My Granite monoblocks took both the KT88 and EL34. I could never get them to sound right with the EL34, and am pretty sure it was an issue of bias, though I didn't pursue it too much.
My Jadis DA30 and DA60 integrateds can also use either, and I strongly prefer the EL34 in both of them, provided the right driver tubes are used to address the loss in low frequencies that occurs otherwise. In a nutshell, the EL34 really walks away from the KT88 in the midrange, giving both amps a far more musical and natural presentation.
My Jadis DA30 and DA60 integrateds can also use either, and I strongly prefer the EL34 in both of them, provided the right driver tubes are used to address the loss in low frequencies that occurs otherwise. In a nutshell, the EL34 really walks away from the KT88 in the midrange, giving both amps a far more musical and natural presentation.