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Notes: Module A-115 is a four-way frequency divider. The frequency of a signal at the input is halved (half frequency = first sub-octave), quartered (1/4 frequency = second sub-octave), and so on. In this way, the DIVIDER produces four sub-octaves (F/2 down to F/16).

At the output, the A-115 produces a summed mix of the original and the four sub-octaves. There are attenuators to control the amount (i.e. Amplitude) of the original signal and each of the sub-octaves.

Bear in mind that the sub-octaves output by the A-115 are all true square waves. At the output there are always four square waves and the original signal available.

Notes: Module A-143-9 is a derivative of our planned thru-zero quadrature VCO. It is a voltage controlled sine LFO with 4 outputs. The phase shift between the outputs is 90 degrees. The sine shifted by 90 degrees is also called cosine, the sine shifted by 180 degrees is nothing but the inverted sine, and the sine by 90 degrees is nothing but the inverted cosine.

The frequency range is from some minutes to frequencies beyond audio with three ranges selected by a toggle switch:

- Switch position H: about 30 Hz ... 3.5 kHz with the manual frequency control ("Frq."), beyond 20 kHz with additional external CV
- Switch position M: about 1 Hz ... 150 Hz with the manual frequency control ("Frq.")
- Switch position L: about 0,1 Hz ... 10 Hz with the manual frequency control ("Frq."), down to several minutes with additional external CV

Two exponential frequency control inputs are available: CV1 without attenuator and CV2 with polarizer. Consequently the module can be used even as an experimental sine VCO but does not feature an exact 1V/oct CV input! The precision CV input will be left to the thru-zero quadrature VCO.

Two LEDs display the positive and negative share of the sine output.

The core of the module is a so-called quadrature circuit that generates a sine a cosine signal with very low distortion. The quality of the sine/cosine signals are much better than those generated by a waveform converter with a sawtooth or triangle signal as starting point.

The output levels are about 5 Vss (+/-2.5V) but can be adjusted internally by a trimming potentiometer (P5 "Shape").

Typical applications:

- External sine/cosine oscillator for the frequency shifter A-126
- Modulations with pure sine/cosine waveforms
- Quadrature/barberpole effects (e.g. with the voltage controlled mixer A-135)
- Experimental sine/cosine VCO (e.g. for FM sounds)

Many users suggested to add a common output level control, i.e. four VCAs with one common control (manual + CV without attenuator + CV with polarizer) for the output levels. This is why we also designed the Quad VCA module A-132-2 with the possibility of an internal default connection to the four outputs of the A-143-9 (no soldering required, short 10 pin flat cable with removable connectors on both ends).

The A-143-9 is also a meaningful addition for the Frequency Shifter module A-126. It enables frequency shifting even below 50 Hz generating e.g. these mellow beat sounds with a few Hz frequency shifting only. The following document describes how to connect the A-126 and the A-143-9: A126_A143_connection.pdf.

The thru zero version of the A-143-9 with temperature compensation is the module A-110-4.

Notes: Module A-182-1 is a simple passive multi-connector similar to the multiples modules A-180-1/A-180-2. In contrast to modules A-180-1/2 each socket is equipped with a 3-position switch that allows to connect the corresponding socket to the internal bus #1 (left position), bus #2 (right position) or to turn the socket off (centre position).

Examples:

- All switches in left position or all switches in right position: 8-fold multiple

- Four switches in left position and four switches in right position: two 4-fold multiple

- X switches in left position, Y switches in right position and Z switches in centre position: two separate multiples with some sockets turned off

Notes: Module A-184-2 is the combination of two functions and planned primarily as an expansion module for VCOs or LFOs (e.g. A-110-1, A-110-2, A-145, A-147-2).

Triangle-to-Sine Waveshaper:

The upper section is a very precise triangle-to-sine converter (thanks to Tim Stinchcombe who recommended this circuit). It can be used to convert any triangle waveform into a (nearly) perfect sine. The converter is much better than the simple diode converter used in the A-110-1, A-111-1, A-145 and A-147-2. Two trimming potentiometers are used to optimize the sine shape. The converter should be assigned to one VCO or LFO because the trimming potentiometers have to be re-adjusted if the input level or DC offset of the input signal changes. If the trimming potentiometers are deliberately mis-adjusted it can be used also as a waveshaper for non-sine waveforms (e.g. sine-shaped at the top of the signal and a peak at the bottom, even voltage controlled by applying an additional voltage to the waveshaping circuit, "circuit-bending" notes will be available).

The waveform converter is DC coupled and can be used also for low frequencies (e.g. LFO triangle waves).

Voltage Controlled Crossfader:

The lower section is a voltage controlled crossfader. It has two inputs A and B. The two signals are mixed together with variable percentage. When the manual control CF is fully CCW only signal A appears at the CF Out socket. When the manual control CF is fully CW only signal B appears at the CF Out socket. In the centre position of the manual control both signal appear with the same level. In addition a control voltage input CV with attenuator is available to enable voltage control of the crossfade.

Two LEDs display the crossfading shares of input A and B.

The crossfader uses two high quality VCAs (SSM2164). Inputs and outputs are DC coupled. Consequently it can be used for audio signals and slowly varying control voltages as well.

The sockets of the upper section (triangle and sine) are normalled to the inputs A and B of the crossfader section. That way the crossfader is used to fade between triangle and sine of the VCO or LFO connected to the waveshaper. If other signals are plugged into the input sockets A and B these signals are used for crossfading.

The main application is to fade between two different waveforms of a VCO or LFO or two different VCF outputs. But the module can be used for any other signals too as the waveshaper and crossfader sections are independent apart from the normalled sockets.

Notes: Blank panel, 1HP, constructed from anodised aluminium, silver.

Notes: Blank panel, 1.5 HP, constructed from anodised aluminium, silver.

Notes: Blank panel, 4HP, constructed from anodised aluminium, silver.

Notes: Blank panel, 8HP, constructed from anodised aluminium, silver.

Notes: Blank panel, 42HP, constructed from anodised aluminium, silver.

Notes: A-100SSB is a combination of power supply and bus board with 8 connectors for A-100 modules, planned for applications with up to 8 modules and a max. current of 380 mA.

- Wide range mains voltage input 100-240V AC / 50-60 Hz
- IEC inlet on board for the connection of a suitable mains cable (a suitable mains cable has to be purchased by the customer locally, it's not included with the A-100SSB)
- Switching supply with +12V/380 mA and -12V/380mA for the operation of A-100 modules up to 380 mA total supply current
- Safety cover at the bottom side (covers all elements that lead mains voltage)
- On board fuse
- 8 bus connectors
- LED displays for +12V, -12V and +5V
- Dimensions: about 270 mm (length) x 55 mm (width) x 35 mm (height)
- Several 3mm holes for mounting the unit on a rear panel or bottom plate

Notes: - High-grade patch cable designed for modular units
- 3.5mm mono jack plugs
- Length: 50cm
- Transparent cabling

Notes: - High-grade patch cable designed for modular units
- 3.5mm mono jack plugs
- Length: 80cm
- Red finish

Notes: - 6.3 mm jack male mono to 3.5 mm jack male mono
- Length: 3 metres

Notes: High quality rotary knob, for use with Doepfer or a wide range of modules. Robust design with indented edges. Grey finish.

Notes: High quality rotary knob, for use with Doepfer or a wide range of modules. Robust design with indented edges. Retro style finish.

Notes: Module A-145-4 is a simple quad LFO (Low Frequency Oscillator). Not a very "exciting" module, just a bread-and-butter device and a simple demon for work. Virtually in every modular system several LFOs are required for modulation purposes. The module contains four simple LFOs with the waveforms triangle and rectangle. A dual colour LED (red = positive / yellow = negative output voltage) indicates the triangle output of each LFO. The frequency range can be chosen for each LFO individually by means of a jumper between about 50 Hz ... 0.04 Hz (about 20 seconds, jumper removed) and about 2Hz ... 0.002 (about 8 minutes, jumper installed).

The module can be treated as a slimmed version of the quad LFO A-143-3 as it has similar features available. But the distances between the controls are smaller and rubberized small-sized knobs are used. In return the front panel has 4 HP only which is less than one third of the A-143-3. The module is primarily planned for applications where only limited space is available. The functional difference compared to the A-143-3 are the missing sawtooth outputs and frequency range switches.

Notes: Patch cable for modular synthesizer 80 cm, transparent, mono jack plug 3.5 mm at each end.

Notes: Blank panel, 4HP, constructed from anodised aluminium, black.

Notes: Blank panel, 8HP, constructed from anodised aluminium, black.

Notes: Module A-130-2 is the slim version of module A-132-3 and offers essentially the same features. But the distances between the controls are smaller and rubberized small-sized knobs are used. In return the front panel has 4 HP only which is half the width of the A-132-3. The module is primarily planned for applications where only limited space is available.

The module is composed of two identical voltage controlled amplifiers (VCA). Each VCA has a manual gain control (also named Initial Gain) and a control voltage input with attenuator. The character of the control scale can be switched to linear or exponential. All inputs and outputs are DC coupled. Consequently the VCAs can be used to process both audio and control voltages (e.g. for voltage control of the level of LFO or envelope signals). The signal input has no attenuator available but is capable to process up to 16Vpp signals (i.e. -8V...+8V) without distortion. For the processing of higher levels an external attenuator (e.g. A-183-1) is recommended.

The amplification range is 0...1. Even with a higher external control voltage the amplification remains at 1 (kind of "amplification clipping" at 1).

Controls (for each of both units):

- Gain: manual gain control (Initial Gain) in the range 0...1
- CV: attenuator for the CV input
- Lin/Exp: switches the VCA characteristic to linear or exponential, in center position the VCA is off (mute function)

Inputs and outputs (for each of both units):

- CV: control voltage input, min. +5V required for max. amplification (1) with CV control fully CW and Gain fully CCW
- In: signal input, max. 16Vpp (+8V...-8V) without distortion
- Out: signal output

Notes: Module A-145-4 is a simple quad LFO (Low Frequency Oscillator). Not a very "exciting" module, just a bread-and-butter device and a simple demon for work. Virtually in every modular system several LFOs are required for modulation purposes. The module contains four simple LFOs with the waveforms triangle and rectangle. A dual colour LED (red = positive / yellow = negative output voltage) indicates the triangle output of each LFO. The frequency range can be chosen for each LFO individually by means of a jumper between about 50 Hz ... 0.04 Hz (about 20 seconds, jumper removed) and about 2Hz ... 0.002 (about 8 minutes, jumper installed).

The module can be treated as a slimmed version of the quad LFO A-143-3 as it has similar features available. But the distances between the controls are smaller and rubberized small-sized knobs are used. In return the front panel has 4 HP only which is less than one third of the A-143-3. The module is primarily planned for applications where only limited space is available. The functional difference compared to the A-143-3 are the missing sawtooth outputs and frequency range switches.

Notes: A-182-2 is a simple passive module that contains four changeover switches, which are used to connect or disconnect the sockets of the corresponding socket triplet:

- In the upper position of the switch the upper socket of the corresponding socket triplet is connected to the centre socket
- In the lower position of the switch the lower socket of the corresponding socket triplet is connected to the centre socket
- In the centre position of the switch the sockets are not connected

Each unit of the module can be used to switch between two signals or to interrupt/connect a signal. In the last case the third socket of the triplet is not used.

The module is fully passive and both audio or control signals can be switched.

Notes: Module A-183-9 is a simple power supply for up to four devices which can be powered via USB (e.g. keyboards, smartphones). An LED shows is the +5V are present.

The module has no USB function but provides only the +5V supply for USB devices.

A control LED shows if the +5V are present.

Note: The module requires an A-100 case with built in power supply A-100PSU3. Only this A-100 supply has the required +5V available. We do not recommend the usage of an older A-100 case with A-100PSU2 as this would require the +5V adapter A-100AD5 and the max. current would be limited to 100mA.

Notes: Module A-124 is a special 12dB multimode filter using the "strange" filter circuit of the "EDP Wasp" (an analog synthesizer with black/yellow case built end of the seventies, manufactured by the UK company "Electronic Dream Plant" with Chris Huggett und Adrian Wagner). This design "abuses" digital inverters as analog operational amplifiers leading to distortions and other "dirty" effects that generate the specific sound of this filter. The filter is equipped with a band pass output and a combined low/notch/high pass output. For this output a control knob defines the relation between low and high pass signal. If both signals appear at the same level (i.e. middle position of the Mix knob) one obtains a notch filter. Otherwise the low or high pass signal predominates. The module does not feature self-oscillation in contrast to most of the other filters of the A-100 system.

Inputs: Audio In, CV In (2x)
Outputs: Bandpass Out, Low/Highpass Mix-Out
Controls: Audio and CV attenuator, Frequency, Resonance, LP/HP Mix

The function and operation of this module is very similar to the module SEM VCF A-106-5. But the sound of both filters is very different! The only functional difference is the position of the sockets and controls, and the function of the controls CV2 (A-124: normal attenuator, A-106-5: polarizer).

- 3U Eurorack module, 8HP wide, 45mm deep
- Current draw 30mA

Notes: A-138s is a simple but useful 4-in-2 mixing tool. It has four inputs available. Each input is equipped with an attenuator (Level) and a panning control that is used to distribute the signal to the left and right output. Beyond stereo mixing it is equally suited to create variable parallel routings. For example: Any of the four inputs may be routed in variable intensity to feed two filters.

You may regard the A-138s as a smaller version of the A-138m Matrix Mixer.

Inputs and outputs are DC coupled, i.e. the module can be used for the mixing of control signals too.

- 3U Eurorack module, 8 HP wide, 30 mm in depth
- Power consumption: 10 mA at +12 V and 10 mA at -12 V

Notes: Module A-112 is the combination of a voltage controlled 8 Bit Sampler and a wavetable oscillator. On top of it the module is able to generate some special effects. A-112 was designed as an additional sound source with the typical sounds of the early 8 bit samplers and is not comparable with the modern polyphonic MIDI samplers available on the market.

Sampling mode: 8 bit audio resolution, 128kB memory in 2 banks 64kB each (equivalent to 2 seconds of sampling time for each bank with 32 kHz sampling rate), audio input with attenuator, overload display in record mode (gate LED), possibility of MIDI Dump to store sounds in a computer via MIDI, non-volatile memory for the 2 samples in the module, manual tune control for adjustment of sampling rate for record and play, CV input (~ 1V/Oct), both manual tune and CV determine the sampling rate respectively the pitch (pitch range is 5 octaves), gate input (not a trigger: the sample starts at the positive edge of the gate signal and is played as long as gate is high or until the end of the sample is reached), manual Gate button, non-filtered audio output (thus quantizing noise can be used as an element of the sound intentionally).

Wavetable mode: special appearance of the sampling mode when playing a sample, the audio input is now used as a second control voltage input for moving through the sample in 256 byte wide loops (wavetables). The control voltage required to move through all wavetables applied to the input "Wave CV In" is in the range -2.5V (wavetable 1) ... 0V (wavetable 127) ... +2.5V (wavetable 256) when control "Atten." is set fully clockwise. To achieve the typical wavetable oscillator sounds the sampling memory must contain corresponding wavetable data (e.g. loaded via MIDI dump). These data contain a set of wavetables with different harmonic content (e.g. a filter sweep) to get the typical wavetable sound while moving through the tables via CV. But you may also use a "normal" sample and go through the sample with CV to obtain partially amazing sounds never heard before. You may use for example sampled speech and go with CV through the syllables or speech shreds to get really very extreme sounds. An ideal addition for this feature is the Offset/Attenuator module A-183-2 which can be used to adjust the position of the wavetable (Offset) and the modulation depth (Att.). The corresponding jumper of the A-183-2 has to be set to bipolar offset (as the A-112 requires -2.5V...+2.5V to pass through all 256 wavetables). As modulation source an LFO (A-145, A-146, A-147, A-143-3), ADSR (A-140, A-141, A-142, A-143-1/2) or a random voltage (A-118, A-149-1) may be used. Even a ribbon controller (A-198 or R2M), the Theremin module A-178, the Joystick A-174 or the Wheels module A-174-2 are useful to drive through the wavetables.

Effects: Additionally, the module offers - in a way free of charge - some effects like delay, reverse delay, pitch shifting or freeze. But it has to be pointed out that due to the 8 bit audio resolution these effects are not comparable to high quality effect units and should be understand as an extra for nothing. The A-112 is not an effects unit!

The sampling time of the A-112 is about 1...30 seconds corresponding to a sampling frequency range of about 60kHz...2kHz (64kB@60kHz ~ 1 s, 64kB@2kHz ~ 30 s).

Technical note: the module uses a battery for the non-volatile storage of the sampling data. Batteries have a limited lifespan and have to be inspected at least every two years. For details please refer to the FAQ page of our website: Lifespan of rechargeable batteries (used for memory backup).

Notes: Module A-148 (Dual S&H) has two identical sample & hold modules, designed to produce 'staircase' voltages. The signal present at the sample input is sampled at a rate set by the signal at the trigger input, and held at that voltage at the S&H output.

The exact shape of the staircase depends on the sort of waveform at the sample input: NOISE or RANDOM signals produce random patterns; an LFO produces rising or falling staircase patterns.

Two LEDs for each S&H indicate the voltage (positive or negative) of the sampled signal.

Notes: A-105-4 is our first polyphonic filter and contains four
identical 24dB Lowpass filters (SSM2044 type). It has
available common manual controls and CV inputs with
attenuators for these parameters:

Frequency (F)

Frequency Modulation Intensity (FM)

Resonance (Q)

Audio Input Level (L)
Each filter has available a separate FM input as well as an Audio Input and Output. The FM input is typically connected to the output of the associated envelope generator (e.g. A-141-4).
The envelope amount for all four filters is controlled by the FM knob and the CVFM input by means of four built-in VCAs, which are controlled by the FM control and CVFM input. This allows also voltage control of the envelope amounts.

In addition common frequency modulation for all filters is possible (e.g. by an LFO). For this the CVF input with attenuator can be used. The range of the audio input level control (L) allows also clipping/distortion with typical A-100 audio levels
(e.g. from A-111-4) at the filter inputs. Even this parameter is voltage controllable as well as the resonance (Q).
Application: polyphonic patches (four VCFs with same parameters).

Notes: A-101-6 is a new filter module that uses so-called opto FET's to control the filter frequency. Opto FET's are very similar to Vactrols, but use light dependent field effect transistors (FET's) instead of light dependent resistors (LDR's). An opto FET is a combination of a light-dependent FET and an LED, both put into a small light-proof case. The advantage, compared to vactrols, is a much faster response of opto FET's compared to LDR's - this allows much faster attack/decay times and even FM effects.

The variable resistors corresponds to the opto FET. The brightness of the Opto FET LED's, and consequently the filter frequency, can be adjusted manually (Frequ. control) and controlled by means of an external control voltage (CV) with attenuator. The LED at the front panel reflects the LED brightness inside the opto FET's.

The type of filter is chosen by jumpers on the PC board (factory setting: low pass). The type of filter determined by the jumpers positions can be marked by means of a water-resistant felt pen at the front panel.

The resonance is controlled by the Feedback control up to self-oscillation. By means of a trimming potentiometer the maximal feedback can be adjusted. High feedback values can be used mainly in the all-pass mode to obtain very extreme self-oscillation sounds. Even an external feedback signal can be used instead of the internal feedback connection (FB In socket). Whenever the filter type is changed by means of the jumpers the trimming potentiometer for the maximal feedback has to be re-adjusted.

The Mix control is used to pan between the original signal (CCW position) and the effect signal (CW position). In filter mode (LP/HP) this control is usually set fully CW. In the all-pass modes one obtains phasing sounds at centre position or "pure" all-pass sound in fully CW position.

Notes: Module A-160-2V is an enhanced version of the standard clock divider A-160. The module is a frequency divider for clock/trigger/gate signals, designed to be a source of lower frequencies, particularly for rhythm uses.

The Clock input will take any digital signal from, eg., an LFO, MIDI sync, or the gate from a MIDI-CV interface. At the outputs, you have access to three sets of seven different sub-divided clock signals, from half the clock frequency down to 1/128. The low/high levels of the output signals are 0V and about +10V.

The A-160-2V also has a reset input. Whenever a reset signal is sensed, all outputs are set to certain levels which depend upon the selected mode.

HP : 4

Notes: Module A-130-8 contains eight linear voltage controlled amplifiers (VCAs). Each VCA features a control voltage input (CV), a signal input (In) and a signal output (Out). In addition three mixers are included: the socket labelled "1-4" outputs the sum of the VCAs 1-4, the socket labelled "5-8" outputs the sum of the VCAs 5-8, the socket labelled "1-8" outputs the sum of all eight VCAs.

The signal inputs are able to process levels up to 10Vpp without clipping. Each CV input is equipped with a trimming potentiometer that is used to adjust the sensitivity of the CV input in question. In the factory the module is adjusted for the CV range 1...+5V but can be re-adjusted by the user for other control voltage ranges (e.g. 0...+10V).

The amplification range for each single VCA is 0...1. The signals of the sum outputs have a lower amplification to avoid distortion.

The VCAs and mixers are fully DC coupled, i.e. the module can be used for the processing of both audio and control voltage signals. The control voltage and signal inputs can be normalled by means of small solder pads (e.g. 1 > 2 > 3 > 4 and so on, or 1 > 5, 2 > 6, 3 > 7, 4 > 8 for the stereo application mentioned below).

Typical applications:

Any kind of VCA application (e.g. voltage controlled attenuation of audio or control voltage signals)
Two voltage controlled mixers with four channels each
Voltage controlled stereo mixer with four channels each, for this the control voltage inputs have to be correspondingly patched or internally normalled: CV1=CV5 / CV2=CV6 / CV3=CV7 / CV4=CV8
Voltage controlled mixer with eight channels
Add-on for the planned Joystick module A-174-4

Dimensions
6 HP
40 mm deep

Current Draw
50 mA +12V
50 mA -12V
0 mA 5V

Notes: The Doepfer A-126-2exp is an expander for the A-126-2 Voltage Controlled Frequency Shifter.

It adds two outputs from the Dome filter (+45 and -45 degrees) as well as separate outputs from the ring modulators 1 and 2, and from the internal envelope generator. Furthermore, it offers dedicated outputs for Up and Down Shift, allowing the module to be patched in stereo.

*Note: The expander can only be used in conjunction with the module A-126-2.

HP : 2

Notes: The Doepfer A-126-2exp is an expander for the A-126-2 Voltage Controlled Frequency Shifter.

It adds two outputs from the Dome filter (+45 and -45 degrees) as well as separate outputs from the ring modulators 1 and 2, and from the internal envelope generator. Furthermore, it offers dedicated outputs for Up and Down Shift, allowing the module to be patched in stereo.

*Note: The expander can only be used in conjunction with the module A-126-2.

HP : 2

Notes: Module A-126-2 is a fully analog frequency shifter for audio signals. A frequency shifter is an audio processing unit that shifts each frequency of the incoming audio signal by the same frequency. If the shifting frequency is e.g. 200Hz an incoming audio frequency of 1000 Hz becomes 1200 Hz, 2000Hz becomes 2200 Hz, 3000 Hz becomes 3200 Hz and so on. Pay attention that this is different from pitch shifting where all frequencies are shifted proportional (e.g. 1000>1200Hz, 2000>2400Hz, 3000>3600Hz) !
The frequency range of the internal quadrature VCO is about 8 octaves (about 20Hz ... 5kHz). If required an external quadrature VCO can be used.

The module is equipped with these controls, inputs and outputs:

Frequ. 1: first manual control of the shifting frequency (factory setting: coarse, range about 20Hz - 5 kHz)

Frequ. 2: second manual control of the shifting frequency (factory setting: fine)

by means of internal jumpers the sensitivity of Frequ.1 and 2 can be swapped (i.e. Frequ.1 = fine and Frequ.2 = coarse)

the relation between coarse and fine control is about 25:1 (corresponding to about 8 octaves to 1/3 octave)

FCV In (socket) and FCV (small control without knob): control voltage input with attenuator for the external voltage control of the shifting frequency

Mix: manual control of the up/down shift panning unit, fully CCW = down shift, fully CW = up shift, in between a mixture of down and up

Mix CV In (socket) and Mix CV (small control without knob): control voltage input with attenuator for the mixing unit for external voltage control of the up/down mixing

Audio In (socket), Level (small control without knob) and Overload (LED): audio input with attenuator, typ. audio in level = 1Vpp, the level control has to be adjusted so that the overload LED just begins to light up a bit, when the LED is fully on clipping/distortion occurs, when the LED is permanently off the input level is too low and the signal-to-noise ratio increases

Audio Out (socket): audio output of the frequency shifter

Squelch (small control without knob): controls the squelch function: fully CCW (Env.) the output VCA is controlled by the envelope signal, which is derived from the audio input signal, fully CW (open) the output VCA is permanently open (no squelch function), in between the squelch intensity can be adjusted

Quadrature VCO Outputs (sockets Sin and Cos): outputs of the internal quadrature oscillator, about 12Vpp level (+6V/-6V)

Ext. Inputs Sin and Cos (sockets): required when an external quadrature VCO (e.g. A-143-9 with a wider frequency range or A-110-4 with thru zero feature or A-110-6 with different waveforms) is used instead of the internal quadrature VCO, the levels of the external VCO should be about 10Vpp (8...10Vpp are OK) and the signals have to be symmetrical around zero Volts, the sockets are normalled to the internal quadrature VCO (i.e. the sockets are equipped with switching contacts that interrupt the internal connection as soon as a plug inserted)

VCA ext. CV (socket): used when an external control voltage (e.g. from an envelope generator) should be used to control the output VCA instead of the internal squelch unit, the socket is normalled to the output of the squelch control (i.e. the socket is equipped with a switching contact that interrupts the internal squelch connection as soon as a plug inserted). From about +8V external control voltage the VCA is fully open.

Internal terminals (pin headers, e.g. for a DIY breakout module):

envelope follower output

dome filter output 1

dome filter output 2

ring modulator 1 output

ring modulator 2 output

Up shift output

Down shift output

Notes: Module A-179-2 can be used to convert different illumination intensities into corresponding analog voltages and a gate signal derived from the analog voltage. It's the successor of the obsolete module A-179.
A light sensitive resistor (LDR) converts the illumination of the internal light sensor into a corresponding analog control voltage. The internal sensor is located at the front panel. Instead of the internal sensor a remote sensor can be connected via a standard patch cable to the module (ext.Sens. socket). An external sensor with a 2 m patch cable (A-100C200) is included. The external sensor is mounted on a small pc board which is equipped also with a 3.5 mm jack socket. The nut of the socket can also be used to mount the external sensor.

The module A-179 is similar to the Theremin module A-178 but uses the illumination intensity instead of the distance between hand and antenna for generating the analog voltage.
One can choose between passive control by covering/shading the sensor via hand or body, or active control by using e.g. a pocket lamp or flashlight. For this two versions of output voltages are available (CV Out + und CV Out -).

The module has these controls and in/outputs available:

ext. Sens.: by means of a standard patch cable the external sensor can be connected to this socket. In this case the internal sensor is turned off.

CV Offset: control to adjust the output voltage which is assigned to a certain illumination (e.g. 0V for complete darkness)

CV Level: control that is used to adjust the sensitivity of the generated output voltage (i.e. how much a certain difference in brightness affects the output voltage)

Gate Threshold: control that is used to adjust the threshold for the generation of the gate signal, an internal jumper is used to define if the gate signal is derived from the CV Out+ or CV Out- voltage.

CV Out+: positive control voltage output, increasing brighness causes the increase of the voltage at this output

CV Out+: negative control voltage output, increasing brighness causes the decrease of the voltage at this output

LED CV Out: bipolar LED (red/yellow) as display for the CV outputs

Gate: gate output with LED display

Applications:

controlling any voltage controlled parameter e.g. pitch or pulswidth of a VCO, filter frequency or resonance of a VCF, loudness of a VCA, time of an envelope generator, frequency of a VCLFO
triggering activities via gate with adjustable threshold, e.g. starting an envelope, starting/stopping a sequencer or any switching function (e.g. with A-150-1 or 151).
Conversion into MIDI control change messages is possible with the A-192-2.

Width: 4 HP / 20.0 mm
Depth: 30mm (measured from the rear side of the front panel)

Notes: Module A-101-8 is a 8-stage phase shifter which uses light-sensitive resistors (LDR) and is a replica of the Compact Phasing A manufactured by the company Schulte in the seventies. The actual phasing circuit is identical to the historic model. Only the illumination control of the LDRs is different: the A-101-8 uses LEDs to illuminate the LDRs, the historic model used incandescent miniature lamps. And the A-101-8 has no built-in LFO but can be controlled by any external control voltage source (e.g. LFO, ADSR, random, Theremin, ribbon controller, sequencer, midi). The phasing offset (i.e. the base value for the phase shifting) and the modulation depth of the external control signal can be adjusted separately. The Compact Phasing A had no offset control but only a depth control for the built-in LFO. Feedback and mixing ratio of the output signal are set by two controls. The audio input is equipped with an attenuator. The module has two audio outputs available (same as the historic model) and a visual display of the phase shifting.

The module has these controls and in/outputs available:

Control Man. : manual control of the phase shift offset (base value)

Control CV: attenuator for the signal applied to the CV socket

Control Feedb.: Feedback or Resonance (similar function as filter resonance/feedback/emphasis)

Control Mix: sets the mixing ratio between original and phase shift signal appearing at output 1

fully CCW: only the modified input signal appears at output 1 (see note below *)

center: a mixture between the modified input signal and the phase shift signal appears at output 1, that's the standard position for the classical phasing effect

fully CW: the pure phase shifted signal appears at output 1 (e.g. for vibrato effects)

Control Input Level: attenuator for signal applied to the In socket

Socket In: audio input

Socket CV: control voltage input

Socket Out 1: audio output 1 (mix signal)

Socket Out 2: audio output 2 (modified input signal)

LED: visual control of the phase shift

The module has some peculiarities (same as the historic model):

The input signal is processed at first by a pre-stage which outputs a "modified" input signal (*). This signal is not processed by the phase shift stages but is affected by the feedback setting. Only when feedback is set to zero this signal is identical to the input signal. Otherwise it contains feedback components.

This signal is output on socket Out 2.

When both output sockets Out 1 and Out 2 are used as stereo channels one obtains a spatial stereo sound effect.

The same signals is also used for the CCW position of the mix control. With mix control fully CCW the unmodified signal appears only if the feedback control is set to zero. Otherwise it contains feedback components.

The historic model had two audio inputs: one 5-pin DIN socket and a 1/4" jack socket. The DIN socket was intended for high-level line signals. When the 1/4" jack socket was used the amplification of the pre-stage increased by about 100. The 1/4" jack socket was intended for low level signals (e.g. electric guitars or microphones). For this feature the A-101-8 has an internal jumper that can be used to increase the amplification. As long as the module is used within the A-100 system usually the lower amplification is used to avoid distortion.

The 8 photo resistors and LEDs are assembled within an small lighproof box. In addition the pc boards are made of lighproof black material to avoid interfering light from other modules or the bus board.

Dimensions
4 HP
45 mm deep

Current Draw
30 mA +12V
30 mA -12V

Notes: ***B-STOCK: Box opened, but product is in excellent condition and in perfect working order***


Module A-121s is a dual multimode filter which can be used for stereo applications as well as for parallel or serial organized dual mono filters. The core is a 12dB multimode filter identical to the modules A-121-2 and A-121-3. The selection of the filter type is continuously from lowpass via notch and highpass to bandpass. We attached great importance to the usability of the manual controls and CV inputs for both stereo and dual mono applications. For the filter parameters frequency (F), resonance (Q) and type (T) common controls and CV inputs as well as single controls and CV inputs are available. For the filter frequency in addition a manual control and CV input for the filter spread (frequency difference or delta F) is available.

Controls:
F: master frequency control for both filters (large knob)
Type 1 / Type 2: filter type panning/morphing L-N-H-B
Link to 1: Toggle switch so that Type 1 also controls type of filter 2 (i.e. simultaneous filter type control for both filters)
SFM1 / SFM2: Single Frequency Modulation controls (polarizers), connected to the corresponding sockets SFM1/SFM2 (socket SFM1 is normalled to a fixed positive voltage, SFM2 is normalled to SFM1, that way the controls SFM1/SFM2 work as frequency controls for each filter provided that no modulation signals are patched to the SFM1/SFM2 sockets)
CFM: common frequency control, controls two VC-polarizers which process the signals connected to the two sockets CFM1/CFM2, CFM2 is normalled to CFM1, that way also the same modulation signal (e.g. an envelope generator) can be used for both filters and the level controlled simultaneously by the CFM control
Delta F: controls the difference between the frequencies of the two filters manually (frequency "spread"), at centre position the frequencies are the same
Delta FM: controls the level of the Delta FM signal (socket), which allows to control the spread between the frequencies also by an external control voltage (e.g. by an LFO or ADSR)
Q: controls the resonance of both filters simultaneously
Level 1 / Level 2: attenuators for the two audio inputs
QM/TM1, QM/TM2: attenuators for the modulation inputs QM/TM1 and QM/TM2

Sockets:
In1 / In2: audio inputs (In2 is normalled to In1)
Out1 / Out2: audio outputs
F: common frequency control input for both filters (~ 1V/oct)
Delta FM: Control voltage for frequency spread, processed by the polarizer Delta FM
SFM1 / SFM2: single frequency modulation inputs, processed by the polarizers SFM1 and SFM2, SFM1 is normalled to a fixed positive voltage, SFM2 is normalled to SFM1#
CFM1 / CFM2: common frequency modulation inputs, processed by the two voltage controlled polarizers controlled by CFM knob, CFM2 is normalled to CFM1
QM/TM1, QM/TM2: the addressing of these sockets/attenuators is defined by internal jumpers. QM means Q modulation (i.e. resonance modulation), TM means filter type modulation (QM1 = resonance modulation filter 1, QM2 = resonance modulation filter 2, TM1 = filter type modulation filter 1, TM2 = filter type modulation filter 2), socket QM/TM1 is normalled to a fixed positive voltage, QM/TM2 is normalled to QM/TM1
A 45 degrees triangle next to a socket means that the switching contact of the socket is normalled to a fixed positive voltage (SFM1, QM/TM1).
A vertical triangle indicates the normalling of two sockets (In1>In2, SFM1>SFM2, CFM1>CFM2, QM/TM1>QM/TM2).

If the filters do not behave as expected please pay attention to these peculiarities:

For the controls SFM1, SFM2, CFM, Delta F and Delta FM the centre position is the neutral position as these are polarizers. If the filter behaves unexpected these controls should be set to centre positions for the time being.

For the controls F, Q, Level 1, Level 2, QM/TM1 und QM/TM2 the fully CCW position is the neutral position as these are standard attenuators. If the filter behaves unexpected at least the controls QM/TM1 and QM/TM2 should be set to fully CCW. Via the normalling of the sockets QM/TM1 and QM/TM2 and the associated controls the filter parameters adjusted by the major controls (e.g. Type 1, Type 2 or Q) may be overwritten.

By means of small circles at the bottom right side of the front panel the user can mark the function of the QM/TM inputs. These assignments are possible:
QM/TM1 controls QM1, QM/TM2 controls QM2, the filter types are not controlled by external CVs
QM/TM1 controls TM1, QM/TM2 controls TM2, the resonances are not controlled by external CVs
QM/TM1 controls QM1 and QM2 simultaneously, QM/TM2 controls TM1 and TM2 simultaneously

Notes: Module A-197-3 is a control unit for RGB LED stripes. The LED stripe is glued e.g. to the inner edges of the cases A-100P6/P9/PMS6/PMS9/PMS12 to illuminate the modules and patching statically or dynamically. Especially during live events the dynamic illumination in sync with the sound is an eye-catcher. Each colour (red, green, blue) has available a manual control for the background brightness and a CV input with attenuator that enables the dynamic brightness controlled by other control voltages of the modular system. For example three envelopes can be used which also control the loudness or filtering of sound processing modules. But even other control applications are possible, e.g. LFO, random voltages, clock/gate/trigger signals, sequencer, Midi-to-CV.

Notes: Bus board to connect 14 modules

An assembled and tested bus board, 22 sockets, e.g. for customers who want to built their own case and need a bus board for A-100 modules, includes cables for connection to +/-12V power supply (4 wires with flat connectors on both ends, length about 30cm), but no mechanical parts (e.g. screws, spacers, nuts, washers).

In the new version of the A-100 bus board (labeled Version 6 / 2019) boxed pin headers are used which are equipped with a reverse protection (gap for the "nose" of the socket of the bus cable). When the bus cable coming from the module is connected to the boxed header in question the "nose" has to point to the right. The polarity of the cable is correct if the red wire of the bus cable then points to the bottom (to the continuous line labeled"RED WIRE" on the pc board). If this is not the case please do not connect the module to the bus board ! Otherwise both the module and the power supply (A-100PSU3) may be damaged ! In that case please contact the manufacturer of the module and ask for a suitable bus cable with the correct polarity of the connector.

The bus cables of original A-100 modules manufactured by Doepfer are equipped with suitable bus cables since 2012. Only for older A-100 modules manufactured before 2012 it may happen that the polarity of the 16 pin female connector of the bus cable is wrong (nose points to the left when red wire points to the bottom). This is because in the past unboxed pin headers were used and the position of the "nose" did not matter. In such a case please contact Doepfer or one of their dealers and order a suitable bus cable.

Notes: A fully modular, Eurorack-format version of the excellent Dark Energy synth, the A-111-5 offers VCO, VCF, LFOs, VCA and envelope generator in a compact format. Brilliant value for a starter system.

Supplier's Notes:
Module A-111-5 is a complete monophonic synthesizer module that includes these components (modular version of Dark Energy):

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 ... 12kHz - FM (frequency modulation) control with modulation source switch (LFO1 / off / ADSR)
Manual pulsewidth control for rectangle waveform
PWM control with modulation source switch (LFO2 / off / ADSR)
Waveform switch (sawtooth / off / triangle)
The sum of the waveform chosen by this switch and the rectangle is fed into the VCF (to turn the rectangle off the PW control has to be set fully CCW)
External CV input for VCO frequency (1V/octave)
External CV input for external PWM of the rectangle - internal CV input for frequency (1V/octave) connected to the A-100 bus via jumper, the jumper can be used to interrupt this internal connection if not wanted

VCF
24 dB low pass
~ 12 octaves frequency range
Manual frequency control
Tracking switch half - off - full (internally connected to the external frequency CV input of the VCO, i.e. the VCF tracks to the VCO if the switch is set to "half" or "full" position)
XM: exponential FM (frequency modulation) control with modulation source switch (LFO2 / off / ADSR)
LM: linear FM (frequency modulation) control to modulate the VCF by the triangle of the VCO in a linear (!) manner
Manual resonance control (up to self oscillation)
External audio input (this signal is added to the VCO signal)
External CV input for filter frequency - 1V/octave tracking for usage of the VCF as a sine wave oscillator (not as precise as the VCO but much better than most of the other filters)
VCA
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 VCA)
LFO1 and LFO2
Manual frequency control
Waveform switch (triangle / off / rectangle)
Range switch (low, audio, medium) - LED display (dual green/red color for positive/negative share of the signal)
The inverted LFO1 signal is available as an additional socket (to use the LFO1 signal for external modules)
An internal jumper can be used to select between the LFO1 signal or the inverted LFO1 signal

ADSR
Manual controls for Attack, Decay, Sustain, Release
Range switch (long, short, medium) - blue LED display
ADSR signal is available as an additional socket (to use the ADSR signal for external modules)
Gate input connected to the A-100 bus via jumper, the jumper can be used to interrupt this internal connection if not wanted

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. The sine can be modulated in a linear manner from the triangle wave of the VCO and by LFO2 in an exponential manner at the same time !

From the factory the socket labelled "LFO1" outputs the inverted LFO1 signal. But as the module has several internal pin headers available even another signal may appear at this socket by changing the internal module patch. These six pin headers are available: LFO1 output, LFO2 output, ADSR output, inverter input, inverter output, output socket. The internal default patch is LFO1 -> inverter input, inverter output -> output socket (i.e. socket = inverted LFO1). But even another signal can be patched to this socket (e.g. inverted ADSR, non-inverted LFO1, inverted or non-inverted LFO2). It is also possible to add a blind panel next to the A-111-5 with a couple of sockets that are connected to the corresponding pins of the A-111-5 pc board. The in- and outputs of the VCO, VCF and VCA are not available as pin headers because the VCO, VCF and VCA are internally connected in the circuit which is used in this module.

Notes: Module A-105-2V is a voltage controlled low pass filter with 24dB/octave slope.

It is the successor of the A-105 which had to be discontinued because the obsolete SSM2044 filter circuit. The A-105-2 is based on the SSI2144 which is in turn the successor circuit of the SSM2044. The features of both modules are nearly the same. The main difference is the clearly reduced front panel width of the A-105-2 (4HP instead of 8HP) and the associated changes of the controls and sockets positions. In addition the A-105-2 is equipped with 2 audio inputs.

The module has these controls and in/outputs available:

Control Frequ: manual frequency control
Control FCV2: attenuator for the frequency control voltage applied to socket FCV2
Control Q: manual resonance control
Control QCV: attenuator for the resonance control voltage applied to socket QCV
Control Input 1 Level: attenuator for the audio input signal applied to socket Input 1
Socket Input 1: audio input 1 (with attenuator)
Socket Input 2: audio input 2 (without attenuator)
Socket FCV1: frequency control voltage 1 (without attenuator, about 1V/oct scale)
Socket FCV2: frequency control voltage 2 (with attenuator)
Socket QCV: resonance control voltage (with attenuator)
Socket Out: audio output
Technical notes:

Frequency range: about 15Hz ... 15 kHz
Resonance up to self oscillation
Max. input voltage at Input 2 without clipping/distortion: about 15Vpp
Max. output voltage without clipping/distortion: about 15Vpp
The signals of both inputs are mixed before they are processed by the filter. This saves an external mixer for small setups.
Depth: 45 mm

HP : 4

Notes: Module A-130-2v is composed of two identical voltage controlled amplifiers (VCA). Each VCA has a manual gain control (also named Initial Gain) and a control voltage input with attenuator. The character of the control scale can be switched to linear or exponential. All inputs and outputs are DC coupled. Consequently the VCAs can be used to process both audio and control voltages (e.g. for voltage control of the level of LFO or envelope signals). The signal input has no attenuator available but is capable to process up to 16Vpp signals (i.e. -8V...+8V) without distortion. For the processing of higher levels an external attenuator (e.g. A-183-1) is recommended.

The amplification range is 0...1. Even with a higher external control voltage the amplification remains at 1 (kind of "amplification clipping" at 1).

Controls (for each of both units):

Gain: manual gain control (Initial Gain) in the range 0...1
CV: attenuator for the CV input
lin/exp: switches the VCA characteristic to linear or exponential, in center position the VCA is off (mute function)
Inputs and outputs (for each of both units):

CV: control voltage input, min. +5V required for max. amplification (1) with CV control fully CW and Gain fully CCW
In: signal input, max. 16Vpp (+8V...-8V) without distortion
Out: signal output

A-130-2v is the slim version of module A-132-3 and offers essentially the same features. But the distances between the controls are smaller and rubberized small-sized knobs are used. In return the front panel has 4 HP only which is half the width of the A-132-3. The module is primarily planned for applications where only limited space is available.

Power consumption: 30mA at +12V and 30mA at -12V

Depth: 50mm

HP : 4

Notes: VCO:

- Tune: manual tune control (with an internal jumper the range can be set to ~ +/-1 half an octave or ~ +/-2.5 octaves)
- Oct: range switch -1 / 0 / +1 octave
- Mod: modulation depth (attenuator wired to the Mod. socket)
- Dest: switch that is used to address the modulation to frequency modulation (position FM) or pulsewidth modulation (positon PM), in centre positon no modulation
- PW: manual pulsewidth control for rectangle waveform, PW can be also modulated by the Mod. input as mentioned above
- Wave: waveform switch (sawtooth / off / triangle), the sum of the waveform chosen by this switch and the rectangle is fed into the VCF (to turn the rectangle off the PW control has to be set fully CCW or fully CW)
- 1V/Oct. (socket): external CV input for VCO frequency (1V/octave)
- Access to internal bus CV (via jumper, optional, please remove the bus jumper if this feature is not used to avoid unwanted frequency modulation as then the unused CV line of the bus works as a kind of antenna)
- Triangle core VCO, frequency range about 32Hz ... 8kHz

Balance unit:

- The balance unit is made of two VCAs which are controlled by the sum of manual Balance control and the balance CV input in the opposite direction.
- The audio input of VCA1 is hard-wired to the VCO output, audio input 2 is connected to the socket Ext.In.
- The output of the balance unit is used as audio input for the VCF
- Bal.: manual balance control, fully CCW the internal VCO is used, fully CW the external signal (Ext.In) is used, at centre position both signals have about the same level
- CV Bal.: CV input for balance (range about 0...+5V)
- Ext. In: external audio input for VCA2, about 5 Vpp level required for similar loudness as the internal VCO
- This socket is normalled to the internal VCO suboctave f/2 signal (rectangle with half the frequency), if no external signal is applied the suboctave signal is used as the second signal for the balance unit

VCF:

- 24 dB low pass
- Frq: manual frequency control
- FM1: frequency modulation depth (attenuator wired to the VCF FM1 socket, the socket is normalled to the internal Envelope signal and then FM1 controls the modulation depth of the internal envelope applied to the filter)
- FM2 (socket) : second CV input for VCF without attenuator (about 1V/octave), can be used e.g. for VCF tracking by connecting the same CV which is used also for the VCO frequency
- Res: manual resonance control (up to self oscillation)
- If the VCO is turned off (waveform switch = centre position, pulsewidth control = fully CCW or CW) and the VCF resonance is set to maximum the module can be used as a sine oscillator, the tracking at socket VCF FM2 is about 1V/octave (not as precise as the VCO but much better than most other filters)
- ~ 11 octaves frequency range (~ 10 Hz ... 20kHz)

VCA:

- Gain: manual amplitude control (initial gain), can be used to open the VCA without envelope signal
- VCA (switch): used to switch between gate and envelope as control signal for the VCA, in centre position the VCA is not controlled by envelope or gate
- Note: when gate is used the VCA is controlled directly by the gate signal (i.e. hard on/off), this may lead to clicking noise under certain conditions (especially with low VCO/VCF frequencies)
- 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
- Out: audio output of the module (= VCA output)

Envelope:

- Gate (socket): Gate input (min. +5V), can be normalled to the bus gate signal by means of a jumper
- Att: manual control for Attack
- D/R: manual control for Decay/Release
- Env. (switch): used to switch between A/D, ADSR and A/R mode of the envelope generator, in centre position (ADSR) the sustain level is fixed to about 50%
- Envelope (socket): envelope output (about +10V)
- CVT (socket): CV input for time control, by means of two internal jumpers one can select which time parameters are controlled by the CVT input (e.g. A only or D/R only or A/D/R) and in which direction (i.e. if an increasing CVT shortens or stretches the time parameter in question)
- Envelope LED display
- Attack time range: ~ 1ms ... 5 sec (can be extended by using the CVT input)
- Decay/Release time range: ~ 1ms ... 15 sec (can be extended by using the CVT input)

Notes: ***B-STOCK: Item refurbished, repaired and in perfect working order.***


A-138s is a simple but useful 4-in-2 mixing tool. It has four inputs available. Each input is equipped with an attenuator (Level) and a panning control that is used to distribute the signal to the left and right output. Beyond stereo mixing it is equally suited to create variable parallel routings. For example: Any of the four inputs may be routed in variable intensity to feed two filters.

You may regard the A-138s as a smaller version of the A-138m Matrix Mixer.

Inputs and outputs are DC coupled, i.e. the module can be used for the mixing of control signals too.

- 3U Eurorack module, 8 HP wide, 30 mm in depth
- Power consumption: 10 mA at +12 V and 10 mA at -12 V

Notes: The new basic system 3 from Doepfer is a return to Dieter Doepfer's original vision of analogue modular synthesis. Modules can be connected via front panel audio and CV connectors and used in infinite combinations. The Basic System 3 is an easily accessible and well-structured system that can be used by enthusiasts and beginners alike. It can be used as a base for exploring sound synthesis and electronic sounds, or as a supplement to delve deeper into different types of synthesis. For example, it is possible to create 4-part paraphonic patches or create complex sounds using the ring modulator. Percussion and drum sounds can also be created in a variety of ways alongside the classic synth sounds. The system's two filters can also be set to self-resonance to provide additional sound sources. The Waveshaper can be used to modify simple sounds and change their overall timbre. As each user's personal requirements are different, blank panels are installed that can be replaced with modules. This means there is no need to buy a new cabinet.

The following modules are included in the basic system 3:

1x A-108 6/12/24/48dB Low Pass Filter
2x A-110-1 Standard VCO
1x A-118 Noise / Random
1x A-121-2 Multimode Filter
1x A-131 VCA exponential
1x A-132-3 Dual linear/exponential VCA
1x A-137-1 Wave Multiplier I
1x A-138j Inverting/Interrupting Mixer (Janus Mixer)
1x A-138b Mixer logarithm.
1x A-138s Mini Stereo Mixer
1x A-140 ADSR Envelope Generator
1x A-140-2 Dual Mini-ADSR
1x A-147-4 Dual VCLFO
1x A-151 Quad Sequential Switch
1x A-160-2 Clock Divider II
1x A-171-2 VC Slew Processor / Generator
2x A-180-2 Multiples 1
1x A-184-1 Ring Modulator/S+H/T+H/Slew Limiter
5x Blind Panel 4HP

The following Patch cables are included:

5x A-100C15 Cable 15cm yellow
10x A-100C30 Cable 30cm black
15x A-100C50 Cable 50cm grey
5x A-100C80 Cable 80cm red

Notes: ***B-STOCK: Slight dent om the edge, otherwise in perfect condition***


VCO:

- Tune: manual tune control (with an internal jumper the range can be set to ~ +/-1 half an octave or ~ +/-2.5 octaves)
- Oct: range switch -1 / 0 / +1 octave
- Mod: modulation depth (attenuator wired to the Mod. socket)
- Dest: switch that is used to address the modulation to frequency modulation (position FM) or pulsewidth modulation (positon PM), in centre positon no modulation
- PW: manual pulsewidth control for rectangle waveform, PW can be also modulated by the Mod. input as mentioned above
- Wave: waveform switch (sawtooth / off / triangle), the sum of the waveform chosen by this switch and the rectangle is fed into the VCF (to turn the rectangle off the PW control has to be set fully CCW or fully CW)
- 1V/Oct. (socket): external CV input for VCO frequency (1V/octave)
- Access to internal bus CV (via jumper, optional, please remove the bus jumper if this feature is not used to avoid unwanted frequency modulation as then the unused CV line of the bus works as a kind of antenna)
- Triangle core VCO, frequency range about 32Hz ... 8kHz

Balance unit:

- The balance unit is made of two VCAs which are controlled by the sum of manual Balance control and the balance CV input in the opposite direction.
- The audio input of VCA1 is hard-wired to the VCO output, audio input 2 is connected to the socket Ext.In.
- The output of the balance unit is used as audio input for the VCF
- Bal.: manual balance control, fully CCW the internal VCO is used, fully CW the external signal (Ext.In) is used, at centre position both signals have about the same level
- CV Bal.: CV input for balance (range about 0...+5V)
- Ext. In: external audio input for VCA2, about 5 Vpp level required for similar loudness as the internal VCO
- This socket is normalled to the internal VCO suboctave f/2 signal (rectangle with half the frequency), if no external signal is applied the suboctave signal is used as the second signal for the balance unit

VCF:

- 24 dB low pass
- Frq: manual frequency control
- FM1: frequency modulation depth (attenuator wired to the VCF FM1 socket, the socket is normalled to the internal Envelope signal and then FM1 controls the modulation depth of the internal envelope applied to the filter)
- FM2 (socket) : second CV input for VCF without attenuator (about 1V/octave), can be used e.g. for VCF tracking by connecting the same CV which is used also for the VCO frequency
- Res: manual resonance control (up to self oscillation)
- If the VCO is turned off (waveform switch = centre position, pulsewidth control = fully CCW or CW) and the VCF resonance is set to maximum the module can be used as a sine oscillator, the tracking at socket VCF FM2 is about 1V/octave (not as precise as the VCO but much better than most other filters)
- ~ 11 octaves frequency range (~ 10 Hz ... 20kHz)

VCA:

- Gain: manual amplitude control (initial gain), can be used to open the VCA without envelope signal
- VCA (switch): used to switch between gate and envelope as control signal for the VCA, in centre position the VCA is not controlled by envelope or gate
- Note: when gate is used the VCA is controlled directly by the gate signal (i.e. hard on/off), this may lead to clicking noise under certain conditions (especially with low VCO/VCF frequencies)
- 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
- Out: audio output of the module (= VCA output)

Envelope:

- Gate (socket): Gate input (min. +5V), can be normalled to the bus gate signal by means of a jumper
- Att: manual control for Attack
- D/R: manual control for Decay/Release
- Env. (switch): used to switch between A/D, ADSR and A/R mode of the envelope generator, in centre position (ADSR) the sustain level is fixed to about 50%
- Envelope (socket): envelope output (about +10V)
- CVT (socket): CV input for time control, by means of two internal jumpers one can select which time parameters are controlled by the CVT input (e.g. A only or D/R only or A/D/R) and in which direction (i.e. if an increasing CVT shortens or stretches the time parameter in question)
- Envelope LED display
- Attack time range: ~ 1ms ... 5 sec (can be extended by using the CVT input)
- Decay/Release time range: ~ 1ms ... 15 sec (can be extended by using the CVT input)

Notes: Module A-119 (External Input / Envelope Follower) is designed to allow external audio signals to be integrated into the System A-100. It comprises a pre-amp, envelope follower, and comparator.

The pre-amp has two inputs: an unbalanced input for line level signals, with a gain factor of from 0 to 20, and a balanced input with a gain factor of from 0 to 500, for insertion of low level signals, for instance from a microphone or electric guitar.

The Envelope Follower reads the signal level of the input, and puts out a proportional voltage as an envelope at its own output.

The comparator generates a gate signal whenever the input goes above an adjustable trigger threshold.

Three LED's help you keep track of overload, the envelope, and the gate signal.

Notes: Module A-180-3 is a dual buffered 1-in-3 multiple. The signal applied to the input socket appears as a buffered signal at the three output sockets. Each output has its own buffer, i.e. the three output sockets are not simply connected to each other. The lower output of the upper unit is normalled in the factory to the input of the lower unit. That way the module works as a single 1-in-6 buffered multiple provided that no signal is applied to the input of the lower unit. But it's also possible to pick-up the bus CV and normalize the input socket of the lower unit to the bus CV.

Application: copying/buffering of CV, gate and audio signals.

Notes: 'Vintage' black panel version of Doepfer's updated frequency shifter module, offering weird and wonderful effects by shifting all frequencies by a fixed amount. Unique sound, not to be confused with pitch shifting.

Supplier's Notes:
Module A-126-2 is a fully analog frequency shifter for audio signals. A frequency shifter is an audio processing unit that shifts each frequency of the incoming audio signal by the same frequency. If the shifting frequency is e.g. 200Hz an incoming audio frequency of 1000 Hz becomes 1200 Hz, 2000Hz becomes 2200 Hz, 3000 Hz becomes 3200 Hz and so on. Pay attention that this is different from pitch shifting where all frequencies are shifted proportional (e.g. 1000>1200Hz, 2000>2400Hz, 3000>3600Hz) !
The frequency range of the internal quadrature VCO is about 8 octaves (about 20Hz ... 5kHz). If required an external quadrature VCO can be used.

The module is equipped with these controls, inputs and outputs:

Frequ. 1: first manual control of the shifting frequency (factory setting: coarse, range about 20Hz - 5 kHz)

Frequ. 2: second manual control of the shifting frequency (factory setting: fine)

by means of internal jumpers the sensitivity of Frequ.1 and 2 can be swapped (i.e. Frequ.1 = fine and Frequ.2 = coarse)

the relation between coarse and fine control is about 25:1 (corresponding to about 8 octaves to 1/3 octave)

FCV In (socket) and FCV (small control without knob): control voltage input with attenuator for the external voltage control of the shifting frequency

Mix: manual control of the up/down shift panning unit, fully CCW = down shift, fully CW = up shift, in between a mixture of down and up

Mix CV In (socket) and Mix CV (small control without knob): control voltage input with attenuator for the mixing unit for external voltage control of the up/down mixing

Audio In (socket), Level (small control without knob) and Overload (LED): audio input with attenuator, typ. audio in level = 1Vpp, the level control has to be adjusted so that the overload LED just begins to light up a bit, when the LED is fully on clipping/distortion occurs, when the LED is permanently off the input level is too low and the signal-to-noise ratio increases

Audio Out (socket): audio output of the frequency shifter

Squelch (small control without knob): controls the squelch function: fully CCW (Env.) the output VCA is controlled by the envelope signal, which is derived from the audio input signal, fully CW (open) the output VCA is permanently open (no squelch function), in between the squelch intensity can be adjusted

Quadrature VCO Outputs (sockets Sin and Cos): outputs of the internal quadrature oscillator, about 12Vpp level (+6V/-6V)

Ext. Inputs Sin and Cos (sockets): required when an external quadrature VCO (e.g. A-143-9 with a wider frequency range or A-110-4 with thru zero feature or A-110-6 with different waveforms) is used instead of the internal quadrature VCO, the levels of the external VCO should be about 10Vpp (8...10Vpp are OK) and the signals have to be symmetrical around zero Volts, the sockets are normalled to the internal quadrature VCO (i.e. the sockets are equipped with switching contacts that interrupt the internal connection as soon as a plug inserted)

VCA ext. CV (socket): used when an external control voltage (e.g. from an envelope generator) should be used to control the output VCA instead of the internal squelch unit, the socket is normalled to the output of the squelch control (i.e. the socket is equipped with a switching contact that interrupts the internal squelch connection as soon as a plug inserted). From about +8V external control voltage the VCA is fully open.

Internal terminals (pin headers, e.g. for a DIY breakout module):

envelope follower output

dome filter output 1

dome filter output 2

ring modulator 1 output

ring modulator 2 output

Up shift output

Down shift output

Notes: The module contains two ADSR type voltage controlled envelope generators with exponential curve shapes (charge/discharge curves of a capacitor) behind a front panel with 8 HP only.

Each ADSR provides these controls and in/outputs:

- LED (displays the envelope output)
- A: manual Attack control
- D: manual Decay control
- S: manual Sustain control
- R: manual Release control
- Gate Input
- Retrigger Input
- CVT Input with attenuator (CVT = CV Time)
- Envelope Output 1
- Envelope Output 2

The output voltage range for each envelope is 0 - 10V (10V = attack peak).

The time range of Attack/Decay/Release is about 1ms to 30s.

By means of internal jumpers one can select which time parameters are controlled by the CVT input (e.g. D only or D+R or A+D+R) and in which direction (i.e. if an increasing CVT shortens or stretches the time parameter in question).

Socket CVT can be normalled to an internal fixed voltage (i.e. the switching contact is connected to an internal fixed voltage). That way it's possible to change all time parameters simultaneously by means of the CVT control.

Another jumper is used to set output 2 to normal or inverted envelope.

And another jumper is used for the normalling of Gate 2 to Gate 1 (i.e. ADSR#2 is also triggered by Gate 1).

Two more jumpers are used for the optional bus access to the gate signal of the bus for each ADSR.