The Hexeract CMOS Drive is an overdrive pedal that utilizes cascaded CMOS inverters to create a unique and warm tone. This technique, pioneered by Craig Anderton in his “Tube Sound Fuzz” DIY project, offers a different sound compared to traditional clipping diodes.

The original inspiration for the Hexeract CMOS Drive comes from the Electro-Harmonix Hot Tubes, a CMOS-based overdrive pedal released in 1978. The Hot Tubes was one of the first commercial products to utilize overdriven hex inverters, which produce a softer and more asymmetric clipping compared to diode-based circuits. This characteristic gives the Hot Tubes a vintage tube amplifier-like sound.

The Hot Tubes featured additional op-amp stages and a tone control, making it a versatile and full-featured overdrive pedal. It gained popularity during its production period from 1978 to 1981, despite the financial troubles that led to its discontinuation.

In 2005, Electro-Harmonix released another pedal called the Hot Tubes, but this time it was a true tube overdrive pedal. This caused confusion among enthusiasts, as the 2005 version had no relation to the original CMOS-based Hot Tubes. However, in 2013, Electro-Harmonix reissued the original CMOS circuit as part of their Nano series and later combined it with the Crayon to create the “Hot Wax” dual pedal.

The Hexeract CMOS Drive is a faithful reproduction of the original 1978 Hot Tubes circuit. Some minor additional filtering has been implemented, but the overall design remains true to the vintage sound.

Summary created by AI from the original source.