And you are not wrong. there either.
Perfect, thank you!
Well I originally thought somewhere along the way power wasn’t reaching the tubes, but I guess it’s something else. Those tubes do look a whole lot brighter.
I shaded the area before taking the photos, so the filament glow was clear. I think your photos were just in brighter ambient light so the filaments did not stand out so much from the background.
they are in the signal chain to impart "tube sound" into the signal, and the current mirrors are there to linearize the output of the tubes beyond what you normally see in tube preamps, so they are adding a very slight "tube sound" without adding enough even harmonics for you to pick it out as distortion.... i'm sure the resulting change is measurable on test equipment, but so subtle that in a listening test you would hear a difference, but not be able to pick out what the difference is.
I feel an opportunity to be educated here. Why would they want to remove the phase shift? Surely it would be near enough equal for both channels to not be noticeable anyway if they just used Cs or Ts?
i wouldn't be surprised if some ad brochure for this preamp actually said it's a "DC coupled tube preamp" or something like that.... "audiophiles" are a highly opinionated bunch. some of those opinions are valid, but i've seen a lot of downright "snake-oil" stuff out there (very expensive snake-oil). one company makes preamps with a huge 50 lb power supply because their claim is that even for a preamp, the power supply needs to have an impedance of less than a milliohm or it will degrade the sound somehow.... and don't get me started on the "cryogenically decrystallyzed" audio cables or the "no electrolytic capacitors in the signal path" nonsense.....
