Doepfer

The waveform pictures in the A-137 user's manual are idealized graphs and
used only to explain the basic function of the module. In reality the
clipping and folding is not hard (as shown in the pictures) but soft.
Finally the audible result is important but not the scope picture. You will
find more idealized graphs in other manuals too. Showing the "real"
waveforms, frequency response curves or other parameters would complicate
the explanations.

In the A-137 the combination of the four parameters (multiples, folding
level, symmetry and harmonics) define the output waveform. You should obtain
a triangle output (with A-110 triangle as input) with these approximate
settings:

audio input level ~ 2
multiples = 0
folding level = 0
symmetry ~ 3 (between 9 and 12 o'clock)
harmonics ~ 2 (~ 9 o'clock)

Starting from this setting you should be able to see the functions of the
four parameters very good at the scope.

Your settings are far away from generating a triangle at the output (with
input level at 12'o clock and multiples at 9'o clock you have already some
multiplications).

Best wishes
Dieter Doepfer


> -----Ursprüngliche Nachricht-----
> Von: Doepfer_a100@yahoogroups.com
> [mailto:Doepfer_a100@yahoogroups.com]Im Auftrag von jalmari3
> Gesendet: Mittwoch, 15. August 2007 19:49
> An: Doepfer_a100@yahoogroups.com
> Betreff: [Doepfer_a100] Is my A-137 faulty?
>
>
> I can't duplicate the folded triangle waveforms shown in the A-137
> manual (chapter 2). The shown waveforms consist of straight lines, but
> I get rounded waveforms.
>
> Here is an example oscilloscope view:
> http://www.esnips.com/doc/278f44e2-ce2a-4ff1-8f17-1f7ef5d795d7/A-
> 137_weirdness_1
> (I hope the link isn't too long for Yahoo.)
> The settings are:
> - All CV inputs at full counter clockwise and unplugged
> - Input level at 12'o clock
> - Multiples at 9'o clock
> - Folding level at 12'o clock
> - Symmetry at 12'o clock
> - Harmonics at full counter clockwise
>
> Questions:
> - Is this the expected output on these settings
> - Why does a triangle input get rounded?
> - What settings should give the straight line waveforms shown in the
> manual?
>
> Best regards and thank you for your time
> Jari Jokinen