with higher tube noise.  The tube noise level does not change with volume and I don't think I can hear it at my seating position.   I ordered some Ray Select tubes to try and compare to the Gold Lions. Really great to get input from people with the same preamp. 

@signaforce - I will check out the iFi Silent Power DC Blocker+ Power Filter.  I already run a Gemini power conditioner and the Shunyata NR power cables - another improvement I did not expect.  

I am posting to provide an update.  I have about 50 hours on the Ray Reserve tubes (12AU7).  At first they were flat and I wanted to swap them out, but they are starting to sound good.  Unforturnaly, I have the room a bit of a mess because I am working on some room treatment (not up yet).  Even so, I am liking the Ray tubes.  Very clear, less noise than the GL, and a bit less than earlier PSVane tubes, but still present.  With break in they are starting to open up with a nice air and holographic. I think these will be keepers - so far so good.   Really looking forward to listening to them when my first phase of room treatment is done.