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

> From: "Dieter Doepfer" < hardware@... >
> To: "Bakis Sirros" < synth_freak_2000@... >
> Subject: AW: 1 Re: Modified my A-117
> Digital Noise Generator
> Date: Thu, 5 Jun 2003 18:58:58 +0200
>
> > Re: Modified my A-117 Digital Noise Generator
> >
> > > The modification requires cutting 4 tracks and
> adding 4 straps (and
> > > is moderately fiddly). If anyone else has been
> experiencing this
> > > frustration, and wants to know the details, let
> me know and I shall
> > > write some instructions and post them (and if I
> can persuade my mate
> > > with the digital camera to visit and take a few
> snaps of it, post a
> > > few pictures too).
> >
> > For those that expressed an interest in this, I
> have created a folder
> > in the 'Files' section containing a text file of
> instructions, and
> > three photos of my modified unit. (Thanks go to
> Mike for the photos.)
> >
> > Any questions or comments, then get in touch!
>
> Roland Mayer informed me about a simple solution for
> the described A-117
> problem.
>
> He found the reason for the problem described: the
> A-117 clock input is DC
> coupled (simply a resistor that is connected to the
> base of a standard npn
> transistor). This leads to problems if AC coupled
> signals are used as the
> capacitors in the AC coupling circuit cause charging
> the transistor base.
> The combination A-111/A-117 is such an example as
> the waveform outputs of
> the A-111 are AC coupled. One solution is to bypass
> the capacitors in the
> A-111 output section (i.e. short circuit the
> capacitors). But the more
> general an more simple solution is to add a 100k
> resistor that connects the
> A-117 clock input to GND (e.g. simply across the
> jack socket). We will
> modify all A-117 in the future and add this resistor
> to all A-117 clock
> inputs.
>
> We will add this item to the FAQ and DIY section in
> the near future.
>
> Best regards
> Dieter Doepfer
> Doepfer Musikelektronik GmbH
> Email address: hardware@...
> Web Site: www.doepfer.com
>

=====
synthfreak(parallel worlds)
athens-greece
1 group owner

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