Coming SoonThe Mod FM is a completely self-contained 8 voice FM synth in eurorack format, which can create powerful sounds out of the box without lacking the commonly provided CV modulation possibilities.
The different sections in more detail:
4 operators are arranged in a matrix, in which every operator (= sine oscillator) can be modulated by each one of the other three.
The 16 endless potentiometers of the matrix adjust the modulation amount (FM amt) and the base frequency of the operators.
For each operator you can change the base frequency by the diagonal knobs.
There are several overtone modes that determine if one operator is controlled by the keynote (or CV) = base operator, or if it's locked in as overtone (= overtone operator) to the assigned base operator. For the base operator, the number resembles xxx semitones added to the keynote.
For the overtone operator, the adjusted number is the xxx = Nth overtone or harmonics to the base operator frequency.
The locked overtone operator tracks the base operator and is still able to modulate and being modulated.
Each operator has an ADSR envelope. This envelope can also be used to frequency-modulate the operator.
The algorithms from the known FM sythesis are actually special cases to the whole matrix.
Because it gets pretty quickly uncontrollabe if you turn all the knobs because of the feedbacks, we have decided to implement the algorithms. There are 26 algorithms, that are derived from the DX9 with its 4 operators.
At this menu it's even possible to change the frequency mode of each operator to a fixed frequency that is edited in single Hz and which does not follow the keynote, but only modulation. That makes sense for e.g. percussive sounds.
Each voice has 2 LFOs which can modulate either the frequency (FM) or the amplitude (AM) of an operator. Every LFO adresses 64 different wave forms that are displayed in the right OLED display.
There is another feature: each LFO can be switched into a VCO that covers the whole audio range. You can even mix it into the signal chain and it tracks to the keynote. The former LFO rate parameter turns into a detune parameter. That is, you can create classic sounding rectangle/sawtooth analog basses or string pads – and much more of course.
Each voice contains an analog filter which is build up with the chip SSI2140 from Sound Semiconductor, which is an improved modern version of the old SSM2040, designed by Dave Rossum, and which had been used in Oberheim synths and the early SCI Prophet-5.
The filter has a classic 24dB output and a 12dB state-variable multimode-filter. The three basic characteristic outputs LP/BP/HP can be cross-faded continuously with one parameter called shape.
Both filter outputs 24dB/12dB can be mixed independently.
The ADSR for the filter ist fast and cuts in very quick and directly, the resonance is well adjustable.
The filter section contains an own LFO for the cutoff which is independent from the digital sound engine and has also 64 waveforms.
The VCA is a fast transistor-vca which is important for snappy sounds. The same transistor-vca is used in all Jomox drum products. Therefore the ModFM can be used as a rich source for technoid drums and percussions of any kind.
On the analog voice board there is another sound source: Metal Noise. It can be mixed into the filter independently from the digital engine (= FM synth) and offers again an inexhaustable pool of weird sounds.
The Mod FM also has an FX section added: reverb and 2x delay. These only work on the stereo mix output. The delay can be beat-synchronized via midi clock and offers a very short delay time in millisecond range. That gives you flanging and oil-can-like effects.
The Mod FM is available since Septmber 2023.