Doepfer

Hi Bakis

The A136 is one of two modules in the A100 lineup that work as a gain 
stage, the other being the A119 External Input module. All of the 
other modules, including the VCAs, only go up to a maximum of unity 
gain. They're attenuators, not amplifiers.

The A136 is designed to handle both audio signals and control 
voltages, so it does the CV amplification that Florian wants. If I 
patch a CV to the A136's input jack, I can adjust the A 
(amplification) knob to:

Gain = -1  - voltage inverter
Zero gain  - total suppression of the signal
Gain < 1   - attenuation
Unity gain - signal pass-through
Gain > 1   - amplification, as Florian wishes for

If I completely suppress the input signal (zero gain), I can then 
set the +A (Positive signal amplification) knob to unity gain, so that 
the CV passes through only if the voltage is above the adjustable 
clipping level. When used with pitch CV, for example, the output only 
begins to rise after a certain note on the keyboard is reached. If 
this "tracking function" is used to modulate the filter, for example, 
then VCF keyboard tracking is only applied to notes in the upper 
registers, bass notes don't have VCF keyboard tracking applied to 
them. This is the same type of thing that you can do on digital 
synths, and even on more modern analog synths like the Matrix 1000.

The A136 could be used instead of the A119 to boost external audio 
signals to the A100 operating level. It can also amplify internal A100 
audio signals in order to "overdrive" a module to induce a traditional 
distorted sound. (the A131 doesn't sound very good when overdriven, 
but I understand that they're other A100 modules that sound very nice 
when you overdrive them).

The A136 can also be used as a +/- CV source.

The rest, I think, can be found in the A136 User's Manual (I'll leave 
the trigger modifier as an exercise, since I haven't actually done 
that yet). I think the A136 could also be made to work as a 
voltage-controlled on/off switch, similar to the A150, but I haven't 
had a chance to try that either.

The A136 documentation contains some errors and ommissions that I 
noted in an earlier thread.

Joe

--- In Doepfer_a100@y..., bakis Sirros <synth_freak_2000@y...> wrote:
> hi joe,
> please,can you explain further???
> bakis.
> 
> 
> 
> --- buechlerjoe <buechlerjoe@t...> wrote:
> > > So this is what I think: a possibility to amplify
> > a CV-Signal is 
> > really
> > > missing in the A-100.
> > 
> > Not so. This is one of the many possible uses for
> > the A136 
> > Distortion/Waveshaper, the other "Swiss Army Knife"
> > module. It can be 
> > used as a simple attenuator, gain stage, overdrive
> > preamp, voltage 
> > inverter, external signal booster, trigger modifier,
> > and a tracking 
> > function generator. Oh, yeah, it also does
> > distortion, and can create 
> > radical waveshapes from an LFO signal.
> > 
> > Joe
> > 
> > 
> 
> 
> =====
> synthfreak(parallel worlds)
> athens-greece
> [Doepfer_a100] group owner-moderator
> 
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