I put the KT120s back in, and they were indeed set all the way down... way below the window. Put the KT150s in again, still set bias screw all the way down, and they climbed to the same beyond-the bias marks. Just searched the manuals, and both ref 75 and 75SE are to be set to the same 65mV.
KT150s in Audio Research Reference 75 (non SE)
Hey all. Need some advice.
I've just dropped in KT150s into my Ref 75 (non SE).
I purchased "perfect pairs" from TheTubeStore.
I cannot bias them. They are all too hot. There are a couple (of the 4) that if I turn the bias pot all they way down will get very close to the bias range (per the needles). There are another two that even with the pot turned all the way down are reading past the bias range and the needles are about 7mm beyond the bias range.
Two questions:
1) Am I doing something wrong?
2) Will it hurt anything to run this a little over the ideal bias range, or just shorten the tube life? Will it impact sound?
I thought KT150s were drop in for KT120s. Am I wrong?
Thanks!
I've just dropped in KT150s into my Ref 75 (non SE).
I purchased "perfect pairs" from TheTubeStore.
I cannot bias them. They are all too hot. There are a couple (of the 4) that if I turn the bias pot all they way down will get very close to the bias range (per the needles). There are another two that even with the pot turned all the way down are reading past the bias range and the needles are about 7mm beyond the bias range.
Two questions:
1) Am I doing something wrong?
2) Will it hurt anything to run this a little over the ideal bias range, or just shorten the tube life? Will it impact sound?
I thought KT150s were drop in for KT120s. Am I wrong?
Thanks!