Custom-made tremolos. These weren’t sampled from actual ‘tremolo’ FX units. Instead they were created from 10 different hardware chains using various pieces of solid-state hardware. The basic tremolo effect is volume level modulated by an LFO. Here, the units were sampled with one of their gain controls set to various positions. Then the LFO in Nebula is used to modulate between those positions.
Sounds simple because it is- but that’s the BASIC idea of a tremolo. These start with the basic idea, then carry it further. They are not simple gimmicks with little depth or purpose. All of these effects also include some kind of extra element, usually some kind of filtering that is modulated along with the volume level. This can enhance the tremolo in different ways. The power of ‘sampling’ with Nebula allows for the creation of custom modulation effects, similar to how an engineer would go about designing an actual hardware effect unit. The difference is that with Nebula, you can create things that would be less than practical in the hardware world.
This set has a lot of variety because of the wide range of hardware sampled, and because for each effect something else is modulated along with the volume level. Examples include: HP/LP filters sweeping inward as the tremolo goes down, 2 comb filters in a psuedo-stereo setup (from flanger pedals with their sweep LFO disabled) with increasing resonance as the level goes up, and a tilt-EQ that shifts from an upwards to a downwards slant as tremolo goes down. Further, these were all sampled with dynamics, so at any position of the modulation you get a different result depending on input level. This made the task of sampling/programming these a lot more complex (their creation is much more time consuming and involved), but it also keeps them more ‘analog-sounding’.