Building on Analog Foundations: Op-Amp Cookbook Part 2 Meets Modern Precision

In our last blog, we revisited Ray Marston’s classic Op-Amp Cookbook – Part 1 and explored how its timeless design principles continue to resonate with today’s engineers. Now, we’re diving into Part 2 of the series, originally published in Nuts & Volts Magazine (August 2001).

This installment moves from basic op-amp operation into practical design territory—linear amplifiers and active filters. Although the circuits featured in the article are designed around the classic 741 op-amp, the principles remain directly relevant to modern designs, especially when paired with the low-noise, high-performance devices available today.

Key Takeaways from Part 2

1. Inverting and Non-Inverting Amplifiers

• Marston details classic configurations for both DC and AC amplification.

• Input/output impedance control and offset nulling are emphasized for achieving stability and precision.

• These remain foundational building blocks for analog designers.

2. Voltage Followers

• The voltage follower (unity-gain buffer) provides high input impedance and low output impedance—crucial in isolating circuit stages.

• While the 741 was the reference device in the article, today’s applications demand lower noise, higher bandwidth, and stability at unity gain.

3. Adders and Subtractors

• Summing amplifiers and differential subtractors are shown as tools for audio mixing, precision measurement, and signal conditioning.

• These circuits illustrate how op-amps bring flexibility to multi-input and comparison-based designs.

4. Active Filters

• Marston demonstrates how op-amps can be used to implement Butterworth low-pass, high-pass, and band-pass filters.

• These “active filters” reject unwanted frequencies without bulky inductors, paving the way for compact analog solutions that are still widely applied.

Where Linear Systems Fits In

At Linear Integrated Systems, we design low-noise, high-precision discrete semiconductors that give these foundational circuits new life in demanding modern applications. For example:

• Our LSK389 dual JFET can be paired with op-amp filter stages to achieve ultra-low-noise performance in audio and instrumentation.

• The LSK170/LSJ74 devices provide excellent input stage options for non-inverting high-impedance amplifiers.

• Precision current sources like the J202 and J113 families complement voltage follower and filter designs that require tight current control.

By substituting these devices into Marston’s foundational topologies, designers can push performance beyond the limitations of legacy 741 op-amps—achieving lower distortion, wider bandwidth, and quieter operation.

Why It Still Matters

Analog isn’t going away—it’s evolving. These foundational op-amp circuits continue to form the backbone of countless modern designs, from audio preamps to sensor front-ends and precision measurement equipment. Pairing the timeless principles from Op-Amp Cookbook Part 2 with the performance of Linear Systems devices helps bridge the gap between theory and modern application.

So what do you think—is this “old news,” or is it still the analog engineer’s playbook?

👉 Explore our product portfolio at www.linearsystems.com and see how our devices can bring new precision to proven circuit concepts.