Happy Nerding FM Aid, a 4HP Eurorack module with which you can generate wild through-zero linear FM timbres from any signal
Frequency modulation is a synthesis method that you wouldn’t want to miss in the Eurorack system. Often, simple oscillators in particular are very simple and FM doesn’t sound perfect either. However, there is a tool that significantly enhances every oscillator. FM AID from Happy Nerding is a phase modulation-based module that creates through-zero linear frequency modulation with any signal.
The result is that the module copies FM in how it is done in digital implementation, but in a completely analog circuit free of digital aliasing artifacts. More precisely, they use a ramp waveform to form other shapes. Powerful for sound design is that you can use any signal as a carrier & modulator, not just classic waveforms. This creates complex waveforms on the output quickly.
Happy Nerding FM Aid
FM Aid offers also all other digital-related FM tricks: you can endlessly experiment with the carrier/modulator frequency ratios, modulation index (FM knob), modulator’s amplitude shaping (CV knob), feedback FM, and many other.
The carrier input is normalled to the modulator’s input but you can break this routing by inserting a plug in the mod input. That is a clever option that allows you to use the module with only one signal source where it acts as a carrier and modulator at the same time. It won’t produce any frequency between both but creates versatile wave folding sounds.
Happy Nerding FM AID has been on the market for a long time. However, Igor from Happy Nerding has just released a revised version with a slimmer 4HP footprint.
It is a module that should find a place in every Eurorack case. It is very easy to use, takes up little space, and in no time you have wild, useful FM sounds that are often only possible with complex oscillators. At € 135/$150 USD, it’s also very affordable. The module is also available in a Dotcom/Moog Modular version for $200 USD.
More information here: Happy Nerding