Hi Kevin,

> Has anyone tries fitting a toggle switch to a A155 module that

would

> allow bypassing the modification That way, one could switch

between

> the new style A155 sequencer and a graphic VCO. Seems simple

enough

> to do.

No, but I've half a mind to do it (it would be interesting to see how
fast it will run without the mod!). There's plenty of space to the
left of the 'trigger outputs' to mount a simple on/off toggle switch:
desolder the join between the resistor and capacitor, then add a
single wire from the end of each to the separate terminals of the
switch. Done.

Tim

>
> --- In Doepfer_a100@yahoogroups.com , "Tim Stinchcombe"

<timothy@t...>

> wrote:
> > Had me more of a think on this...
> >
> > > if the mod is a resistor and a capacitor in the a155
> > > control board,then this is the mod i was telling you
> > > about...it's the mod for letting you clock the a155
> > > from an imperfect clock pulse(with not sharp
> >
> > ...and I don't think this can be the reason (the clock pulse goes
> > through 2 gates anyway, which should sharpen any sluggish pulse

up

> > plenty!). But I do now believe _this_ must be the reason:
> >
> > > edges).also,with this mod ,you can step manualy the
> > > sequencer from the tiny step button more
> > > properly(without almost jumping
> > > steps...).
> >
> > Without the capacitor contact bounce on pushing the clock button
> > could well cause it to skip several steps unintentionally. And I
> > certainly believe this...
> >
> > > but,also,this mod stops the a155 from
> > > running in high audio frequencies!even if you clock
> > > the a155 from an a110 you will notice that,the a155
> > > can't run above a certain speed limit(which is rather
> > > low!)all these are valid only if we're talking about
> > > the same mod,though....
> > > by the way,i removed this mod from two of my a155's
> > > because i want them to be graphic vco's too!
> >
> > ...so if you don't care about the skipping several steps problem,
> > snipping through one of the wires to break the link formed by the
> cap
> > & res will let it run at higher speeds. Details for those unsure
> what
> > we're talking about: the 'control board' is small on the right

hand

> > side of the module, marked 'A-155-4' on underside ('A-155 board

4'

> on
> > top); if you have the mod, on the solderside you'll find a
> capacitor
> > (marked '104') and a 1k resistor (brown, black, red, gold)

soldered

> > together and bridging two pins of the 4011 IC; cutting or
> desoldering
> > either end of them or where they join will do it!
> >
> > Tim