Guitar Amplifier Electronics: Basic Theory

Guitar Amplifier Electronics: Basic Theory

Richard Kuehnel

Our new book uses these calculators to design preamp stages, cathode followers, tone stacks, power amps, phase inverters, negative feedback, and power supplies.

calculatorLaunch me!

guitar amp long tailed pair circuit

What does this calculator do?

The long-tailed-pair phase inverter with negative feedback from the output transformer is one of the most ubiquitous architectures in guitar amplifier electronics. A signal from a tap in the output transformer secondary drives the feedback input to the phase inverter to counteract the amplified signal. The resulting closed-loop gain, measured from the phase inverter signal input to the speaker, is less than the forward, open-loop gain without feedback.

The calculator assumes that the resistance 2(RK+RT) is much greater than RP.