AION MODULAR 904A
Aion Modular expands their line of Eurorack-format Moog clones with a module inspired by the greatest filter of all time: the Moog 904A Voltage Controlled Low Pass Filter. Not to be confused with the Minimoog's lowpass filter, the 904A is the original source of a sound that has come (to many) to define the word "synthesizer": a huge-sounding 24dB lowpass with buttery resonance and a warmth unmatched by anything that has followed.
On the front panel, the 904A is simple: three selectable frequency ranges (with range 2 being the typical "audio" range), Regeneration control (resonance), Fixed Control Voltage (filter cutoff frequency), and three CV inputs. With a sound like this, though, no more bells or whistles are required—plug in a mix of waves (perhaps combined with a CP3), slowly open the filter, and listen to years of rich history gradually peek through. And Aion's 904A isn't a cheap imitation—it is as close to the original as a Eurorack module has ever come.