Can someone please enlighten me on the following.
I have a preamp that uses 2 X 12AT7 and 2 X 12AX7. I just purchased some used Telefunken 12AX7 and when I switch on the preamp, none of the the tube flashes. Previously, when I was having Mullards 12AX7 in place, one each of the 12AX7 and the 12AT7 flashes. Why does this happen and does the flashing indicate the condition or quality of a tube?
Thanks.
I have a preamp that uses 2 X 12AT7 and 2 X 12AX7. I just purchased some used Telefunken 12AX7 and when I switch on the preamp, none of the the tube flashes. Previously, when I was having Mullards 12AX7 in place, one each of the 12AX7 and the 12AT7 flashes. Why does this happen and does the flashing indicate the condition or quality of a tube?
Thanks.