After re-reading my post, maybe I should say pinging starts AFTER pre-amp goes thru start up and is no longer muted, i.e, when pre-amp is muted, no pinging, when pre-amp is active, pinging is heard. I've swapped out the 6922s to a new set of NOS Amperex and its still there; now on to the 6V6s (which don't have many hours on them).
Pinging sound from Preamp
I just re-arranged my system, and you got it, the audio gremlins have struck. Immediately after start-up mute cycles off on my BAT VK3i, I hear a rhythmic "ping" from the pre and through the speakers. After starting CD, I cannot hear it, then after a while (30-45 min) I start hearing it through speakers over (lounder than) the music (which is at a fairly low volume). When I mute the pre it goes away, and it is present regardless of source selected (even if source is shut off). Any thoughts?