yet another tube preamp recommendation thread

Don Sachs here.  To be fair, I have sent the person above a whole new power supply board for the Khozmo attenuator.  If that doesn't solve the popping we will source a new khozmo board because there may be a bad relay.  I have probably 100 khozmo attenuators in the world and only have seen one or two with popping issues.   I am taking care of him even though it is a used preamp.  As for placement, the preamp couldn't care less.  It is probably microphonic tubes.  The preamp is not microphonic.   

If the Sudebaker comment was directed at a preamp, it was made with NO knowledge of the situation.  Guy contacts me that he has bought a used preamp of mine and it is clicking on some volume settings.  He is third owner.  People flip gear, it happens.   Shows me photo of inside and someone has soldered things in there, changing caps, etc..  So I am helping guy out for cost of postage for a part I have on hand.  If it doesn't solve it, I will help him further at little cost to him even though I never even made the sale.  I would say that is not a Studebaker.  I am here, helping a guy who bought a used preamp that was hacked up by someone else.   He is not orphaned.