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In most cases, amplifiers are biased between 50% and 75% dissipation. We bias the SOY to approximately 23mV-25mV
reading on a DMM.
An example is as follows:
You might wonder why your DMM is set to millivolts and not milliamps – simply, we have a 1 Ohm resistor placed between your
probe jacks and ground to convert a current reading to a voltage reading. That way, a bias current of 24mA measures as 24mV
on your DMM.
NOTE – Only set your DMM to mV for measuring bias on the Son of Yeti. Not doing so may damage your DMM.
Now that you know how to calculate bias, all you need to do is:
1) Follow steps 1-5 on page 11
2) Calculate what bias voltage reading you will set your tubes to (in this case, we will use 24mV)
3) Place your red probe in the top BIAS jack, and the black probe in the COM jack.
4) Turn the bias potentiometer shaft SLOWLY until your DMM reads 24mV
5) Wait 1 minute
6) Recheck all power tube bias measurements
7) Readjust bias potentiometer shaft if necessary
14��
× 65% × 1000 = ���������� 24����
380������
12
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