Suchergebnisse: Dance Music

Notes: Module A-110-2 is a low-cost voltage-controlled oscillator. It's a slightly reduced version of the standard VCO A-110-1. Compared to the A-110-1, the A-110-2 has no sine output and the (expensive) octave rotary switch is replaced by a 3-position toggle switch. In return, the A-110-2 is equipped with an additional linear FM input and a soft sync input. A jumper is used to select the range of the tune control between about 1/2 octave and about 4 octaves. The width of the module is only 8 HP compared to the 10 HP of the A-110-1.

All other features are essentially the same as for the A-110-1.

Explanation of the jumpers and trimming potentiometers:

- JP2: CV connection to A-100 bus
- JP3: range of Tune control (installed = about 4 octaves, not installed = about 1/2 octave)
- JP4: AC/DC coupling of the linear FM input (installed = DC coupling, not installed = AC coupling)
- P5: 1V/Oct scale
- P6: frequency offset
- P7: high-end trim
- P8: adjustment +1 Oct. range switch
- P9: adjustment -1 Oct. range switch
- P10: temperature VCO heater

The core of the A-110-2 is - like the A-110-1 - a sawtooth oscillator (in contrast to the A-111-1, which is based on a triangle oscillator). The other waveforms are derived from the sawtooth by waveform converters. As the sawtooth reset (i.e. the back-to-zero slope) is not infinitely fast but takes a little bit of time the triangle is not perfect! At the bottom of the waveform it has a small glitch or notch that is caused by the sawtooth reset and cannot be eliminated by the waveform converter. If a perfect triangle is required, the A-111-1 is recommended.

The sawtooth output of the A-110-21 has a falling (or negative) slope. The front panel shows erroneously a rising (or positive) slope. This has no influence on the sound but becomes important when the module is used as an LFO or is mixed with the sawtooth output of another VCO.

The control voltage applied to the socket 1V/Oct is added to the control voltage coming from the bus (interruptible by removing the jumper JP2). Connecting a cable to the socket 1V/Oct does not interrupt the bus CV connection!

Notes: This analogue VCO is well versed in the art of deep and beautiful thru-zero frequency modulation, allowing the frequency to stop when CVs with 0V are applied, and even to go backwards when modulated with negative CVs.

The term "quadrature" refers to simultaneously available sine and cosine waves at individual outputs. The VCO is sine based i.e. no waveshaping is used to derive the sine; for that reason, the sound is really clear and shows a minimum of distortion and overtones.

The module has two control sections:

The exponential section consists of the XTune control, the 1V/Oct input and the XFM input with the corresponding attenuator XFM.

The exponential control voltage is the sum of these three voltages. The linear section consists of the LTune control and the LFM input with the corresponding attenuator LFM. The linear control voltage is the sum of these two voltages.

The main advantage of the A-110-4 compared to other Thru Zero VCOs is that the design uses a sine/cosine core. The sine/cosine waves are not derived from other waveforms (e.g. sawtooth or triangle) by means of waveshaping. Rather the sine and cosine waves are the core of the VCO which results in very pure waves with a minimum of distortion and overtones.

With it's both control possibilities, linear and exponential, as well as it's thru-zero ability, the VCO is perfectly suited for all types of FM applications.

Notes: The Micro Precision VCO is a space-saving and utterly precise analog VCO/LFO with a extremely wide frequency range, immaculate tracking over at least ten octaves and nearly perfect waveforms.

Basically, it's the same circuitry like the High-End VCO A-111-2 but with reduced functions and controls. It is suitable as a modulator for exact linear FM and much more.

The A-111-3 has two elements for setting the frequency: A switch selecting between LFO and VCO mode as well as a tune control with a jumper-selectable range:

- Jumper position 1: 16Hz to 20 kHz
- Jumper position 2: 16Hz to 70Hz
- Without jumper: 16Hz to 22Hz

The XM potentiometer can be used as a fine tune control as long as nothing is patched to the XM socket.

The oscillator has a frequency range of at least fifteen osctaves (0.0001 - 40 Hz in LFO mode; 0.5 Hz to 20 kHz in VCO mode) and offers perfect 1 V per octave tracking over ten octaves minimum, typically in the range of 20 Hz to 20 kHz. Frequencies below 25 Hz are visualized with a two-colour LED.

The 1V per octave input is accompanied by two FM inputs, one for linear and one for exponential frequency modulation. A jumper determines whether the module obtains pitch CV via the internal bus.

The VCO has a triangle core from which sawtooth, pulse and triangle are derived. The wave forms are almost perfect and sans glitches.

The pulse width can be set with a control from 0 to 100% and of course it can be modulated.

There is one input for oscillator synchronisation and its type, either hard or soft sync, is jumper-selected. Both types differ in sound with the hard sync being more aggressive and richer in harmonics.

Notes: The successor of the good old A-111 High End oscillator is an utterly precise analogue VCO/LFO with an extremely big frequency range, immaculate tracking over at least ten octaves and nearly perfect waveforms. With linear and exponential FM, pulse width modulation, two simultaneous types of sync and attenuators on all CV inputs, the module is really well-appointed.

Not less than four frequency controls make tuning an ease:

- Switch for LFO or VCO range
- Octave rotary switch with six positions
- Fine tuning control (approximately one octave range)
- Coarse tune control (approximately one semitone range)

The oscillator has a frequency range of at least fifteen octaves (0.0001 - 40Hz in LFO mode, 0.5Hz - 20kHz in VCO mode) and has perfect Volt per octave tracking over at least ten octaves, typically in the range of 20Hz to 20kHz. Frequencies below 25Hz are visualized with a two-colour LED.

An 1V/octave input without attenuator is expanded by two scaleable FM inputs, one for linear and one for exponential frequency modulation. Using a jumper, you can decide whether the module obtains pitch CV via the internal bus.

The VCO has a triangle core from which sawtooth, pulse and sine are derived. The wave forms are almost perfect and sans glitches.

The pulse width can be set with a control from 0 to 100% and of course it can be modulated.

The A-111-2 features not only one but two inputs for oscillator synchronisation - one for hard and one for soft sync, which both differ in sound with the hard sync being more aggressive and richer in harmonics.

Notes: The successor of the good old A-111 High End oscillator is an utterly precise analogue VCO/LFO with an extremely big frequency range, immaculate tracking over at least ten octaves and nearly perfect waveforms. With linear and exponential FM, pulse width modulation, two simultaneous types of sync and attenuators on all CV inputs, the module is really well-appointed.

Here are the most important features of the module:

triangle core (i.e. all other waveforms are derived from the triangle by waveshapers)
fully analog design
min. 15 octaves pitch range (typ. 0.5Hz - 20kHz in VCO mode / 0.001Hz - 40Hz in LFO mode)
perfect 1V/octave tracking over min. 10 octaves, typ. 20Hz - 20kHz (control LF has to be fully CW for perfect 1V/octave tracking)
exponential frequency controls and inputs:
Tune: range can be selected by means of a jumper, about +/- 1 octave (jumper JP6 not installed) or about +/- 3 octaves (jumper JP6 installed)
Fine: about +/- 1 semitone range
Octave: range switch with 6 positions for 6 octaves
1V/octave CV input
XFM input with attenuator
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)
linear frequency controls and inputs:
LF (manual linear frequency control: fully CW = standard setting for usual VCO applications, fully CCW: close to 0Hz frequency) works also as a kind of range control for the exponential section but for standard VCO applications with 1V/octave control voltage the LF control should be fully CW !
LFM input with attenuator, DC coupled
Pulsewidth controls and inputs (for rectangle output):
PW (manual pulsewidth control from 0%/output = fixed at "low" state up to 100% / output fixed at "high" state)
PWM input with attenuator
Hard Sync input (CEM3340 hard sync type)
Soft Sync input
Waveform outputs:
Sawtooth, output level ~ 10Vpp (voltage range ~ 0 ... +10V)
Rectangle (controlled from pulsewidth section), output level ~ 10Vpp (voltage range ~ 0 ... +10V)
Triangle (output level ~ 10Vpp, voltage range ~ -5V ... +5V)
Sine (output level ~ 10Vpp, voltage range ~ -5V ... +5V)
Range switch to select VCO/VCLFO mode, frequency relation between VCO mode and LFO mode about 500 : 1
dual color LED display (to display low frequencies below ~ 25 Hz)
Nearly "perfect" waveforms
high end triangle to sine converter with excellent sine waveshape (thank's to Tim Stinchcombe who recommended this circuit)
the micro precision VCO A-111-3 uses the same VCO core as the A-111-2, but has less inputs, outputs and controls

Notes: Module A-199 is a spring reverb module. The reverb effect is electronically simulated by means of 3 spiral springs. Spring reverb systems have a very characteristic sound that is based on the (insufficient) mechanical properties of the springs like signal delays, audio resonances, limited frequency range, acoustic feedback behaviour, sensitivity to mechanical shocks and others.

The 3-spring system used in the A-199 ensures a "dense" reverb because of the different properties of the three springs.

The A-199 implies some special features that are not self-evident for spring reverb units:

The reverb signal can be fed back to the input using the Feedback control. Even self-oscillation of the springs similar to the self-oscillation of filters is available. The feedback loop can lead even via external modules like VCA, VCF, phaser, frequency shifter, vocoder, distortion/waveshaper, ring modulator and others. In this case the reverb output of the A-199 is connected to the input of the external module(s) and the output of the external module(s) is fed back to the Ext. Feedback In socket of the A-199. This socket contains a switch that interrupts the internal feedback loop as soon as a plug is inserted.

Another feature is the Emphasis control. This enables the adjustment of the accentuation of middle frequencies (around ~ 2kHz).

With the Mix control the relation between original and reverb signal appearing at the mix output is adjusted.

Using all these features very extreme and unusual effects can be generated with the A-199.

Notes: Module A-113 is a new sound source that derives four so-called subharmonics (German: Subharmonische) from an incoming pulse signal. The term subharmonics was introduced by Oskar Sala in connection with his so-called Mixtur-Trautonium. A subharmonic means in this context a sawtooth wave (German: Kippschwinger) whose frequency is derived from a master frequency and the master frequency is an integer multiple in the range of 1...24 of the subharmonic - in other words: the master frequency is divided by an integer 1...24 to obtain the subharmonic.

The output waveform of a subharmonic is sawtooth (as also used in the original Trautonium) and not sine. The term subharmonics is somewhat misleading. The master frequency comes e.g. from an A-110 or A-111 to the frequency input of the A-113. The frequency dividers of the 4 subharmonics is adjusted with up/down buttons as displayed with two character LED displays. The subharmonics are available as single outputs and as mix output with adjustable levels for the subharmonics.

Two gate type control inputs enable to select between 4 different mixtures, i.e. 4 different settings of the frequency dividers. In the original Trautonium these are controlled by foot switches to switch between 3 mixtures while playing (the original Trautonium has only 3 mixtures available but with the 2 gate inputs of the A-113 four different settings can be addressed).

Additionally, the A-113 features a mixture memory with 50 presets. Each preset consists of 4 mixtures that can be selected with the gate inputs, each mixture contains the values of the 4 frequency dividers.

Notes: Module A-114 contains two separate ring modulators. A ring modulator outputs the product (Multiplication X - Y) of the signals at inputs X and Y. It's similar to a VCA, but whereas a VCA only responds to positive voltages at the inputs (2-quadrant multiplication), the ring modulator responds to both positive and negative voltages (4-quadrant multiplication).

The ring modulator thus provides a refinement of amplitude modulation (AM). Ordinary amplitude modulation will output the original carrier frequency fC as well as the two side bands (fC - fM, fC + fM) for each of the spectral components of the carrier and modulation signals - but ring modulation cancels out the carrier frequencies, and just lets the side-bands pass to the output (see Fig. 1).

A ring modulator is used for the production of bell-like sounds, alien voices, or just to produce new timbres.

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-116 provides voltage-controlled dynamic waveform modification of audio signals. It can produce new waveforms from the standard VCO shapes, and modulate these changes in real time. The signal first of all goes through an input amplifier, which can attenuate the signal as well as amplify it by up to a factor of 2.

After the input amplifier, the signal goes through two parallel processors: a clipping circuit, and an asymmetrical amplifier. The processed signals are added together and sent to the output.

Clipping-Level and Symmetry amounts are not just manually controllable, but can also be modulated by control voltages, to produce complex, constantly changing waveforms.

Notes: Module A-117 (DNG) is a combination module, including a digital noise generator and an 808 source.

The digital noise generator uses random sequences of square waves (18 step shift register with multiple feedback), whose rate can go from random clicks to noise. The colour of the noise is very different from the analogue noise produced by the A-118. The frequency range of the internal clock oscillator is about 100Hz - 100kHz.

In addition to a manual setting, the rate can be controlled by an external clock - eg. VCO, high speed VCO of A-188-1/2, LFO or MIDI clock.

The 808 Source aims to re-create the sort of multi-oscillator array that was used in Roland's TR-808 and 606 drum machines as the basis of the sound of the hi-hat, cymbals and cowbell. The cowbell mix uses two oscillators, and the cymbals mix six.

Notes: Module A-118 is a noise and random voltage generator. It produces three types of signal: white noise, coloured noise, and random voltage.

White and coloured noise can be used as audio sources, and also, in conjunction with a sample & hold module, as control voltages, and the random voltage is a useful source of voltage control, especially for its low frequency content.

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

There are knobs to control the rate of change and amplitude of the random voltage, and two LEDs indicate the state of the voltage at any one time.

Notes: Module A-114 contains two separate ring modulators. A ring modulator outputs the product (Multiplication X - Y) of the signals at inputs X and Y. It's similar to a VCA, but whereas a VCA only responds to positive voltages at the inputs (2-quadrant multiplication), the ring modulator responds to both positive and negative voltages (4-quadrant multiplication).

The ring modulator thus provides a refinement of amplitude modulation (AM). Ordinary amplitude modulation will output the original carrier frequency fC as well as the two side bands (fC - fM, fC + fM) for each of the spectral components of the carrier and modulation signals - but ring modulation cancels out the carrier frequencies, and just lets the side-bands pass to the output (see Fig. 1).

A ring modulator is used for the production of bell-like sounds, alien voices, or just to produce new timbres.

Notes: Blank panel, 2HP, constructed from anodised aluminium, black.

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

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: Module A-118-2 is the slim version of module A-118-1 and offers essentially the same features as the A-118-1. 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-118-1. The module is primarily planned for applications where only limited space is available. The functional difference between A-118-1 and A-118-2 is the additional T&H/S&H unit which is not included in the A-118-1.

The module generates the signals white noise, colored noise, continuous random voltage and stepped random voltage (derived from the continuous random voltage by means of a S&H/T&H unit).

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 (low frequency component) and Blue noise (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 derived from the colored noise signal by low pass filtering. Consequently the settings of the controls for the colored noise (Blue, Red) affect the behavior of the random voltage! A dual color LED (red = positive / yellow = negative output voltage) indicates the continuous random voltage.

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 (= continuous random voltage) 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 (= continuous random voltage) 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. It does not work with slowly changing continuous CV signals. Another dual color LED (red = positive / yellow = negative output voltage) indicates the stepped random voltage.

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 and 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.

Dimensions
4 HP
40 mm deep

Current Draw
20 mA +12V
20 mA -12V

Notes: Module A-121-3 is functionally nearly identical to module A-121-2. Only the distances between the controls and sockets are smaller and rubberized, small rotary knobs are used. Therefore the front panel width is only 4HP compared to 8HP of the A-121-2. In the first place it is planned for applications where only limited space is available. The only functional difference compared to the A-121-2 is the missing attenuator for the resonance CV input CQ.

These are the most important features of the module:

- Voltage-controlled multi-mode filter with a cut-off slope of -12 dB / octave (identical to the filter of the Dark Energy II/III but has been expanded by the voltage controlled resonance feature)
- Four simultaneous outputs are available, each with different characteristics: low-pass (LP), high-pass (HP), band-pass (BP) and notch (N)
- Manual control Frequ. for the cut-off frequency of the filter (the cut-off frequency determines the point at which the respective filter effect appears)
- Two inputs for frequency control by means of external control voltages (frequency modulation, e.g. by ADSR or LFO):
- Control voltage input CV1 without attenuator, about 1V/octave sensitivity
- Control voltage input CV2 with attenuator FCV2 for the adjustment of the modulation depth of input CV2
- Frequency range about 10Hz ... 20kHz
- Manual control Q for the resonance of the filter
- Control voltage input CQ without attenuator for voltage control of the resonance
- Resonance up to self-oscillation, in which case the module will behave like a sine wave oscillator even without audio input signal
- Audio input In with attenuator Level for the adjustment of the filter input level (beyond about pos. 5 clipping/distortion occurs with typical A-100 audio levels)

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-138i is a four channel mixer with an additional mute switch for each input. On top of that it is equipped with two types of single outputs and a dual mix output. All inputs and outputs are DC coupled. Consequently the VCAs can be used to mix both audio and control voltages.

Each input is - apart from the mute switch - equipped with the usual attenuator.

The single outputs offer the attenuated and possibly muted signal of the channel in question. Two version of single outputs are available:

Single Output A: If a plug is inserted into the single output "A" socket the channel in question is removed from the sum signal.

Single Output B: If a plug is inserted into the single output "B" socket the channel in question is not removed from the sum signal. This type of single outputs is available only for the channels 1 and 2.

The output is twice available (two sockets, hard-wired like a multiple).

The distances between the controls and sockets are smaller as for the standard A-100 modules and rubberized small-sized knobs are used. In return the front panel has 6 HP width only. The module is primarily planned for applications where only limited space is available.

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-111-4 contains four precision VCOs and has individual controls, inputs and outputs for each VCO available as well as a common control and output unit. After all the A-111-4 is very similar to four A-111-3 without LFO mode but built in output mixers for the three waveforms, and a master unit for all four VCOs.

Controls, inputs and outputs for each of the four VCOs:

- 1V/Octave CV input
- Octave switch (+1 / 0 / -1 octave)
- Tune control (range internally adjustable by jumpers: ~ 2 semitones / ~ 1 octave / ~ 4 octaves)
- Modulation CV input
- Modulation destination: Upper position: exponential frequency modulation (XM) / Lower position: linear frequency modulation (LM) or pulsewidth modulation of the rectangle (PM), selectable via internal jumper
- Frequency Modulation (FM) or Pulsewidth Modulation of the rectangle (PWM)
- Modulation intensity
- Triangle output
- Sawtooth output
- Rectangle output (about 50% without external PWM)
- Sync input (hard or soft sync internally selectable via jumper, CEM3340 hard sync type)
- CEM3340 based VCO (triangle core)
- Each VCO has it's own separate internal +/- power supply for each for best stability and the prevention of unwanted synchronisation of the VCOs

Controls, inputs and outputs of the master section:

- 1V/Octave CV input
- Octave switch (+1 / 0 / -1 octave)
- Tune control (range internally adjustable by jumpers: 2 semitones / 1 octave / 4 octaves)
- Frequency Modulation CV input (FM)
- FM intensity
- Triangle sum output
- Sawtooth sum output
- Rectangle sum output
- As soon as the single waveform output of a VCO is patched this waveform of the VCO in question is removed from the sum (this function can be turned off for each single output socket by means of solder bridges on the pc board, i.e. the sum contains then all signals independent of the patching of the single output)
- CV output (outputs the sum CV that is used to control all four VCOs)
- 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)

Typical applications:

- Fat sounding monophonic VCO with the possibility to adjust any intervals
- Paraphonic patches in combination with the polyphonic CV interface A-190-5 (all four VCOs processed by one VCF/VCA)
- Full polyphonic patches in combination with the polyphonic CV interface A-190-5 and four complete VCF/VCA sections
- Complex VCO patches with up to four VCOs by means of the frequency modulation features (exponential an linear) and the sync functions

Notes: Module A-145 is a low frequency oscillator, which produces cyclical control voltages in a very wide range of frequencies. Five waveforms are available: sawtooth, inverted sawtooth, triangle, sine and square wave.

The LFO can be used as a modulation source for any number of modules - for instance modulating the pulse width or frequency of a VCO, modulation of the cut-off frequency of a VCF, or amplitude modulation with a VCA.

A three-way switch lets you select three frequency ranges, spanning from one cycle every several minutes at the lowest, to moderate audio frequency at the highest (about 4-5 kHz).

The LFO signal can also be synchronised, via the reset input.

Notes: Module A-138 is a four channel mixer, which can be used with either control voltages or audio signals. Each of the four inputs has an attenuator, and there's a master attenuator, so that the mixer can be used at the end of the audio chain - i.e. it can be used to interface directly with an external mixer, amplifier, etc.

The A-138a version features potentiometers with linear response, so especially suitable for control voltage mixing.

Notes: 2HP narrow version of the A-180 multiples module. It is a passive signal splitter suitable for audio or CVs. Two sets of four jacks are interconnected, by placing a solder bridge you can connect all eight jacks.

Dimensions
2 HP
18 mm deep

Current Draw
Module does not draw current

Notes: The A-139-2 is a headphone amplifier module with two mono inputs and a stereo headphone output. It can be used for driving small loudspeakers, LED strips, small magnets etc.

- Two-channel headphone amplifier
- Two audio inputs with level controls
- Input 1 is normalled to Input 2
- Common loudness/master level control
- Headphone output (stereo 1/4" jack socket)
- Max. output power ~ 2 W per channel (@ 8 Ohm load)
- DC coupled inputs and outputs (i.e. also useful for other applications like small loudspeakers, lamps, LEDs, magnets, motors - provided that the power is sufficient)

Notes: Module A-140-1 is an envelope generator, and, since it puts out control voltages, counts as one of the modulation devices in a modular system. As soon as the gate input receives sufficient voltage, the ADSR generates a variable voltage, changing in time, called an envelope. This varying voltage is output in normal (positive) and inverted form, and can be used, eg. for voltage controlled modulation of a VCO, VCF, or VCA, or for processing other modules' inputs and outputs.

The shape of the envelope is governed by four parameters: Attack, Decay, Sustain and Release.

The envelope is started (triggered) by a gate signal either from the INT.GATE voltage on the system bus, or, if a signal is put into it, from the gate input socket.

The envelope can also be re-triggered, i.e. start from scratch again, each time a trigger signal is sensed at the Retrig. input socket, when the gate is still open.

Module A-140 has available a three-position toggle switch to select one of three time ranges. The time ratios for the three ranges are about 1 : 20 : 1000. The absolute Attack times are about:

20uS ... 100ms (switch position L)
400uS ... 2s (switch position M)
20ms ... 120s (switch position H)
The Decay and Release times are about 3-4 times more. Because of the exponential slope and the gradual asymptotic approach to the zero level the exact specification of the decay and real times is a bit difficult.

The voltage ranges of the ADSR outputs are about 0 ... +8V for the two normal outputs and 0 ... -8V for the inverted output.

In combination with the Comparator module A-167 a free-running "ADSR-LFO" can be realized.

Notes: The A-141-2 module is an ADSR envelope generator with voltage controlled attack, decay, sustain and release parameters. Other features include LFO functionality as well as digital end-of-attack and end-of-release outputs. Besides positive and inverted outputs there is an output with voltage controlled amplitude available.

Attack, Decay, Sustain and Release parameters of the A-141-2 can be adjusted manually as well as via control voltages. The CV inputs come equipped with attenuators. In addition, a Comm-CV socket was implemented. Control voltages fed to this input influence all time parameters (A, D and R) simultaneously. Thus, it is possible to make high pitched notes shorter and more percussive. - Just like the behaviour of many acoustic instruments. The time range of the envelope goes from 50 microseconds to six seconds. Using a toggle switch, it is possible to increase these values by a factor of ten (500 us to 60 s) or a factor of hundred (5 ms to 10 min). To activate the envelope, there are gate and retrigger inputs.

The A-141-2 is equipped with a normal and an inverted output. Both connectors work with a fixed level. Furthermore, there is a third, variable output. Here, before reaching the out socket, the envelope signal is fed to a voltage controlled VCA. - Perfect for velocity CV signals. A jumper on the circuit board allows you to choose between a unipolar and a bipolar mode of operation. Other jumpers make it possible to normalize the CV inputs.

Last but not least, there are two digital outputs called EOA and EOR, which emit a gate signal after the attack respectively release phase. This is useful for delayed triggering of other envelopes. By connecting EOA or EOR output to the gate input, you can make the A-141-2 oscillate like a LFO. Adjustments to the envelope times change the frequency and waveform. If you connect the Attack CV input to the inverted output or the Decay respectively Release CV input to the normal output, you can alter the curve characteristics.

Notes: The A-141-2 module is an ADSR envelope generator with voltage controlled attack, decay, sustain and release parameters. Other features include LFO functionality as well as digital end-of-attack and end-of-release outputs. Besides positive and inverted outputs there is an output with voltage controlled amplitude available.

Attack, Decay, Sustain and Release parameters of the A-141-2 can be adjusted manually as well as via control voltages. The CV inputs come equipped with attenuators. In addition, a Comm-CV socket was implemented. Control voltages fed to this input influence all time parameters (A, D and R) simultaneously. Thus, it is possible to make high pitched notes shorter and more percussive. - Just like the behaviour of many acoustic instruments. The time range of the envelope goes from 50 microseconds to six seconds. Using a toggle switch, it is possible to increase these values by a factor of ten (500 us to 60 s) or a factor of hundred (5 ms to 10 min). To activate the envelope, there are gate and retrigger inputs.

The A-141-2 is equipped with a normal and an inverted output. Both connectors work with a fixed level. Furthermore, there is a third, variable output. Here, before reaching the out socket, the envelope signal is fed to a voltage controlled VCA. - Perfect for velocity CV signals. A jumper on the circuit board allows you to choose between a unipolar and a bipolar mode of operation. Other jumpers make it possible to normalize the CV inputs.

Last but not least, there are two digital outputs called EOA and EOR, which emit a gate signal after the attack respectively release phase. This is useful for delayed triggering of other envelopes. By connecting EOA or EOR output to the gate input, you can make the A-141-2 oscillate like a LFO. Adjustments to the envelope times change the frequency and waveform. If you connect the Attack CV input to the inverted output or the Decay respectively Release CV input to the normal output, you can alter the curve characteristics.

Notes: Module A-142-1 is a voltage controlled envelope generator. The only time parameter is decay (like TB303). Decay may be adjusted manually and via voltage control input (with attenuator). The envelope output is displayed with LED control. Additionally from the envelope signal a Gate signal and an inverse Gate signal with adjustable threshold is derived. LED control for Gate output. Thus one obtains a voltage controlled Gate additionally or alternatively to the envelope signal with voltage controlled duration.

The attack time is fixed to about 0.2 ms, the shortest decay time is about 2 ms. By changing the value of a capacitor the shortest time can be modified (details can be found here: A100_Capacitors.htm).

Typical applications: dynamic control of decay e.g. in combination with the Analog/Trigger Sequencer A-155, voltage controlled trigger delay functions (like A-162, but voltage controlled).

Notes: Module A-142-4 contains four simple envelope generators. The only time parameter is Decay and can be adjusted manually by means of the Dec. control in the range 2 ms ... 2 seconds. The attack time can be adjusted internally by means of a separate trimming potentiometer for each sub-unit in the range 1 ms ... 15 ms. The factory setting is about 3 ms. This is the attack time of the TB303. Each envelope output has a LED control available. The trigger inputs are normalled (1 -> 2 -> 3 -> 4).

Suggestions for modifications:

Each sub-unit has a pin header with two pins available. When the two pins are shortened (e.g. by means of a jumper or a toggle switch connected to the two pins) the corresponding sub-unit changes to a loop mode. In this mode the unit is triggered by itself like an LFO..

By changing the value of a capacitor the time range can be modified (e.g. 0.2 ms ... 0.2 seconds or 20 ms ... 20 seconds)

Notes: Module A-143-1 is a complex envelope generator that consists of Attack/Decay generators. For the complex envelope generator the four units are daisy-chained, i.e. the preceding unit triggers the following unit. The four units can be used even as four separate AD generators (switch position AD) or AD-type LFOs (switch position).

Details: Module A-143-1 contains four separate attack/decay type envelope generators. Each unit can be switched into a free running mode (LFO mode). The LFO mode differs in several points from a regular LFO (like A-145, A-146 or A-147): The slopes are exponential - in contrast to linear slopes of a normal LFO, and the frequency is defined by both controls. The attack control defines the time of the rising slope, the decay control the falling slope.

Each unit has available a comparator that compares the AD output voltage with a manually adjustable threshold and switches the corresponding comparator output (Cp 1...4) to "high" as soon as the AD output voltage goes in the decay phase below this value. The comparator output is normalled to the trigger input of the next stage via the switching contact of the trigger input socket. Consequently the first unit triggers the second, the second triggers the third and so on.

Each AD generator is equipped with a Polarizer (look at the Voltage Controlled Polarizer A-133 concerning details about the polarizer function) and a mixer that adds up all polarizer outputs. This allows to add up all AD/LFO output signals inverting or non-inverting with adjustable level to the mix output. Additionally a single output (Env 1...4) is available for each unit.

If the trigger input of unit 1 is controlled by a normal gate signal (e.g. from a keyboard resp. MIDI-to-CV/Gate interface) one obtains a very complex envelope signal at the mix output. The signal contains 8 segments controlled by Attack 1, Decay 1, Attack 2, Decay 2, Attack 3, Decay 3, Attack 4 and Decay 4. The transition between the stages (i.e. when the following AD generator is triggered) is controlled by threshold knob. The positive or negative contribution of each unit to the mix signal is adjusted with the Mixing Polarizer control. If the trigger input of unit 1 is controlled by the comparator output of unit 4 one obtains a 8 stage LFO.

The single AD outputs can be used to control VCAs or VCFs that open one after another corresponding to the AD signals (a little bit similar to the Shepard generator A-191).

The default-connection between the four units (CPn = Trig.n+1) can be interrupted by patching cables into the trigger inputs. Consequently the four units can be used as separate AD generators or LFOs. In any case the mix signal is available (e.g. mix of four AD generators or LFOs with adjustable level and sign).

In the LFO mode the comparator output serves as LFO rectangle output with adjustable pulse width (= threshold control).

Each unit is equipped with a separate LED display for envelop and comparator output. The shortest attack/decay time is about 5 ms, the longest attack/decay times are about 3 seconds (attack) / 10 seconds (decay). By changing the value of a capacitor the shortest time can be modified (details can be found here: A100_Capacitors.htm).

The sketch at the bottom of the page shows the module principle with 4 daisy-chained AD units (as predetermined by the normalled sockets), that are mixed with the integrated polarizing mixer.

Notes: Module A-143-3 is a low-cost four-fold modulation oscillator, often called LFO (low frequency oscillator). Like the other modules of the A-143 series (A-143-1 and A-143-2) not a very "exciting" module, just a bread-and-butter device and a simple demon for work. The module contains four simple LFOs. Each LFO is equipped with three waveform outputs: triangle, rectangle and rising sawtooth. The frequency of the sawtooth output is twice the frequency of the other outputs. A three-way switch is used to select one of three frequency ranges mid-low-high, spanning from about two cycles per minute at the lowest, to moderate audio frequency at the highest (about 5 kHz).

If other waveforms or additional LFO features are required (e.g. reset input, adjustable waveform, voltage controlled frequency) the LFO modules A-145, A-146 and A-147 are available.

Notes: Module A-143-4 is a fourfold voltage controlled low frequency oscillator (LFO). As the frequency range includes moderate audio frequencies it can be used as a four-fold VCO too.

- Four independent VCLFOs/VCOs with triangle core
- Frequency range switches: low (bottom position) = LFO mode, high (top position) = VCO mode
- Two frequency control CV inputs for each unit
- CV1 without attenuator (~ 1V/oct)
- CV2 with attenuator
- Manual frequency control
- Internal jumpers for the frequency range of the manual frequency controls:
- Jumper not installed: ~ +/- 1 octave range (mainly for VCO applications)
- Jumper installed: ~ +/- 5 octaves range (mainly for VCLFO applications)
- Sync inputs: Combined Reset/Direction inputs for unit #1 - #3 / Separate Reset and Direction inputs for unit #4 (normalled sockets, i.e. Reset is connected to Direction if the Direction socket is unused) / Up/both/down direction switch for unit #4, for technical details concerning the Reset and Direction function please refer to the sketch below
- Triangle and rectangle outputs for each unit
- Typ. output voltage range -5V ... +5V for both outputs (i.e. about 10 Vpp, symmetrical with reference to 0 V)
- Red/yellow LED displays for the triangle outputs (red = negative output voltage, yellow = positive output voltage)
- Common control section with two CV inputs and manual control (these inputs and controls affect the frequency of all four units)
- Sum outputs for triangle and rectangle with red/yellow LED displays
- Optional ultra-low frequency mode: for this a negative voltage can be applied via a jumper internally to the CV2 input of each unit and the common section (i.e. a negative voltage is normalled to the socket CV2 in question). Then the CV2 - - Attenuator control works as a negative frequency control (i.e. turning up this control lowers the frequency). Herewith LFO periods up to about one hour (or even more) are possible.
- Optional CV bus access via jumper (i.e. the module can pick up the CV from the A-100 bus, e.g. generated by a Midi/CV or USB/CV interface A-190-x or a bus access module A-185-1/2), if the jumper is installed the bus CV affects all four units as the bus CV is added to the CV generated by the common control section
- Typ. frequency range: < 0.001 Hz (~ one hour, LFO mode with ultra-low option) ... 15 kHz (VCO mode with installed frequency range jumpers for the manual frequency controls)
- Heat-up time: ~ 15 minutes (required to heat-up the main circuit by the affixed oven)

The module was planned mainly as a quad VCLFO. But we added a range switch (nothing but a switch for two different capacitors) so that even audio frequencies are possible and the module can be used as VCO with some restrictions too. Because of the closeness of the main circuitry (i.e. four VCO cores within less ~ 1 square millimetre) the oscillators may lock if the frequencies are very close to each other and the VCO frequencies interact marginally. If a high quality quad VCO is required the A-111-4 is recommended as this module has four separate VCO circuits available.

The reset circuitry is optimized for the LFO mode. As it takes some time to discharge the oscillator capacitor the discharge time had to be chosen so that the capacitor is fully discharged in LFO mode. In the high range (where a much smaller capacitor is used) this will cause a zero state duration in the 0.3 ms range if the oscillator is synced (during this time the capacitor is shortened for discharge).
The control scale of the inputs "CV1" is about 1V/octave. To improve the behaviour in the VCO mode a tempco circuit is used to keep the temperature of the exponential converter at a fixed temperature (similar to the tempco option of the DIY SYNTH). That way the frequency of the VCOs (and even the VCLFOs) is nearly independent from the environment temperature. But the accuracy (1V/octave scale and temperature compensation) is not as precise as for the dedicated VCOs A-110 and A-111-1.

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-146 (LFO 2) is a Low Frequency Oscillator, which produces periodic control voltages over a wide range of frequencies.

The LFO can be used as a modulation source for a series of modules (for instance pulse width and/or frequency modulation of a VCO, modulation of a VCF cut-off frequency, amplitude modulation with a VCA).

Three outputs are available, with different waveforms: sawtooth / triangle; square wave, and positive-voltage square wave.

The waveform is continuously adjustable from rising sawtooth, through triangle to falling sawtooth. The same control affects the pulse width of the square wave.

A three-way switch can select one of three frequency ranges, spanning from one cycle every few minutes, at the lowest, up to audio frequency at the highest.

Notes: Module A-147-2 is the successor of the VCLFO A-147 but offers much more features than the predecessor. The module is made of these sub-units:

- VCLFO: voltage controlled low frequency oscillator
- VCA: voltage controlled amplifier, switchable to voltage controlled polarizer
- VC delay unit: voltage controlled linear attack envelope (only one parameter: attack) for delayed LFO operation in combination with the VCA (e.g. delayed vibrato/tremolo)

LFO: The voltage controlled LFO has the waveforms Triangle, Sine, Sawtooth and Rectangle available and features a Reset/Sync input. Triangle/Sine and Rectangle are displayed by means of dual-colour LEDs (probably red/green), Sawtooth has a unicolor LED available (probably blue). The output levels are about -4V...+4V for Triangle, Sine and Rectangle. The Sawtooth level is about 0...+8V. The CV control can be switched to attenuator or polarizer ("CV Mode" switch). In polarizer mode the CV inputs affects the frequency in the reverse manner when the CV control is left from the centre position. In the centre position CV has no effect and right from the centre the control works like a normal attenuator. The frequency range (without external CV) is from about 0,005 Hz (i.e. about 3 minutes per period) to 200 Hz (with external CV max. frequency about 1kHz). In addition a ultra-low mode can be activated by means of an internal jumper. When the ultra-low jumper is set a fixed voltage is connected to the switching contact of the "LFO CV" socket. In polarizer mode of the CV control that way extremely low frequencies (up to one hour period and more) are possible. For this a jumper has to be installed on the pin header JP6. In the factory a dummy jumper is installed on the pin header JP7 "Dummy". JP7 has no function and is used only for "parking" of the jumper. Simply remove the jumper from JP7 and plug it on JP6. JP6 is located behind the CV control.

VCA: This is a linear VCA that can be switched to "normal" VCA (i.e. kind of a voltage controlled attenuator) or voltage controlled polarizer ("VCA Mode" switch). In the "normal" VCA mode amplification +1 is achieved with about +5V control voltage. In polarizer mode the amplification ranges from about -0.5 (i.e. inverted signal with about 50% level) with 0V CV to +0.5 (i.e. non-inverted signal with about 50% level) with +5V CV. With about +2.5V CV the signal is suppressed. Details about the functioning of a voltage controlled polarizer can be found in the description of the module A-133. In this mode the VCA can be treated also a DC coupled ring modulator (similar to A-114).

The VCA of the A-147-2 has three sockets available: "In" (signal input), "Out" (signal output) and "CV" (control voltage input).

The Triangle Output of the LFO is normalled to the VCA signal input by means of the switching contact of the "VCA In" socket. If another LFO waveform (or any other signal) should be processed by the VCA the corresponding signal has to be patched to the "VCA In" socket. The VCA can be used also independently from the LFO and the Delay CV. In this case the VCA sockets In, Out and CV have to be patched accordingly. The VCA can be used also as waveshaper for the LFO signals (e.g. by patching VCA In and VCA CV to different LFO signals, if necessary via attenuator A-183-1 or offset generator/attenuator A-183-2).

Attack/Delay: The third sub-unit of the module is a simple, voltage controlled envelope generator that has only the parameter "Delay" (or Attack) available. This unit generates a linear increasing voltage that starts from 0V after each Delay Reset until it reaches about +5V. Then the voltage remains at +5V until the next Delay Reset occurs. The inclination or gradient is controlled by the manual Delay control and the Delay control voltage ("Delay CV" input). The waveform is linear, the control scale is exponential. The output voltage is displayed by a green LED and available at the "Delay Out" socket.

Notes: Module A-147-2 is the successor of the VCLFO A-147 but offers much more features than the predecessor. The module is made of these sub-units:

- VCLFO: voltage controlled low frequency oscillator
- VCA: voltage controlled amplifier, switchable to voltage controlled polarizer
- VC delay unit: voltage controlled linear attack envelope (only one parameter: attack) for delayed LFO operation in combination with the VCA (e.g. delayed vibrato/tremolo)

LFO: The voltage controlled LFO has the waveforms Triangle, Sine, Sawtooth and Rectangle available and features a Reset/Sync input. Triangle/Sine and Rectangle are displayed by means of dual-colour LEDs (probably red/green), Sawtooth has a unicolor LED available (probably blue). The output levels are about -4V...+4V for Triangle, Sine and Rectangle. The Sawtooth level is about 0...+8V. The CV control can be switched to attenuator or polarizer ("CV Mode" switch). In polarizer mode the CV inputs affects the frequency in the reverse manner when the CV control is left from the centre position. In the centre position CV has no effect and right from the centre the control works like a normal attenuator. The frequency range (without external CV) is from about 0,005 Hz (i.e. about 3 minutes per period) to 200 Hz (with external CV max. frequency about 1kHz). In addition a ultra-low mode can be activated by means of an internal jumper. When the ultra-low jumper is set a fixed voltage is connected to the switching contact of the "LFO CV" socket. In polarizer mode of the CV control that way extremely low frequencies (up to one hour period and more) are possible. For this a jumper has to be installed on the pin header JP6. In the factory a dummy jumper is installed on the pin header JP7 "Dummy". JP7 has no function and is used only for "parking" of the jumper. Simply remove the jumper from JP7 and plug it on JP6. JP6 is located behind the CV control.

VCA: This is a linear VCA that can be switched to "normal" VCA (i.e. kind of a voltage controlled attenuator) or voltage controlled polarizer ("VCA Mode" switch). In the "normal" VCA mode amplification +1 is achieved with about +5V control voltage. In polarizer mode the amplification ranges from about -0.5 (i.e. inverted signal with about 50% level) with 0V CV to +0.5 (i.e. non-inverted signal with about 50% level) with +5V CV. With about +2.5V CV the signal is suppressed. Details about the functioning of a voltage controlled polarizer can be found in the description of the module A-133. In this mode the VCA can be treated also a DC coupled ring modulator (similar to A-114).

The VCA of the A-147-2 has three sockets available: "In" (signal input), "Out" (signal output) and "CV" (control voltage input).

The Triangle Output of the LFO is normalled to the VCA signal input by means of the switching contact of the "VCA In" socket. If another LFO waveform (or any other signal) should be processed by the VCA the corresponding signal has to be patched to the "VCA In" socket. The VCA can be used also independently from the LFO and the Delay CV. In this case the VCA sockets In, Out and CV have to be patched accordingly. The VCA can be used also as waveshaper for the LFO signals (e.g. by patching VCA In and VCA CV to different LFO signals, if necessary via attenuator A-183-1 or offset generator/attenuator A-183-2).

Attack/Delay: The third sub-unit of the module is a simple, voltage controlled envelope generator that has only the parameter "Delay" (or Attack) available. This unit generates a linear increasing voltage that starts from 0V after each Delay Reset until it reaches about +5V. Then the voltage remains at +5V until the next Delay Reset occurs. The inclination or gradient is controlled by the manual Delay control and the Delay control voltage ("Delay CV" input). The waveform is linear, the control scale is exponential. The output voltage is displayed by a green LED and available at the "Delay Out" socket.

Notes: Module A-132-3 is composed of two identical voltage controlled amplifiers (VCA). Each VCA has a manual gain control 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 VCA's can be used to process both audio and control voltages. The input has no attenuator available but is capable to process up to 16Vss signals (i.e. -8V...+8V) without distortion.

Notes: Module A-120 is a voltage controlled low-pass filter, which filters out the higher parts of the sound spectrum, and lets lower frequencies pass through. The Cut-Off Frequency determines the point at which filtering takes effect. You can control this manually, or by voltage control (filter modulation, for instance by an LFO). Three CV inputs are available, and the sum of the voltages from these affects the filter cut-off.

The module is based on a so-called "transistor ladder" design, with a cut-off slope of -24 dB/octave, as in various Moog synthesizers. That's what gives it its classic, legendary Moog sound.

Resonance (or Emphasis) is adjustable all the way up to self-oscillation - in which case the filter behaves like a sine wave oscillator.

Notes: Module A-131 provides voltage-controlled amplification. For audio signals, you would normally use the exponential VCA (A-131), and for control voltages, the linear VCA (A-130). It doesn't always have to be that way, though.

The amount of amplification the VCA's provide is determined by the voltage at the CV input, and the position of the gain control, which sets the overall gain in the system.

The VCA has two audio inputs, each with an attenuator. They are amplified by an amount determined by the combination of the gain and the two CV controls.

Notes: MSY2 is an interface that converts the MIDI realtime events Clock, Start and Stop into the corresponding signals Clock and Start/Stop of the SYNC standard. This standard was used e.g. in the Roland devices TB303 bass line or TR808 rhythm composer.

MSY2 is equipped with 2 SYNC DIN sockets (switched in parallel), a Clock miniature jack socket (3.5mm), MIDI-in and MIDI-Thru. SYNC-CLOCK is a periodic signal (0/+5V) representing the tempo. SYNC-START/STOP is a signal that indicates one of the 2 possible states: START = +5V, STOP = 0V. The Clock pin of the SYNC standard is additionally available from a miniature jack socket e.g. for synchronizing the arpeggio input of an analog synthesizer with MIDI.

MSY2 enables the 1:1 conversion of MIDI CLOCK into SYNC CLOCK (i.e. 1 MIDI clock triggers 1 SYNC clock pulse), as well as the reduction of the tempo by dividing the incoming MIDI clock frequency by an integer factor. The factor can be set to any value between 1 and 16 with a DIP switch at the bottom of the MSY2. This corresponds to 96...6 ppm or 24...1,5 ppq (ppm = pulses per measure / ppq = pulses per quarter note). Factor 1 corresponds to the 1:1 conversion. In this case the pulse width of the clock output is fixed to about 4 milliseconds. 16 is the maximum of frequency reduction, i.e. after 16 MIDI clocks 1 SYNC clock appears. For all dividing factors beyond 1 the pulsewidth of the clock signal corresponds to the selected dividing factor.

With two other switches the Start/Stop polarity and the Clock polarity can be changed for special applications not following the SYNC standard.

Notes: Module A-180-4 is a fourfold CV buffer. Buffers are required if the control voltage coming from a CV source shows a voltage drop in case of changing loads or due to other reasons a buffering is required.

For the lower three units the input is normalled to the output of the above unit. That way the module can work as 1-in-4 buffered multiple provided that no signals are applied to the inputs of the three lower units.

Typical applications:

- Buffering the outputs of voltage controlled switches (e.g. A-150-1, A-150-8, A-151, A-152). Comment: in case of bidirectional switches it's not possible to integrate the buffers into the switching module because the direction is not known (i.e. which terminal of the switch is working as input and which as output). All electronic switches suffer from a small residual restistance that may cause a small voltage drop without buffering. This may become a problem especially when VCOs are controlled by the switched voltages.
- Buffering of CV interfaces, quantizers, slew limiter, S&H/T&H, sequencer etc. when VCOs are controlled by the CV (provided that the module in question does not feature a buffered output)
- Buffered multiple (similar to A-180-3)

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: A-134-1 is a voltage controlled universal panning and/or crossfader module. If the module is used a voltage controlled Panning device one audio signal is panned to two different outputs. If the module is used a voltage controlled Crossfader two audio signals are mixed to one common output. The module enables even compositions of both functions.

The module contains two linear high quality VCAs (made with CEM3381/PA381 until April 2013, SSM2164 from May 2013). VCA2 works in the opposite direction of VCA1 i.e. the more VCA1's loudness increases the more VCA2's loudness decreases. The panning or crossfading is adjusted with a control knob (manual control) and by two external control voltages, one equipped with an attenuator. Suitable control voltage sources are e.g. LFOs (A-145, A-146, A-147), envelope signals (A-140, A-141, A-142, A-119), random (A-118), Theremin (A-178) or a voltage coming from a MIDI-to-CV-Interface (A-190, A-191). The panning/crossfading is displayed with 2 LEDs.

A-134-1 has an audio input with attenuator for each VCA. If the audio input of VCA2 is not used the audio input of VCA1 is connected with audio in of VCA 2, i.e. the sockets are "normalled". The module has three audio outputs: Left Output (VCA1), Right Output (VCA2) and Mix. For Panning applications the outputs Left Out and Right Out are used. If the module is used as a Crossfader the Mix Output functions as output.

Module A-134-1 enables voltage controlled stereophonic panning effects (one audio signal distributed to two outputs), crossfading effects (two audio inputs mixed to one audio output with voltage controlled loudness proportion) and combinations of both effects.

Notes: Distortion/Waveshaper module for dynamic distortion of audio signals with extended settings. The applications of this module are waveform modifications and distortion like clipping and waveshaping of audio signals and control voltages (e.g. LFO).

The input is split by the module into three parts, processed by them and then mixed together:

- The original signal which can be amplified or attenuated with the "A" control
- Negative signal component with adjustable and voltage controllable clipping level "-L" and amplitude "-A"
- Positive signal component with adjustable and voltage controllable clipping level "+L" and amplitude "+A"

The amplitude parameters of both the positive and negative components can amplify in a positive or inverted fashion i.e. it can fold the signal. This creates additional harmonics and enriches the sound, creating very living sounds, especially when modulated by dynamic CVs.

Notes: A-137 is a voltage controlled Wave Multiplier. The basic idea of a wave multiplier is to multiply the waveform of an incoming signal (e.g. triangle/saw/sine from a VCO) within one period of the waveform. This leads to additional harmonics of the incoming signal. The period and consequently the pitch of the signals remains unchanged (in contrast to frequency multiplication e.g. with the PLL module A-196).

The A-137 works as a kind of "inverse low pass filter", i.e. it adds a lot of harmonics to a signal that contains none or only a few harmonics (e.g. sine or triangle waveform). In contrast to that a low pass filter (e.g. A-120) removes harmonics from a signal that contains a lot of harmonics (e.g. saw or rectangle waveform). Consequently the best results are obtained in combination with input signals poor in harmonics (e.g. sine or triangle). The A-137 can be used with signals rich in harmonics too (e.g. saw) but the effect is not as remarkable as for triangle or sine waves. For rectangle signals none or only little effects are obtained.

The A-137 is a very sophisticated wave multiplier that offers much more features, more controls and more waveform manipulations than other wave multipliers available so far. In addition all parameters are both manually adjusted and controlled by external voltages. These are the features of the module:

Controls:

- Input Level (to adjust the input level for best effect of the succeeding controls)
- Multiples (number of waveform multiplications, manual control)
- Harmonics (additional effect that adds more harmonics similar to the resonance/emphasis control of filters, manual control)
- Folding Level (controls upper and lower folding level, manual control)
- Symmetry (controls symmetry between upper and lower folding level, manual control)

Inputs/Outputs:

- Audio In (also suitable for control signals)
- Multiples CV In (with attenuator)
- Harmonics CV In (with attenuator)
- Folding Level CV In (with attenuator)
- Symmetry CV In (with attenuator)
- Audio Out (resp. processed control signal output)

The Multiples parameter (manual and ext. CV) defines the number of basic wave multiplications within one period. With the Folding Level and Symmetry parameter (both manual and ext. CV) the upper and lower clipping levels of the wave folder units are controlled. The Harmonics parameter (manual and ext. CV) adds some harmonic content by sharpening the waveform edges and adding overshoot peaks. It works a little bit like the resonance control of a VCF. The module is fully DC coupled, i.e. even control signal can be processed with the modules.

Notes: Module A-137-2 is another version of a wave multiplier. In contrast to the A-137-1 Wave Multiplier I, the A-137-2 generates four phase-shifted copies of a VCO signal applied to the audio input. The four shifted signals are added to the original signal to obtain a fat sound similar to five independent VCOs. The phase shifting is made by a simple circuit that works only for sloped signals like sawtooth, triangle or sine, but not for rectangles or pulses.

The audio input signal (typically a sawtooth, triangle or sine wave from a VCO) is compared with a slowly varying control voltage (CV Shift In). The output of the comparator is a rectangle wave with variable pulse width. When the output of the comparatur is added to the input signal (a sawtooth in the example) with the correct level relation between both signals one obtains a phase shifted sawtooth. The left picture shows the incoming sawtooth wave on top. The two horizontal dashed lines (blue and orange) indicate two different comparison levels. Below the incoming sawtooth the two resulting comparator outputs (rectangle waves) and the two resulting shifted sawtooth waves are shown. It is not a "real" phase shift but an algebraic function. But the result is virtually the same. One could obtain the same function even with several comparator modules A-167 and mixers A-138a/b or polarizing mixers A-138c. But this would require a lot of modules.

The module has available four manual shift controls and four control voltage inputs with attenuators for the four internal shifting circuits. Typical sources for these inputs are LFOs, VCLFOs, random voltages, envelope generators, sequencers or other control voltage sources. Internally eight single outputs are available at single pins: the four shifted signals and in addition four rectangle outputs. A corresponding breakout module with eight sockets is in the planning stage and will be released provided that there are sufficient inquiries. The original signal and the four shifted signals are equipped with internal jumpers. If external toggle switches are used instead of the jumpers each of the 5 signals can be turned on/off individually.

The audio input is equipped with an attenuator to adjust the level for the right summation of the original and the comparator signals (as described above).

Notes: Module A-138 is a four channel mixer, which can be used with either control voltages or audio signals. Each of the four inputs has an attenuator, and there's a master attenuator, so that the mixer can be used at the end of the audio chain - i.e. it can be used to interface directly with an external mixer, amplifier, etc.

A-138a features potentiometers with linear response, so especially suitable for control voltage mixing.

Vintage Edition with a black faceplate and custom knobs.

Notes: Module A-138 is a four channel mixer, which can be used with either control voltages or audio signals. Each of the four inputs has an attenuator, and there's a master attenuator, so that the mixer can be used at the end of the audio chain - i.e. it can be used to interface directly with an external mixer, amplifier, etc.

A-138b features potentiometers with logarithmic response, so especially suitable for audio signal mixing.

Vintage Edition with a black faceplate and custom knobs.