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NEW INFO ABOUT THE A107 MULTITYPE FILTER.(FROM DOEPFER).!

NEW INFO ABOUT THE A107 MULTITYPE FILTER.(FROM DOEPFER).!

2002-10-25 by bakis Sirros

DIETER DOEPFER SAYS:
  "here some technical information concerning the
 A-107 (this may concern your poll too):
 
 The different filter types result from switching of
 electronic parts (resistors, capacitors) and filter
 stages. This causes some restrictions concerning the
 morphing possibilities: different resistors and
 filter stage switching can be replaced by VCAs. But
 it is not possible to obtain a smooth transistion
 for 2 different capacitor values in the circuit.
 This means that morphing with with VCAs is only
 possible for those filters that have the same
 capacitor values.This divides the filters in 2
 groups. Within each group morphing is possible using
 VCAs. But it is not possible to morph between
 filters that differ in capacitor values.
 The VCAs have to be high precision types concerning
 the absolute amplification factors (this is normally
 to that important in an analog modular system,
 normally there will be no problem if the the
 amplification 0.95, 1.0 or 1.05 for +5V control
 voltage). But for the A-107 filter morphing it
 essential to obtain exact amplification values.
 This leads to these basic versions of A-107:
 
> 1. Minimal version (as described so far): A certain
> amount of different filters (e.g. 32) that can be
> switched (not morphed !) via up/down buttons or
> voltage controlled, approx. price 150 Euro.
> 2. Morphing version 1: Precision VCAs controlled by
> DACs enable morphing within one filter group,
> approx. price 200...300 Euro (we still have to look
> which VCAs and wich DACs are suitable and at which
> price).
> 3. Full morphing version: This will require that the
> complete filter section is built twice (once for
> both capacitor types) so that even morphing between
> both groups is possible, approx. price 300...400
> Euro.
> 
> For all three cases a 3-digit display will be
> included to show the current filter type.
> 
> You may forward this info to the group (no response
> from until Nov. 04 as I'm not in the company next
> week). 
> Best wishes"

> Dieter Doepfer
> Doepfer Musikelektronik GmbH
> http://www.doepfer.de
> email: hardware@doepfer.de 


SO,I THINK IT WOULD BE GOOD TO CREATE A POLL WITH
THESE THREE VERSIONS AS POSSIBLE CHOISES,RIGHT?
BAKIS.




=====
synthfreak(parallel worlds)
athens-greece
[Doepfer_a100] group owner-moderator

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