Willemj 9-25-2017If you are saying that the PrimaLuna amp and preamp were being used together when the problem occurred, I’m not sure how a medium powered tube amp whose output transformers are incapable of passing DC, or even passing frequencies of several Hz or more without attenuating them significantly, could have "destroyed" the speaker. At most I would think a tweeter might have been damaged as a result of severe clipping. Especially if the clipping were allowed to continue for a significant amount of time, for example if the system was running unattended.
I have just found back a letter from another user who reported that a failed capacitor in his PrimaLuna Dialogue preamplifier destroyed a Harbeth SHL5+ speaker....
PrimaLuna talked this man into buying a PrimaLuna power amp as well. That is all I know.
In any event, it certainly sounds like a different situation than the OP’s, at least if the PL amp and preamp were being used together when the problem occurred.
Regards,
-- Al
P.S: Ralph (Atmasphere), thanks! I of course agree with everything in your post, which refines and elaborates on some of the things I was getting at in my earlier posts.