RGA
Super Member
It does not matter if you use separate preamp or not. Audio signal still passes ALL tubes.
This is interesting I would have though the preamp would bypass the integrated amp's preamp stage - you wonder then what the "switch" on the front of the integrated is for. You plug the preamp into the preamp in section and I was under the impression the switch then takes the preamp signal and passes that preamp stage to the power amp section of the integrated and that the 12AX7 while on would not have signal fed to them.
I tried out three preamps recently and all three had very different sound through the 219IA - and presumably the additions would add noise - but none and even with 100dB sensitive loudspeakers.
Learn something new all the time here.
Cheers