Good question, not stupid at all
on, no signal needed, 60 hrs
brent jesse
advises burning new tubes in for 60 hours, before listening, then judge how they sound.
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my last order, I had working tubes (unmatched, but wanted a new matched pair of 6sn7’s that did not look absolutely identical to my adjacent 6sl7 (I had blown one I somehow put in the wrong socket position after testing them).
Received the new tubes, compared to existing some magic was gone, burnt in 60 hrs, still didn’t like them, returned.
bought a matched set that cost less, full credit, and refund for the price difference balance due. I paid shipping to return them of course.
Magic returned!
That’s the reason I recommend buying from Brent.