how to adjust bias for kt77 tubes in Jolida 302


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.
winggo

Showing 1 response by josefm

Yeah, you need 'hotter' biasing tubes, I had a GL KT77quad that couldn't make bias too. Sent them back and the replacement quad made bias just fine.
I have an older 302 and the manual says 35-45 mV. for EL34 types, so not sure about the newer 302brc.