XAOC Devices Odessa

For my portable rig case this is quite a big module. On the other hand it's the only oscillator module I carry around cos it's SO deep. Especially since I got the HEL expander for Odessa, which basically turn it into a (technically not) polyphonic osc.
The build quality is fantastic, as with all XAOC modules.

Things to be aware of before buying:

1-The sweet spots are quite narrow, but they're the sweetest.

2-Keep in mind this is an oscillator, not a synth module which means:

3-You'll need loads of modulation to make the best of it. Even though Odessa has attenuators (that's what the sliders are for) you'll need way more of them to achieve more melodic and less experimental results.

4-If you buy the Hel expander, which I recommend, you'll need a quantizer to make the most of those inputs and play melodies.

5-You'll need a VCA, since like all oscillators, Odessa outputs constant audio at modular level.

If you already have all of this, you're ready for some deep, spacey, glassy, warmest FM trip!

If you're reading reviews you probably already saw the amazing demos of Odessa. There's just something special about its sound! The build quality is superb, one of the best if not the best of my 12U rack.

The only downside is, sometimes it might take a little effort to produce the sound you want. Some of the parameters are quite sensitive and tiniest changes have a drastic effect on the resulting sound, and sometimes the timbre changes in a non-trivial way when you move up or down an octave. But in practice this just leads to a lot of happy accidents.
I'd recommend the "twist all the knobs and look for sounds" technique in the beginning and letting Odessa take you where it wants to go.

Once you start adding FM the whole thing becomes a beast! It's insane the range of crazy sounds you can get.

If you like the sound demos, you should absolutely buy it, I promise you won't regret it.

This is really a beautiful module with an incredible amount of control. Essentially you manipulate the occurrence and amplitude of different harmonics in a very playable way. They can all be externally modulated.

Some ideas if you're wondering what it can do: One of my favourite features is that the odd and even harmonics have separate outputs and this is really a genius move. By putting them out in stereo and modulating the Bank length the effect is a kind of sparkle that pans from left to right underneath the main tone.
It's fun to use the FM inputs with audible frequencies but also the Exp FM slider is just about smooth enough that, with a square LFO to modulate it, you can dial in a specific interval (with a bit of trial and error) and have your sequence move in a really melodic way.

Waiting for the Hel module to arrive so can't comment on how well they play together.