DOEPFER A-107 Manuale

Sfoglia online o scarica il pdf Manuale per Sistemi di filtrazione dell'acqua DOEPFER A-107. DOEPFER A-107 18. System a - 100, multitype morphing filter

Stampa la pagina

doepfer

1. Introduction

Module A-107 is a completely new voltage controlled

filter that has available 36 filter types: different versi-

ons of low pass, high pass, band pass, notch, all pass

and filters with new response curves that have no

name up to now.

Of course the standard VCF controls are available:

manual and voltage control of filter frequency and

resonance. For the filters of the first group (1...18)

self-oscillation is possible, the filters of the second

group (19...36) do not feature self-oscillation. On top of

it a final VCA is available - even with manual and

voltage control. All external control inputs are available

twice: one with attenuator and one without.

The 36 filters are organized in two groups of 18

filters each. The filters can be arranged in 64 different

filter chains. Each chain consists of 32 steps. The

sequence of a filter chain is passed through while the

manual control is operated or the external control

voltage changes from 0...+5V. 64 filter chains can be

programmed by the user and stored in the non-volatile

memory of the module.

System A - 100

The transition between filters can be soft (morphing)

or hard (switching). The morphing time (manual and

voltage controlled) defines the transition time between

succeeding filters from a few milliseconds (switching)

up to about 10 seconds.

Additionally a "clocked" mode is available. This

means that the steps of the currently selected filter

chain are selected one after another. Each positive

transition of the Clock signal calls up the next filter of

the chain. A positive trigger at the Step Reset input

resets to the filter of the chain that corresponds to the

momentary step CV. This allows e.g. to switch bet-

ween the filters of the currently selected filter chain in

sync with a sequencer.

The filter design is 100% analog (CEM filter chip).

Only the morphing control and memory managing is

carried out by a microcontroller.

Remark: Because of technical reasons the transition

between the two filter groups cannot be carried out soft

as capacitors have to be switched. Soft transition (i.e.

morphing) is possible only between the filters of each

group (i..e. within the filters 1...18 or 19...36). Switching

between filters causes a "click" if the filters are from

different groups.

Multitype Morphing Filter

A-107