Part two in the Doepfer Trilogy 01/04/04
As we said before Doepfer have released a whole host of products for this years Musik MESSE. We've been down to the Analog Super Booth (run by Andres Schnieders of Schnieders-Buero an amazing display and Andres is as enthusiastic as always) an amongst all of the other analog wonders on display there is a wall of Doepfer kit. The other analog items will be covered in following stories.
The controllers I covered in the previous story (a ribbon controller can be seen in the picture). The picture shows a massive array of A100 modules that were producing sweet noise today. This story moves onto the A100 modules that will be available straight after the show (or have in fact already been released).
The last story will cover prototype modules displayed at the MESSE.
The details that follow are straight from the press releases as Dieter Doepfer knows best....
A-107 Multitype Morphing Filter
A-107 is a 100% pure analog filter realized with the CEM3379 chip that offers the possibility to morph between 36 different filter types. All standard filters are available (6/12/18/24 dB
low pass, high pass, band pass, notch, all pass) but even a lot of brand new filters that have no names so far.
The module offers 64 user programmable filter chains with 32 filters each (each filter within the chain is one of the 36 available filters). Passing through a filter chain can be realized by a control voltage or clock/reset signal. In addition the morphing time
between the filters of the chain is voltage controlled between about immediate switching and about 10 seconds morphing time.
A-101-3 Modular Vactrol 12-Stage Phase Shifter
A-101-3 is a modular 12 stage phase shifter built with vactrols. A vactrol is the combination of a light depending resistor (LDR) and light emitting diode (LED). Vactrols are known for their smooth sound behaviour. For more general details about vactrols please look at the Vactrol Basics page on the Doepfer web site.
The phaser is built completely modular, i.e. the the inputs and outputs of each stage are available as sockets to enable free patching of all stages - e.g. for multiple feedback or forward loops for completely new phaser sounds. The module can be used as two separate phasers too because the vactrols of the stage 1-6 and
7-12 have completely independent controls. Two polarizers are available to obtain positive as well as negative feedback/forward loops.
A-137 Voltage Controlled Waveform Multiplier
A-137 is a voltage controlled waveform 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 by folding the wave at an upper and lower folding level. 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
The result is a kind of "inverse low pass filter", i.e. the module adds a lot of harmonics to a signal that contains none or only a few harmonics (e.g. sine or triangle waveform can be used).
A-149-1 und A-149-2 Quantized + Stored + Digital Random Voltages
These modules are a homage to Don Buchlas 265/266 Module of Uncertainty. A-149 offers four different clocked analog random voltages that are generated in different ways: Two so called
Quantized Random Voltages with "N+1 states" and "2N states" outputs with "N" as a voltage controlled parameter in the range 1...6. And two so-called "Stored Random Voltages" with one equal distributed output and one output with voltage controlled distribution of the
possible 256 output states.
A-149-2 is an expansion module for the A-149-1 and outputs 8
random digital voltages.
A-154 Sequencer Controller
A-154 is an expansion module for the Analog/Trigger Sequencer module A-155. It adds a lot of new functions to the A-155, e.g. voltage controlled step addressing, voltage controlled first and last step of the sequence, voltage controlled running modes (forward, backward,
pedulum, random, one shot), skipping of steps, voltage controlled step length, voltage controlled clock with voltage controlled pulse width and many more.
A-196 PLL (Phase Locked Loop)
It is not very easy to explain the principle of the this module. It contains a VCO, three different frequency resp. phase comparators and a low pass. The basic principle is like this: one of the comparators compares the frequency of an external signal with the frequency of the internal VCO and generates a correction voltage that is smoothed by the low pass and that controls the frequency of the internal VCO.
Ideally the internal VCO follows the frequency of the external signal with some delay that is determined by the low pass
frequency. The module can be used e.g. for frequency multiplication (even voltage controlled in combination with the VC frequency divider A-163), generation of clock signals for graphic VCOs or switched capacitor filters, or even for crazy sound effects by intentional "misadjusting resp. abusing" the module.
A-197 Analog Meter
A-197 serves to display DC or AC voltages by means of an illuminated moving coil meter
with mirror scale. The display range is 0...+10V (resp. -5V...+5V in the offset mode). The module features 3 different measuring methods for optimal display of different sources: direct (especially for positive control voltages), full wave rectifier (especially for audio resp. AC voltages) and offset (especially for bipolar control voltages). The desired mode is selected by a toggle switch.
For further details on these modules and the entire range of Doepfer kit (including sound samples and further explanations of the modules) visit the Doepfer web site (http://www.doepfer.de).
More From: DOEPFER