This elaborate mixer is from an Electronics Today International from the 80s. Operational amplifiers are common and resistors with no value determine the gain of the amplification steps.
This phase shift oscillator generates sinusoidal signals in the audio range. Frequency depends on...
We obtained this circuit in an English publication in 1983. Equivalent operational amplifiers can...
The figure shows how to implement an amplifier with gain 10 using the operational amplifier LM41....