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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: 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. Red finish.

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

Notes: High quality rotary knob, for use with Doepfer or a wide range of modules. Robust design with indented edges. Yellow 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: Blank panel, 1HP, constructed from anodised aluminium, silver.

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

Notes: Blank panel, 2HP, 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: The A-100LC1v is a smaller version of the A-100LC3 with 48 HP of space. It is made out of raw wood, a black coating gives the Eurorack frame a vintage look. The built-in power supply, type A-100SSB, delivers up to 380 mA at +12 V and -12 V as well as 100 mA at +5 V.

The A-100LC1v comes equipped with one 48 HP measuring row for 3U modules. Its power supply features eight connectors for oscillators, filters and so forth. The case is connected to the grid via an IEC power socket.

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

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

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

Notes: - High-grade patch cable designed for modular units
- 3.5mm mono jack plugs
- Length: 200cm
- Green finish

Notes: - High-grade patch cable designed for modular units
- 3.5mm mono jack plugs
- Length: 15cm
- Yellow finish

Notes: - High-grade patch cable designed for modular units
- 3.5mm mono jack plugs
- Length: 30cm
- Black finish

Notes: - High-grade patch cable designed for modular units
- 3.5mm mono jack plugs
- Length: 120cm
- Blue finish

Notes: - 6.3 mm jack male mono to 3.5 mm jack male mono
- Length: 1.5 metres

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

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: 50cm
- Angled connector on one end
- Orange finish

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: 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: Module A-105-2 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-130-4 contains four linear VCAs with a common level control section for all four VCAs. It can be used for all applications of simultaneous amplitude/level control of up to four different audio or CV signals. A-130-4 is the replacement of the no longer available module A-132-2. Compared to the A-132-2 the width has been reduced from 8HP to 4HP.

The module has these controls and in/outputs available:

Control Man.: manual control of the amplification
Control CV: attenuator for the control voltage applied to socket CVo socket Input 1
Sockets In 1...4: VCA inputs 1...4
Sockets Out 1...4: VCA outputs 1...4

Application examples:

simultaneous amplitude/level control of up to four different audio or CV signals
polyphonic application 1: simultaneous control of the frequency modulation depth of 4 VCOs (Quad-LFO A-145-4 or Quad-VCLFO A-147-5 > A-130-4 > FM inputs A-111-4)
polyphonic application 2: simultaneous control of the pulsewidth modulation depth of 4 VCOs (Quad-LFO A-145-4 or Quad-VCLFO A-147-5 > A-130-4 > PWM inputs A-111-4)
simultaneous control of quadrophonic signals

Technical notes:

The maximum amplification for each VCA is about 1 ("Man." control fully CW). Even with an external control voltage applied to the CV input the maximum amplification is limited to 1.
The module is equipped with two internal connectors (pin headers with 4 pins each). Pin header #1 can be used to normalize the four inputs to other modules (e.g. Quad LFO A-145-4 or A-147-5, Quad ADSR A-143-2). Pin header #2 can be used to connect the four outputs to other modules.
The max. level at the VCA inputs without clipping/distortion is about 20Vpp or +/-10V.

Dimensions
4 HP
45 mm deep

Notes: Module A-147-5 contains four voltage controlled low frequency oscillators (VCLFO) with triangle waveform outputs. All LFOs share a common frequency control. Each of the LFOs 2, 3 features a Delta control which is used to shift the frequency of the LFO in question up or down. With the Delta controls at center positions the frequencies of all LFOs are roughly the same. To control the frequencies by external control voltages four CV inputs are available which follow roughly the 1V/oct standard.

The module has these controls and in/outputs available:

Control F: manual control of the frequency for all four LFOs
Control Delta F2, F3 and F4: manual control of the frequency shift up/down for the LFO in question
Sockets CV 1...4: Frequency control voltage inputs (normalled from top to bottom)
Sockets with triangle symbol 1...4: triangle outputs
LEDs: visual displays of the triangle outputs (red = positive, yellow = negative output voltage)

Application examples:

Generation of four triangle modulation signals with a common frequency control for all LFOs and individual controls for the frequency deviation of each LFO, manually adjustable and controllable by external control voltages
Generation of modulation signals for polyphonic FM/PWM applications. For this the four CV inputs are connected to the same control voltages which are used to control the frequencies of the corresponding VCOs. That way each LFO follows the frequency of the associated VCO with the possibility to control the frequency of all VCOs (control F) and the frequency deviations (Delta F controls). For the simultaneous modulation depth control the Quad VCA module A-130-4 is recommended.
Generation of complex modulation signals by summing up the outputs (e.g. by means of a mixer module A-138n / A-138i / A-138j)

Technical notes:

The level of the triangle outputs is about +/-5V (10Vpp)
The manually adjustable frequency ranges from about 0.025 Hz (about 40 seconds) to about 50 Hz with the delta controls of LFOs 2, 3 and 4 about center position
The frequency deviations adjusted by the delta controls are about +/-1:5. Example: with 1 Hz in center position the frequency shift ranges from about 0.2 Hz in position -5 to about 5 Hz in position +5 (1 Hz/5 = 0.2 Hz, 1 Hz*5 = 5 Hz).
The manual frequency controls and the control voltage inputs have an exponential control behavior
With external control voltage the max. frequency is about 150 Hz, the minimum frequency
The scale of the CV inputs is roughly 1V/oct (not adjustable)
The CV inputs are normalled from top to bottom. Provided that only socket CV1 is patched CV1 controls the frequencies of all four LFOs.
When each CV input is patched to it's own control voltage each LFO is controlled individually by it's own CV. In this case CV1 controls only the frequency of LFO1.
Internally the rectangle outputs are available at four terminals (typ level +/-10V or 20Vpp). If required they can be wired to four sockets of a DIY breakout module made by the user, 1k protection resistors are recommended to avoid short circuits. If lower levels are required passive attenuators (voltage dividers) may be used.
Internally is even an (unbufferd) triangle sum signal available. For this each of the four triangle outputs is simply connected to the sum output terminal via a 47k resistor. This output has high impedance and should be buffered or amplified to avoid level drop when the load changes (e.g. by means of an A-180-3 or A-180-4 or A-183-3).
By changing the values of the capacitors in the LFO circuits even other frequency ranges are possible (e.g. Quad VCO to form kind of a cloud VCO). Pay attention that the accuracy of the CV input scales is not sufficient for precise 1V/oct VCO applications. The 1V/Oct scales cannot be adjusted and the circuits are not temperature compensated.

Dimensions
4 HP
45 mm deep

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: ***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-147-4V is a dual voltage controlled LFO (Low Frequency Oscillator). Each LFO has the five waveforms triangle, sine, rising and falling sawtooth, as well as rectangle available. The rectangle output features manually adjustable pulsewidth and pulsewidth modulation by means of an external control voltage. The core waveform is triangle. The other waveforms are derived from triangle by means of waveform converters. The frequency of each LFO can be adjusted manually and modulated by means of an external control voltage with associated attenuator and polarity switch. By means of a jumper the basic frequency range of each LFO can selected: about 0.02 Hz (~ 50 seconds) ... 2.5kHz or about 0.0017 Hz(~ 600 seconds) ... 220Hz. That way each LFO can be used also as a VCO with a max. frequency of about 2.5kHz. Each LFO features a reset input which can be used to reset the triangle signal.

The module has these controls and in/outputs available:

Control F : manual control of the frequency, for each LFO the frequency range can be selected by means of a jumper from two values (see technical notes)
frequency coverage of control F in the high frequency range: about 0.075 Hz (~ 13 seconds) ... 1,4kHz
frequency coverage of control F in the low frequency range: about 0.007 Hz (~ 140 seconds) ... 125Hz
Control CV: attenuator for the signal applied to the CV socket, by means of a jumper a small positive voltage can be applied to the switching contact of the /CV/ socket, as long as no patch cable is connected to /CV/ socket the CV control then works as fine control for the frequency
Switch CV Pol.: polarity switch for the signal applied to the socket /CV/
Control PW/PM: combined control for manual and CV control of the rectangle pulsewidth:
when no patch cable is connected to socket /P/ the control is used to adjust the pulsewidth (PW) manually
when a patch cable is connected to socket /P/ the control works as attenuator for the external CV signal with a basic pulsewidth of 50:50.
Socket /CV/: frequency control voltage input, in the factory the module is adjusted so that the sensitivity of this input is exactly 1V/octave when the CV control is fully CW.
Socket /R/: reset input, according to the associated jumper the reset input is edge triggered or level controlled (see technical notes for details)
Socket /P/: pulsewidth control voltage input
Sockets with waveform symbol: output of the waveform in question (triangle, sine, rising and falling sawtooth, rectangle)
The output voltage ranges are about -5V ... +5V (10Vpp), except the rectangle output
For the rectangle output one can choose by means of a jumper if the range is about -5V ... +5V or 0...+10V.
LED: visual control of the LFO (triangle)
The inputs of the module are labelled with white characters on black background (in the text included into two slashes). The outputs are labelled with black characters.

Technical notes and special features:

The basic frequency range of each LFO can be selected by means of a jumper. The settings correspond to two different capacitor values for the VCO circuit. The relation between the two ranges is about 1:11. When the upper range is selected frequencies from about 0.02 Hz up to 2.5kHz can be generated. For the lower range the values are about 0.0017 Hz ... 220Hz. To obtain these full frequency ranges external control voltages are required. With the frequency control F only the frequencies mentioned above are possible.

Apart from that the range for the manual control F can be reduced to obtain a finer resolution. For this a jumper has to be removed. The range of control F is then reduced to about 1:4.5 only.

In the factory the starting voltage of the triangle output after a reset is adjusted to 0V, i.e. the triangle starts from 0V with the rising slope after a reset. By means of a trimming potentiometer the starting voltage can be adjusted to another value (e.g. to -5V).

Another jumper is used to set the reset behaviour to edge triggered or level controlled. When set to edge triggered the rising edge of reset signal is used for the reset (independent of the duration of the "high" state of the reset signal). When set to level controlled the triangle output remains at the starting voltage as long as the reset signal is "high". Only when the reset signal turns "low" the triangle starts.

Power consumption: 80mA at +12 V and 70mA at -12 V
Depth: 45mm
HP : 8

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: Module A-147-4 is a dual voltage controlled LFO (Low Frequency Oscillator). Each LFO has the five waveforms triangle, sine, rising and falling sawtooth, as well as rectangle available. The rectangle output features manually adjustable pulsewidth and pulsewidth modulation by means of an external control voltage. The core waveform is triangle. The other waveforms are derived from triangle by means of waveform converters. The frequency of each LFO can be adjusted manually and modulated by means of an external control voltage with associated attenuator and polarity switch. By means of a jumper the basic frequency range of each LFO can selected: about 0.02 Hz (~ 50 seconds) ... 2.5kHz or about 0.0017 Hz(~ 600 seconds) ... 220Hz. That way each LFO can be used also as a VCO with a max. frequency of about 2.5kHz. Each LFO features a reset input which can be used to reset the triangle signal.

The module has these controls and in/outputs available:

Control F : manual control of the frequency, for each LFO the frequency range can be selected by means of a jumper from two values (see technical notes)

frequency coverage of control F in the high frequency range: about 0.075 Hz (~ 13 seconds) ... 1,4kHz

frequency coverage of control F in the low frequency range: about 0.007 Hz (~ 140 seconds) ... 125Hz

Control CV: attenuator for the signal applied to the CV socket, by means of a jumper a small positive voltage can be applied to the switching contact of the /CV/ socket, as long as no patch cable is connected to /CV/ socket the CV control then works as fine control for the frequency

Switch CV Pol.: polarity switch for the signal applied to the socket /CV/

Control PW/PM: combined control for manual and CV control of the rectangle pulsewidth:

when no patch cable is connected to socket /P/ the control is used to adjust the pulsewidth (PW) manually

when a patch cable is connected to socket /P/ the control works as attenuator for the external CV signal with a basic pulsewidth of 50:50.

Socket /CV/: frequency control voltage input, in the factory the module is adjusted so that the sensitivity of this input is exactly 1V/octave when the CV control is fully CW.

Socket /R/: reset input, according to the associated jumper the reset input is edge triggered or level controlled (see technical notes for details)

Socket /P/: pulsewidth control voltage input

Sockets with waveform symbol: output of the waveform in question (triangle, sine, rising and falling sawtooth, rectangle)

The output voltage ranges are about -5V ... +5V (10Vpp), except the rectangle output

For the rectangle output one can choose by means of a jumper if the range is about -5V ... +5V or 0...+10V.

LED: visual control of the LFO (triangle)

The inputs of the module are labelled with white characters on black background (in the text included into two slashes). The outputs are labelled with black characters.
Technical notes and special features:

The basic frequency range of each LFO can be selected by means of a jumper. The settings correspond to two different capacitor values for the VCO circuit. The relation between the two ranges is about 1:11. When the upper range is selected frequencies from about 0.02 Hz up to 2.5kHz can be generated. For the lower range the values are about 0.0017 Hz ... 220Hz. To obtain these full frequency ranges external control voltages are required. With the frequency control F only the frequencies mentioned above are possible.

Apart from that the range for the manual control F can be reduced to obtain a finer resolutuion. For this a jumper has to be removed. The range of control F is then reduced to about 1:4.5 only.

In the factory the starting voltage of the triangle output after a reset is adjusted to 0V, i.e. the triangle starts from 0V with the rising slope after a reset. By means of a trimming potentiometer the starting voltage can be adjusted to another value (e.g. to -5V).

Another jumper is used to set the reset behaviour to edge triggered or level controlled. When set to edge triggered the rising edge of reset signal is used for the reset (independent of the duration of the "high" state of the reset signal). When set to level controlled the triangle output remains at the starting voltage as long as the reset signal is "high". Only when the reset signal turns "low" the triangle starts.

Dimensions
8 HP
45 mm deep

Current Draw
80 mA +12V
70 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-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-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

Depth: 45mm
HP : 12

Notes: Module A-149-4 generates four triggered random voltages which meet the criteria choosen by several controls.

Manual controls for the criteria selection:

Octave range (manual control "Oct."): this parameter defines how many octaves are covered by the random voltages (0 ... +5V, with "Oct." control fully CCW only 0V are generated)

Grid (6 illuminated radio buttons): this parameter defines the grid of the random voltages:

Octaves (Oct)

Octaves + Quin (Quint)

Chords

Scale

Semitones

continuous (i.e. stepless)

Minor / Major (2 illuminated radio buttons): this parameter defines in case of chords or scales if they are minor or major. For all other grids this parameter has no meaning

Sixth / Seventh (2 illuminated separate buttons): these parameters defines if the sixth or seventh is added. Valid only if Oct, Quint, Chord or Scale is chosen as grid.

The output voltages follow the 1V/octave standard with exception of the Continuous mode. The voltages in this mode are totally random and do not follow the 1V/oct standard (i.e. not a multiple of 1/12V).
The generation of a new random voltage at the output (CV Out 1...4) is triggered by the corresponding trigger input (Trig. In 1...4). The trigger inputs are normalled top down. The minimum trigger level is +2.5V (up to max. +12V).

Applications:

random polyphonic structures (in combination with the polyphonic modules A-111-4, A-105-4, A-132-8, A-141-4 and e.g. A-157 as trigger source and A-173-1/2 for transposition of the polyphonic structures)

any application that requires several random voltages

Width: 4 HP / 20.0 mm
Depth: 45mm (measured from the rear side of the front panel)

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: 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: Theremin module for generating a variable control voltage by approaching/removing hand to/from an antenna.

The distance range is about 30 cm. Additionally the module is equipped with a Gate output with adjustable threshold level. To simulate the original Theremin two A-178, a VCO (e.g. A-110) and a linear VCA (e.g. A-130 or A-132) are required. But of course the A-178 can be used to control other functions in the A-100 (e.g. filter frequency, modulation depth and/or speed, tempo, attack/decay time and so on).

The CV output voltage of the A-178 can range - according to the setting of the front panel controls - from -10V...+10V.

The gate output switches from 0V to about +10V.

Power consumption: 60mA at +12V and 20mA at -12V

Depth: 40mm

HP : 8

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: 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: '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: 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-118-2 generates the signals white noise, colored noise, continuous random voltage and stepped random voltage.

The noise signal is generated 100% analog by amplification of the noise of a transistor. White and colored noise are usually used as audio sources. The random voltages are normally used as control voltages (e.g. for filter frequency or any other voltage controlled parameter).

The A-118-2 gives you the ability to mix the relative amounts of Red and Blue noise (low/high frequency component) in the colored noise output.

For the continuous random voltage the rate of change (Rate) and amplitude (Level) of the random voltage can be adjusted. The continuous random voltage is used as source for the S&H/T&H unit. The type of operation can be set to S&H (sample and hold) or T&H (track and hold). When T&H is chosen the output signal follows the input signal as long as the Clock input is "high". As soon as the clock signal changes to "low" the last voltage is stored. When S&H is chosen the input signal is sampled at the rising edge of the Clock signal. For the Clock signal a "digital" signal (e.g. Clock, Gate, rectangle output of an LFO) is required. Dual color LEDs are used to indicates the continuous and stepped random voltages.

Controls:
Blue: share of the high frequencies in the the colored noise output
Red: share of the low frequencies in the the colored noise output
Rate: rate of change of the continuous random voltage
Level: amplitude of the continuous random voltage
TH/SH: switches between T&H und S&H

Inputs and outputs:
RND: continuous random voltage output (with LED display)
TH/SH: stepped random voltage output (with LED display)
Clk: Clock input of the S&H/T&H unit
C Noise: colored noise output
W Noise: white noise output

Important notes:
After power on it takes a few minutes until the two noise signals and the random signals are generated. The module is not faulty when after power on the signals do not appear immediately!

The S&H/T&H function is realized by pure analog circuitry (electronic switch followed by a holding capacitor and buffer). Consequently the output voltage drifts a bit in the holding state because the capacitor is discharged by parasitic resistors. The drift depends also upon environmental conditions like humidity or temperature.

The level of the random voltage changes with the settings of the Blue and Red controls. Especially the Red control affects the random voltage level (which is derived by low pass filtering from the colored noise signal) because the Red control changes the share of the low frequencies in the colored noise signal. The effect of the Blue control is much smaller because it changes the share of the high frequencies in the colored noise signal which are filtered out by the low pass of the random circuitry.

Power consumption: 20mA at +12V and 20mA at -12V
Depth: 40mm
HP : 4