The “XL741” Discrete Operational Amplifier kit from Evil Mad Scientist Laboratories is a faithful and functional transistor-scale replica of the μA741 op-amp integrated circuit, the classic and ubiquitous analog workhorse.

Operational Amplifiers (a.k.a.: “op-amps”) are one of the most useful & common analog electronic circuit building blocks. The original μA741 was designed by Dave Fullagar and released by Fairchild in 1968. It quickly became the quintessential and most popular op-amp of all time. While newer op-amp designs may outperform the μA741 in just about every possible respect (speed, noise, voltage range, and so on), the 741 remains widely beloved and in active production today — over 45 years later.

The XL741 kit was designed by Eric Schlaepfer, in collaboration with Evil Mad Scientist Laboratories. The kit is lovingly designed to resemble an (overgrown) integrated circuit, based around an extra-thick matte-finish printed circuit board. It comes complete with a beautiful aluminum display stand that gives the circuit board eight legs in the shape of DIP-packaged integrated circuit pins.

The XL741 kit is sold as an easy-to-build soldering kit, including the circuit board, resistors, transistors and capacitor and printed assembly instructions.

To build the XL741 kit, basic electronic soldering skill and tools are required, but no additional knowledge of electronics is presumed or required. You provide standard soldering tools: a soldering iron + solder and small (“flush”) wire clippers, as well as a Phillips head screwdriver. The kit features easy “through-hole” construction (“No surface-mount nothin’ nowhere!”), and (assuming that you have prior soldering experience) should take roughly an hour to build.

Specifications

• The XL741 kit printed circuit board is 5.215 × 3.175 inches (13.25 × 8.06 cm) in area, and (nominally) 0.100″ (2.54 mm) thick.
• Including the “Integrated Circuit Legs” stand and terminal posts, the overall size of the assembled kit is nominally 5.215 × 3.9 × 1.70 inches (13.25 × 9.9 × 4.3 cm).
• The circuit board accommodates eight 8-32 threaded inserts for the color-coded terminal posts (included)

Evil Mad Scientist is a trademark of Bantam Tools, used under license.