[bwilson51]

Originally Posted by oldominion

Just for the record, Dennis's 3.1 Preamp and Universal FireBottle SET are the best sounding components I've ever had in my system, and this from someone who's been in this hobby for decades.

That said, I'm on record in these pages that I've also had 60 cycle hum and microphony with my 3.1 preamp. Right now I have two Sophia blue 6sn7's and a Sylvania 6sn7 in the driver stage...I still have hum but microphony has lessened.

The hum is not specific to one input, i.e., it's not the phono preamp; hum occurs in my digital input as well.

Additionally, I, too, have experienced the STARTLINGLY LOUD screech from my preamp upon power up. It's happened at least five times. It's not just a little loud but, IMO, dangerously loud, capable of blowing something. No question. Has nothing to do with where the vol pot is set. Has happened with numerous different 6sn7's and rectifiers.

It does seem to me that the preamp, under certain unknown conditions, might have grounding issues that could be clarified or addressed by Straitwire that would help from a consumer standpoint.

Are you powering up your preamp and waiting a minute or two before turning on your power amp.