DOEPFER System A-100 Synthesizer Voice A-111-5 1. Introduction Fig.
Synthesizer Voice A-111-5 System A-100 Module A-111-5 is a complete monophonic synthesizer module that includes these components: VCO • manual tune control (with an internal jumper the range can be set to ~ +/-1 half an octave or ~ +/-2.5 octaves) • range switch -1 / 0 / +1 octave • frequency range about 10Hz ...
DOEPFER System A-100 VCA ADSR • manual amplitude control • AM (amplitude modulation) control with modulation source switch (LFO1 / off / ADSR) • external CV input for VCA amplitude • special control scale: exponential scale in the range from about -20dB to -80/90dB, linear scale from about -20dB to 0dB Remark: this special control scale results in a loudness behaviour that is a bit different from pure linear or exponential VCAs • • • • Synthesizer Voice A-111-5 manual controls for Attack, Decay, Sust
Synthesizer Voice A-111-5 System A-100 Remarks: • As the LFO frequencies can go up to moderate audio range (~ 5kHz) even audio FM effects of VCO (pitch and pulsewidth), VCF and ADSR are possible ! • If the VCO is turned off (waveform switch = center position, pulsewidth control = fully CCW) and the VCF resonance is set to maximum the module can be used as a sine oscillator.
DOEPFER System A-100 Synthesizer Voice A-111-5 2. Overview Fig.
Synthesizer Voice A-111-5 7 1 8 2 9b 3b 9a 3a 5 10 4 6b 6a 6 DOEPFER System A-100 11 Fig.
DOEPFER System A-100 Synthesizer Voice A-111-5 Fig.
Synthesizer Voice A-111-5 1 2 3 4 Fig.
DOEPFER System A-100 3. In- / Outputs 1 VCO Frequency Control Input (1V/Octave) This input is used to control VCO frequency from the socket at the front panel. It works in addition to the control voltage that is applied to the CV line of the A-100 bus – provided that the corresponding jumper JP2 is set (details in the appendix) – and the internal frequency settings and modulations (controls 1, 2, 3a and 3b). Both CV inputs can be used simultaneously (e.g.
Synthesizer Voice A-111-5 System A-100 DOEPFER controls 12 and 13b are fully CCW). To reduce the sensitivity of this CV input an external attenuator module has to be used (e.g. A-183-1). a different signal appears at this socket (details in the appendix). They can be used to control other A-100 modules. 5 8 ADSR Gate Input This input is used to trigger the envelope generator (ADSR). A trigger voltage between +5V and +12V is required to trigger the envelope.
DOEPFER System A-100 4. Controls 1 2 3a 3b VCO Tune VCO Range Switch (Octave Switch) VCO FM Source Switch VCO FM Level This group of elements is responsible for the frequency of the Voltage Controlled Oscillator (VCO). Tune control 1 enables the tuning of the oscillator frequency in a range of roughly one octave (or ± ½ octave). By means of an internal jumper (JP4) the range can be extended to roughly six octaves. For details please refer to the appendix. The factory setting is one octave.
Synthesizer Voice A-111-5 System A-100 5 VCO Rectangle Pulsewidth 6a VCO Pulsewidth Modulation Source 6b VCO Pulsewidth Modulation Level This group of elements is responsible for the additional rectangle wave ("second" waveform) that can be added to the waveform chosen by switch 4 . Control 5 is used adjust the pulsewidth of the rectangle manually. In the center position the pulsewidth is about 50% (provided that no Pulsewidth Modulation is active).
DOEPFER 7 8 9a 9b 10 System A-100 VCF Frequency VCF Tracking Switch VCF exponential FM Source Switch VCF exponential FM Level VCF linear FM Level This group of elements is responsible for the frequency of the Voltage Controlled Filter (VCF). A 24dB Low Pass Filter with adjustable resonance is used in the module. In addition the filter features linear frequency modulation. A detailed description of different filter types can be found in the user manuals of the A-100 filter modules (e.g. A-120 or A-121).
Synthesizer Voice A-111-5 System A-100 In addition to the internally generated frequency of the filter the control voltage applied to the "VCF F" socket 3 modulates the frequency of the VCF as described in chapter 3. The LM control 10 is very unusual for a filter. The position of this control defines the intensity of the internal linear frequency modulation of the VCF by the triangle of the VCO.
DOEPFER 12 13a 13b System A-100 VCA Amplitude (Manual Gain) VCA AM Source Switch VCA AM Level This group of elements is responsible for the amplitude or loudness of the Voltage Controlled Amplifier (VCA). Amplitude control 12 is used to adjust the loudness of the VCA from zero to maximum manually. In other synthesizers this control is sometimes called "initial gain". If the VCA is controlled by the ADSR this control is usually set to zero.
Synthesizer Voice A-111-5 System A-100 14a LFO1 Frequency 14b LFO1 Frequency Range Switch 14c LFO1 Waveform Switch This group of elements is responsible for the adjustment of Low Frequency Oscillator 1 (LFO1). Switch 13a is used to select the frequency range: upper position: center position: lower position: low ~ 0.005Hz/200s ... 2.5Hz/400ms high ~ 20Hz ... 10kHz medium ~ 0.1Hz/10s ... 50Hz/20ms The lower position is the standard LFO setting.
DOEPFER 16 17 18 19 20 System A-100 ADSR Range Switch ADSR Attack Time ADSR Decay Time ADSR Sustain Level ADSR Release Time This group of elements is responsible for the adjustment of envelope generator (ADSR). Synthesizer Voice A-111-5 The low range is intended for very long envelopes up to several minutes. As the time ranges overlap certain envelope times can be generated in two ways (e.g. 50ms is covered by high and medium range).
Synthesizer Voice A-111-5 6.
DOEPFER System A-100 The basic position of the controls shown on the previous page is a good starting point as it generates a well-known standard synthesizer sound. The VCO uses a combination of sawtooth and rectangle with a slow pulsewidth modulation to obtain a fatter sound. The frequency modulation of the VCO if off. The VCF has a light resonance and is modulated by the ADSR. The linear modulation of the VCF (LM) is off. The VCF tracking is on (i.e. the VCF frequency follows the VCO frequency).
Synthesizer Voice A-111-5 DOEPFER System A-100 Appendix: Position and function of the jumpers (JPx) and trimming potentiometers (Px) A-100 Bus 20
DOEPFER System A-100 Synthesizer Voice A-111-5 Jumper Overview Name JP1 JP2 Function A-100 Bus CV Bus JP3 Gate bus JP4 VCO tune range JP5 Audio Æ Bus/+5V JP6 Relation VCO/ext.
Synthesizer Voice A-111-5 DOEPFER System A-100 Trimming Potentiometers Overview Name P17 Function VCO Scale P18 VCO Offset P19 VCO Octave Switch + P20 VCO Octave Switch - P21 VCF Scale P22 VCF Offset R23 Minimum VCA level Explanation adjusts the 1V/octave characteristics of the socket "VCO F" or the bus CV adjusts the VCO frequency offset adjusts the upper position of the VCO range switch (+ 1 octave) adjusts the lower position of the VCO range switch (- 1 octave) adjusts the 1V/octave cha
