Problem with system

Last yr I purchased a Schiit Bifrost.  It worked and sounded fantastic for 5 days, then I lost dynamics and clarity.  I ordered another Bifrost  thinking it must be the dac.  But no, it still lacked dynamics, clarity.  So I sent in Bryston amp, got sent a new amp.  Still lacked detail clarity.  Sent in preamp, was told nothing wrong by Bryston.  Ordered Gungnir.    Plugged pre and Gungnir into system, still no dynamics, simply lost detail, dynamics.  Sent Gungnir back for refund.  Of course I switched out speaker wires, even ordered a cheap Cambridge integrated and Dali speakers to troubleshoot.  I tried all iteration with components. Seems to be preamp (bp6).  Anyone ever heard of a componant (in this case Bifrost dac) damaging a preamp?  I’ve been trying to resolve now for a yr. Just ordered bp19.   Thanks