1. Connecting the negative pole of the multi-meter to
the zero ohm speaker terminal, and find out the test
point behind each EL156 tube.
2. Using a small screw-driver to slowly adjust the
adjust switcher, till the test voltage reach the
0.85V
Repeating the steps above for each power tube. Please
keep in mind for that the bias voltage of each tube is
best at same level.
Congratulation! You just updated your Jasmine Piano
SONATA EL156-SE Tube Amplifier!
Step Three: Adjusting Bias-Voltage of the Tubes