Doepfer

I'm not looking at the schematic, but it seems likely that it is an inverter AND a +5V offset.  Normally, 5V would invert to -5V, but if you follow that with an accurate +5V offset, 5V in becomes 0V out.  This way, it doesn't matter what the first signal is, how long it is, or what color patch cord you use.  There would need to be a rectifier at the front end so that negative voltages are ignored if you were to patch in a square LFO instead of a gate/clock signal 

I'm not a professional, but this might be exactly how it's done.

Nick 

Sent from the future

> On May 1, 2014, at 8:24 AM, <raccoon_boy@yahoo.com> wrote:
> 
> For example if I plug in a jack lets say with gate lengths of 2 seconds that goes: 5v, 0v, 5v, 0v. 
> It will invert this to 2 second gates of 0v, 5v, 0v, 5v. 
> 
> Simple. 
> 
> But if I plug in a jack and the very first signal is a 2 second gate of 0v followed by 5v. 
> How does it know to change the first 0v to 5v as it has not yet received a 5v signal. 
> 
> Is there some kind of comparitor that 'predicts' the incoming positive voltage before it arrives.
> or does it just default to 5v?
> 
> Cheers
> 
> Dan
> 
>

Dan,

you find my answers written inline.

Best wishes
Dieter Doepfer
__________________________________________________________________

Doepfer Musikelektronik GmbH
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82166 Graefelfing / Germany
registered in Munich/Germany, commercial registry HRB 97 399
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> -----Ursprüngliche Nachricht-----
> Von: Doepfer_a100@yahoogroups.com
> [mailto:Doepfer_a100@yahoogroups.com]Im Auftrag von
> raccoon_boy@yahoo.com
> Gesendet: Mittwoch, 30. April 2014 21:11
> An: Doepfer_a100@yahoogroups.com
> Betreff: [Doepfer_a100] A-165
>
>
>
>
> Hi there havea a couple of questions about the A-165 trigger modifier.
>
> First of all. I understand it can be used as a gate inverter.
> Is a gate inverter essentially the same thing as a NOT (logic) gate?

yes (in contrast to a voltage inverter that inverts the complete analog
voltage including the voltage value, e.g. +3.5 become -3.5V or -6.4 V become
+6.4V). The gate inverter does not consider the exact voltage value but only
the state (low or high). In logical circuits (e.g. TTL) there are typically
3 voltage ranges: low state (e.g. 0...+2.5V), undefined state (e.g. +2.5 ...
+3.5V) and high state (e.g. +3.5 ... +5.0).

> Secondly.
>
> I see the gate inverter will convert 5v to 0v, and from 0v to 5v.

No. For the A-165 any incoming voltage beyond about +2V (i.e. ~ 2 ... 12V)
will cause the inverted output turn to low (close to 0V). Any incoming
voltage less than about +2V will cause the inverted output turn high to a
value close to +12V. The manual is a bit vague concerning the in/output
voltages. The reason is that the A-100 is very "tolerant" concerning logic
levels. Any voltage beyond about +2.5V is typically treated as "high". This
is because each digital input (clock, gate, trigger ...) is usually equipped
with an input transistor stage that responds to voltages beyond about +2V.
Consequently any voltage in the range +2 ... 12V can be used to trigger the
digital input of an A-100 module. The only exception is the gate input of
the A-112 which requires at least +5V (+5...12V) as it has no input
transistor stage.

> This is great, but must it receive a 5v signal first so it knows
> what value to change the 0v signal too?
>
> It doesn't seem to specifiy this in the manual online and I
> haven't purchased one yet so was wondering if anyone could clear that up.
>
> I'm guessing either
> a) it needs a 5v signal first (to know what to convert 0v to)
> or
> b) it defaults to 5v (perhaps changeable by internal jumper)
>
> Cheers
>
>
> Dan
>