I just got a set if KT77 tubes to try in my Jolida 302brc amp. The "easy bias" lights do not come on when I adjust the bias pots. The manual says to use multimeter and adjust bias to 400 - 450 millivolts but the pots only go up to about 180 millivolts. I am a little confused here. Some on-line resources say bias at 40 - 45 mv, that's 1/10 what the manual says.
The original EL34's will bias just fine. I called the company that I bought the KT77's from and they said that the range of the bias pots was not enough to accommodate these KT77's so I may have to send them back. I'll call Jolida and see if there is a way to modify the amp to accept the KT77's.
I called Jolida and Mike said that the KT77 should drop right in and work very much like the EL34's. He thought the tubes might not be good. They were supposed to be new tubes. I sent them back and will see what the seller says.