Hi.I'm new to this forum.I got my LDmk3 last year and am having a great time tube rolling with it and learning about tubes but yesterday i got a pair of old Tesla EF95's though the post.There seems to be a microphonic issue with them as when i tap any surface near the amp i can hear it clearly through the headphones and when i switch the amp on one of the valves lights up brightly for a second but they are performing fine,in fact they sound exellent.I brought these as NOS but they were very cheap at $7 for the pair in original boxes.Maybe this is a common problem with Tesla's.Should i be concerned,is the valve on its way out?
