You have to burn in your connectors, plugs and spekaers too into the new and quality, sorry, thats my experience in 35 years.
Queston On Burning In A New Preamp
I'm in the process of burning in my new PS Audio PMG preamp. I simply have my CD player in a loop, repeatedly playing a music track. However, I don't have my power amp turned on as to not drive the family crazy. My question is, does it matter that the power amp is not on or does the preamp react differently when feeding a signal to a powered up amplifier?