Maker Factory ELECTRONICS EXPERIMENTS BOX Manual page 257

Circuit 41: FET transistor T1 functions as T2 emitter resistor. The operating point of T1 defines therefore the
gain of T2. The operating point of T1 and thus the gain of T2 is set by the control voltage.
Fig. 3.40: Circuit
40: High pass
from on 5.5 kHz
Fig. 3.41: Circuit 40:
Electronic level control
with large control range
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