> Hi!
> I am new A-100 owner and i have a question about how can i retrig
> while i play with my midi keyborad
> you know the mode retrigger as some analogue synths have(SH-101&Pro one)
>
>
> but i don't know which module do that

The retrig feature has to be carried out usually by the CV/Gate transmitter
(e.g. the Midi-to-CV interface). For example the A-190-2 or the MCV4 the
retrig function (i.e. if a new gate signal is generated while playing
legato) can be turned on or off by the user.

In the past so-called pitch-change detectors were available that generated a
trig pulse whenever the pitch (or any other voltage) changed. Usually the
inverted signal with "on" in the neutral state was generated and a short
reset to zero whenever the pitch changed. It's nothing but a high pass
filter followed by a full wave rectifier (to recognize both positive and
negative changes) and a gate shaper (e.g. to obtain a certain length, e.g. 5
ms). But in newer designs the retrig selection is chosen in the CV/Gate
source.

Best wishes
Dieter Doepfer