@earlflynn
Sorry, I am just seeing your question. My point was exactly what I said: that the tube in the Border Patrol Dac is in the power supply and NOT in the signal path. If you read the post immediately preceding mine, you would see the posts I was responding to.
I happen to agree with you that it is a terrific dac. I certainly meant no offense and had to look back in the thread to see where you had posted that you might have one for sale. While I dont see how my post could have caused you alarm, no offense was intended. Just stating a fact about the tube’s purpose in the dac.