Doepfer A-113 Eurorack Subharmonic Generator Module
Eurorack Subharmonic Generator Module
Module A-113 is a new sound source that derives from an incoming pulse signal four so-called subharmonics (German: Subharmonische). 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. Pay attention that 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 2 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 adressed).
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.
More detailed information about the Trautonium can be found on our internet site in the Trautonium project article. These additional Trautonium modules are available: Trautonium Manual A-198, Trautonium Filter A-104. The A-111-3 is recommended as control VCO because the A-111-3 has an excellent 1V/octave tracking also for higher frequencies.
Inputs : master frequency (rectangle/pulse input), foot contr. 1 + 2 (gate 1+2)
Outputs: 4 single outputs, 1 mixture output