Terminal Dual Complex Function Gen / Dual VCFA / Echo FX - 26HP

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Item: N13-3579

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Terminal Dual Complex Function Gen / Dual VCFA / Echo FX - 26HP


Take flight with the Endorphin.es Terminal! This unique and complex module includes dual voltage controlled looping envelope generators, dual low-pass gates, and a stereo output section with echo fx. The perfect match for their popular Furthrrrr Generator, and an extremely powerful module by itself!

The Terminal in a nutshell:

  • Dual Low Pass Gate, which functions somewhere in between a VCA and a VCF.
  • Dual Envelope Follower, for creating control voltage from the volume of another audio signal.
  • Dual Looping Attack-Sustain-Release function generator with CV controllable slope and time, for use as waveshapable envelopes, LFO's, and even VCO's in high range.  
  • A Voltage Controllable Digital Reverb, for adding the perfect amount of space, or ambience, to your audio mix.
  • A Stereo Mixer with panning capabilites.


The envelope generators are in a class of their own and can be used as voltage controlled envelopes, LFOs, and even Oscillators, with its unique precision design. These "Airplanes" are transient function generators that generate control voltages after an upcoming trigger/pulse. They each have two phases, Take Off (Rise, or Attack), and Landing (Fall, or Decay) with both unipolar (0V to +8V) as well as bi-polar (-5V to +5V) outputs or "exits" for each envelope. Trigger outputs are sent at the end of each stage, (end of Rise, end of Fall), of the envelope. Three modes are available for each generator:

  • Cruise Mode allows the envelope to function with sustain as long as the gate signal is present in the input of an "Airplane." Once the gate signal is removed, the fall function is initiated. 
  • Transient Mode gives a standard envelope with no sustain. As soon as the Rise function has completed, the Fall function is immediately initiated. 
  • Looping Mode retriggers the envelope as soon as its single cycle is over, which allows the envelope to be constantly oscillating. In this setting, the terminal can be used as either an LFO or an oscillator depending on the frequency of the cycling. 

The duration of Take Off, (rise), and Landing, (fall), stages are separately voltage controlled and can be controlled manually with the according knob or via incoming control voltage (the amount of CV is defined by using the knob as an attenuverter). When nothing is plugged into CV and key inputs, Take Off and Landing knobs vary the duration time of corresponding stage from 1 millisecond to 10 seconds. When no control voltage plug is inserted into appropriate CV IN jack, each attenuverting knob defines bending of according curve of the certain slope: either to exponential shape (knob is in far counterclockwise position), either to linear (knob is in centered position), either to logarithmic (knob position is far clockwise). Adjusting the linearity doesn’t change the duration time of the according stage, as it’s usually expected in analog envelope generators. 

The Peak Detector continuously tracks the heights of both Airplanes and outputs the CV of one which is higher at the moment. There is an attenuating knob ‘relative B height’ for decreasing the height of Airplane B related to the Airplane A. Triggering both envelopes at same time – when Airplane A is in transient and Airplane B in cruise mode– allows to obtain an approximate ADSR-like envelope output.

In looping mode, both Airplanes work as Voltage Controlled Oscillators with separately controlled take off and Landing slope rates as well as separately controlled shapes of each slope. With the take off and landing knob in the far counterclockwise position, with no additional voltage applied, each stage has a duration of 1 ms or 500 Hz per whole cycle. The key In jack handles one volt per octave exponential input to control/modulate the VCO under incoming voltage. The acceptable control voltage range is positive only, from zero up to 6.6 volts– i.e., aproximately six and a half octaves above the current pitch of the cycled envelopes but not higher than 15 kHz.

The Gates or Gateways are opto-coupler-controlled Sallen-Key low-pass filter amplifiers. That means altering the gates offsets will alter both frequency cutoff and amplitude of the signal giving natural musical response, similar to acoustic instruments. Each gate has attenuverting CV inputs and gate A has an attenuverting audio input. In the middle position of the attenuverting knob no signal will pass into the according input. Cranking the knob clockwise will increase the passing of the original signal and turning the knob counterclockwise results in passing the inverted signal. By default each gate alters the cutoff frequency and amplitude that suits best for bongo and other 'pinging' timbres. There is one extra Voltage Controlled Filter mode thatenables full 12db/oct filtering without altering the amplitude of the signal. 

Afterwards, both gates sum together to the final output section. There is also a separate output of gate A. Inserting a plug to it will disconnect gate A from the mixer (and no summing happens) so you may feed the output of gate A into other modules or directly into the audio input of Gate B to obtain a steeper cutoff slope. The inputs of each gate are DC-coupled and may be normalled to each other. That means a signal plugged into one Gate may be plugged simultaneously into another one as well. That connection breaks when any other plug (even an unconnected one) is inserted into another Gate's audio input. Passing the same signals to both gates and playing with the input phase and amplitude of gate A using the attenuverter (so the offsets of each gate will result in mixing of a low-passed signal with the pure inverted signal), will cause a high-pass effect.

There is no dedicated control of resonance (emphasis) at the gates but it may be achieved with an additional mixer module or by patching the mono final output (marked with a loudspeaker) into the input of a gate, i.e., organizing the feedback loop of the signal. It is convenient to send feedback into gate A where additional control over input phase and volume is given by the attenuverting knob.

The Final Output section has separate stereo and mono outputs, which share the same volume knob. At full gain (knob fully clockwise) and center Panning knob the audio signal at the mono output is literally at a standard modular level (roundabout ±5V or 10Vpp). The Mono output is DC-coupled and has 1kOhm output impedance, as ordinary modular audio outputs are. It is possible to plug headphones or stereo amplifier system directly into stereo output, marked with the headphone icon. The stereo output is AC-coupled (to prevent possible damage of your audio system by DC signals) and has got a pretty good level of output current to drive a wide range of headphones. The output amplitude of the stereo out is lower than the ordinary modular level and is close to ordinary line level. Please connect only stereo headset/amplifiers to the stereo output.

The Cabin pressure is a 12-bit 26-kHz sample rate digital effect that recreates some sort of reverb/echo with a few reflections (taps), the rate of which is controlled with a clock. The main intention of it is to add some air to the final audio output mostly at live performances. Tap tempo allows to create rhythmic delay effects that are also syncronized to the rest of the instruments used. It accepts low frequency trigger signals higher than 0.65 volts, namely BPM clock of the track. When the incoming clock signal is faster, it resembles some sort of chorus effect, and at rates faster than 50-60 Hz, the taps become almost mute in echo tails but may berecognized as a short clicks at attack sounds only. It’s possible to remove the plug from the tap clock input jack because it will remain the same speed once it was synconized. Three sequential taps (triggers) are enough to adjust the echo to a new tempo. At the modules' power-up the maximum tempo available until a new clock is received by the clock input.


  • 26 HP width, up to 1" in depth (super slim & therefore skiff friendly).
  • Dual voltage controlled AD/AR/looping envelope generators with arbitary voltage controlled slope shapes: from EXP to LIN to LOG without stretching the time length of a certain slope.
  • 1 volt per octave control over envelopes in the looping mode (to use the envelopes as band-limited oscillators).
  • Dual opto-coupler controlled gates with universal sockets for a quick and simple exchange: one can use the factory supplied opto-couplers, replace the m with other ones or even roll your own: slow, fast, ringing – whatever!
  • Voltage controlled cabin pressure effect. Add space to the final mix with the proper CVand TAP controls.
  • Don't forget the stereo – dedicated stereo headphone output with voltage controlled panning.

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  • 26 HP/TE width, up to 1" in depth (skiff friendly)
  • +12V - 185mA max
  • -12V - 115mA max
  • 300 mA total
  • No +5V required. 

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