Synthesis Technology - E440 Discrete OTA VCF

The Synthesis Technology - E440 Discrete OTA VCF sounds great, realised with the highest-quality pots and knobs, it is pleasing all over the place! Connect any audio source and you will be pleased at any setting. You may wonder why? Simply because of the architecture of the filter circuitry that provides equal amounts of gain. One of our all-time favourite filters.

Synthesis Technology - E440 Discrete OTA VCF - overview

Synthesis Technology MOTM E-440 is an analog discrete low pass filter with three simultaneous filter types (-12dB, -18dB and -24dB). It also offers voltage control of resonance and overdrive.

technical details

The E-440´s audio input has a drive control that one one hand is a signal attenuator but on the oter hand it can also amplify signals with the factor 2. You can amplify line level signals and distort the filter´s input. Unity gain is approximately at the "4"-position. A jumper on the modules back activates the bass boost enhancement.

The E-440 has three filter outputs with slopes of -12dB, -18dB and -24dB/octave, each of them is phase shifted 45° from the prior one. Mixing the filter outputs will generate different slopes, mixing with inversion will result in different frequency response.

For controlling the cutoff frequency there are three CV inputs, the first one working with a characteristic of 1V/octave and tracks over 4 octaves (trimmabla nad temperature compensated), CV input FM1 has an attenuator, FM2 has a polarizer. The resonance can be voltage controlled as well and the filter can self oscillate at potentiometer position 9. The voltage generated by the resonance pot will be mixed to the external CV.

CV Inputs: -5V to +5V, DC to 10KHz. RES IN is 0V (no resonance)to +5V (full resonance).

Audio input: 50K nominal input impedance, 100mv to 14V pk-pk.

Outputs: -7V to +7V, 20Hz to 18KHz

inputs and outputs

One audio input, separate outputs for the 2-pole, 3-pole and 4-pole low pass filter.

3 CV inputs for controlling the cutoff frequency. 1x 1V/octave and two controlable FM inputs. One resonance CV input.

measures and weight

3U Eurorack module, 14HP wide. Current draw each 23mA per +12V and -12V rail.