Djohn….
My comments relative to tube types would be the same with either gain (12AX7 or 12AT7)
if you need more info pertaining to the Herron, let’s start a new thread or move to PM and keep this thread on topic.
Signal tube versus power tube, sound impact?
My mono block has eight KT 88 tubes(power tubes) and six smaller signal tubes. I'm using the stock tubes that came with each Mono. I think they are JJ tubes.
Rather than replace them all would it be best to change out the signal or the power tubes? Not sure how good the JJ tubes are but I hear they may not be the greatest.