Synthesis Technology E440 Discrete OTA Eurorack VCF Module

The E440 is based on the 5U MOTM-440 filter with additional features such as separate outputs for each filter slope and an input Drive control.

You have probably heard of the SSM2040 filter chip, used in the Prophet-5 Rev 2, Voyetra 8, and others. Although short-lived, the SSM2040 filter had a unique sound different from a Moog, ARP, or other 4-pole lowpass filters. Why? The design used a clever discrete OTA gain cell that responds beautifully as additional gain is added to the input signal.

The E440 provides three simultaneous filter slopes: 2 Pole (12dB), 3 Pole (18dB), and 4 Pole (24dB) for selective timbral shaping. Voltage control of filter resonance (rarely found on other filters) is also available.

Height 3U (128.5mm)

Width 14hp (70.8mm)

Depth 32mm

Power 14-pin Eurorack (23mA from +12V, 12mA from -12V)

CV input range 10Vpp (-5V to +5V), DC to 10KHz

(Res CV range is 0V-5V)

Audio Input 50K nominal input impedance, 100mv to 14Vpp

Audio Output 14Vpp (-7V to +7V), 20Hz to 18KHz frequency range

Jumper Options JP1: Bass boost enhancement (OFF/ON)

Resonance Sets the initial filter resonance

Frequency Sets the initial filter frequency

FM 1 / FM 2 Attenuator for the FM CV inputs

Drive Increases the gain of the input signal

1V/Oct 1 volt per octave control for the initial filter frequency

FM 1 / FM 2 Filter frequency modulation inputs

Res CV Resonance modulation input

Audio In Signal input for the filter

2/3/4 Pole Out Audio outputs for various filter slopes (12dB/18dB/24dB)