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Fwd: AW: [Doepfer_a100] Re: Updating the a-120 (dieter's answer)

2004-08-25 by Bakis Sirros

--- Dieter Doepfer <hardware@doepfer.de> wrote:

> From: "Dieter Doepfer" <hardware@doepfer.de>
> To: "Bakis Sirros" <synth_freak_2000@yahoo.com>
> Subject: AW: [Doepfer_a100] Re: Updating the a-120
> (was: q's)
> Date: Wed, 25 Aug 2004 13:25:23 +0200
> 
> 
> > > Which resistor needs to be changed, from what
> value, to what value?
> > >
> > > I would very much like to experiment with my old
> a120.
> >
> >
> > hello julian,
> >
> > don't know exactly. i think that dieter doepfer
> can tell us.
> > maybe he is reading this and can give some
> details.
> >
> > best wishes
> >
> > ingo
> 
> These are the resistors for the first filter modules
> that determine the
> input level resp. distortion feature:
> 
> module	resistor	factory value	location
> A-120		R15		22k			just behind the audio level
> control
> A-121		R1		220k			just behind the audio level
> control
> A-122		R1		100k			just behind the audio level
> control
> 
> Reducing the resistance causes a higher level (e.g.
> dividing the resistance
> value by 2 causes to double the audio level, e.g.
> 10k for R15 of A-120
> doubles about the level) and may generate distortion
> for high input levels.
> 
> We are about to add some information how to
> increase/decrease the
> sensitivity of audio inputs, control inputs and
> manual controls (e.g. VCO
> tune, filter frequency) to the DIY page. It is
> always a simple resistor that
> has to be changed.
> 
> Normally the basic inverting opamp circuit is used
> to add several voltages
> (essentially the "CV mixer" in the DIY document). By
> altering the values of
> R1, R2, R3 and R4 the sensitivity of the inputs In1
> ... In4 can be changed.
> 
> Best wishes
> Dieter Doepfer
> 
> 


=====
Bakis Siros
Parallel Worlds / Polariton
Athens-Greece
[Doepfer_a100] group owner
http://www.shimarecords.co.uk
http://www.ward12.com


		
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