I tried a pair of Telefunken 12AX7 my friend brought over, and we both liked the stock tubes best, also. It was kind of surprising, as he has tried A LOT of 12AX7, and thinks the Telefunkens are best. Still, the pair he brought over may not have been the best(we pulled them from a Sherwood amp he brought over), so we were unsure of their lineage.
Someone once wrote to me that the Telefunkens made a nice difference in their JOR. Another wrote to me that 5751 improved the sound. But, again, the originals sounded best to me so far. Not that they are the best...
I doubt you would need to rebias, I didn't. But, I didn't check to see if it affected it either.
Someone once wrote to me that the Telefunkens made a nice difference in their JOR. Another wrote to me that 5751 improved the sound. But, again, the originals sounded best to me so far. Not that they are the best...
I doubt you would need to rebias, I didn't. But, I didn't check to see if it affected it either.