I run both the BHK pre and the BHK 300's and I have this tube rush noise. I had it pretty badly with one pair of Amperex 7308 tubes on the pre that just didn't age well (started out quiet enough, but got really noisy in aboout 6 months' time). A change of tubes markedly improved things, but there is still noise. When the music is on I have no awareness of this tube noise, and these BHK pieces deliver a lot of musical enjoyment for me, so I think it is all just fine. That's my experience.
Slight speaker white noise from hybrid BHK 300 monos and BHK pre normal?
There is a faint white rushing noise from my Focal Kanta 3s. Left channel slightly audible inches from speaker. Right channel slightly more audible approx 1 ft from speaker. Inaudible when music is playing.
Is this normal for tube/hybrid equipment like the BHKs? In addition to BHK 300s and BHK pre, I use a tube modified Modwright Oppo Sonica DAC. Tubes are NOS Telefunken RCA and Siemens.
Had a similar issue with my previous Audible Illusions L3A linestage. My tube guy suggested the following which successfully reduced the noise floor - though not to silent.
“A flake of cathode material may have migrated into the grid of the tube. Try removing the tube and tapping it firmly on a table top, then reseat it and burn it in for 12 hours and the noise should be gone.”
I did this to all my tubes but still hear the white noise, albeit faintly. Is this a characteristic of tube/hybrid vs solid state which is dead silent?