Yes, sounds like an issue with electrical ground. maybe the ground is not connected at (behind) the wall socket? If so that can be a security risk, let someone check that. I don't think its a fault of the amp.
Recently dropped them multiple times on different surfaces (wood as well as concrete). Either one or both cups came out and now have some dents and scratches, but no cracks. Seems to be an issue not directly related to abuse.
I don't think that this problem with the Lyr still exists... nevertheless I'm sorry to hear that it killed your T70.
For me that way one reason to choose the G109P: it was the only model that had protective relais in the output.
According to several Beyerdynamic reps there was no change to the driver or enclosure besides optical differences when going from 1gen to facelift. DT1350 are said to have wide model to model variations, plus the pads (and their state of wear, i.e. usage) obviously change the sound.
I'm sure there is such a plan. But I would be very surprised if that happened anytime soon... given that the P5 had a 4-year life or so I'd guess the rather new P7 has still at least 1 year left (just an unsubstantiated guess, I do not have any info on B&W product plans)
Thats about what I just wanted to post. I really doubt that the wooden cups were even big enough to produce resonances in the relevant range.Nevertheless wood may have properties that are relevant to this as it has a rather high damping that may prove useful, supporting other measures in the goal of dampening resonances. Still I don't think its a relevant difference (as it is in speakers). They look good for sure though and I like the feeling. Regarding an upcoming new...
I can second that, very nice combination I happily used on vacation. Any physical stress on the cable (pets, running over with a chair etc.)? Sommer cable is of good quality I'd say, so I'm wondering how that came... It might even be toxic... Death Metal anyone?