PLAN B analog blog

Hedi - No Problem.

21C:

The VC Direction input of the 21C is a stripped-down version of the
same input in the bigger M21.  Once each incoming clock the 21C looks
at that input.  If nothing's there, it'll go ahead and move one step
forward as usual.  If there is a voltage present however, that voltage is used to determine which step the sequencer jumps to next.  The input scales voltage into 8 divisions.  For instance, somewhere around
ground the sequencer is sent to stage 1. (a little higher, actually, we don't want ground signals to effect it because then if nothing was inserted, the sequencer would think that it had a ground signal and react to that by holding at stage 1).  Somewhere around 6 volts (see, I changed it and that's no problem, there's a scaling trimmer on the input sensitivity) it will go to stage 8.  Any voltage inbetween is fit into one of the eight categories to send the sequencer to one of the remaining six stages instantly.  So if you had a triangle LFO signal that went between 0 and 6 volts, the 21C would do a pendulum. It would travel upwards (stage 1,2,3,4,5,6,7,8) as the triangle rose up, and it would turn around and count down (8,7,6,5,4,3,2,1) when the triangle went down from it's peak and traveled back to ground.

The VC Direction input does not respond to negative voltages, so if you wanted this pendulum action a M10 in LFO mode may work better for you.

Think of this input as a sample and hold in which the sample clock is the incoming clock to the sequencer.



M32:

With no external inputs connected, the two axis of the M32 swing
between the following voltages:

With the Mode switch set to Positive:  ground to +10 volts.

With the Mode switch set to Bipolar:  -5 to +5 volts.

Remember however, the range of each axis is determined by the two
level pots on the module.  Those pots determine the max range. If set
to 12  o clock, that range would be about half (so 0 to 5 volts while
in Positive mode).  Wth it all the way CW, it wold be full amplitude
(O to 10).

However, if external signals are connected to each, then instead of
fading to either low or high voltage, each axis will fade to whatever
signal is inserted.  For instance,  it the same triangle LFO mentioned
above was inserted into the EXT B input, the Y axis would swing from
ground to the full amplitude of the triangle wave, so the Y axis would
work as an attenuator for that LFO's signal.  If another LFO was
inserted into the A input, then the Y axis would crossfade betwen the
two, just like the crossfader on the Model 14 (although not voltage
controlled).

Kind of cool for control voltages, especially considering the M32 has
a combined X/Y voltage output. Imagine four different external
voltages being crossfed. 

But instead of inserting control voltages, let's consider inserting AC
signals.  Then coming out of the X/Y out you will get a four vector
AUDIO CROSSFADER. Now the possibilities really open up.

I hope this helps, feel free to ask any follow-up questions if I
wasn't clear.

- P







--- In PLAN_B_analog_blog@yahoogroups.com, "hpsounds_fr"
<hielo.patagonia.snds@...> wrote:
>
> Hi Peter,
> 
> Model 21C
> --------
> Could you explain us how the VC Direction input (pluged with a LFO,
for example) works with 
> a pulse signal pluged into the Clock input ? Is there something
about the Async or Sync mode 
> found in the early Miltons seq ?
> 
> Model 32
> -------
> What are the uses for the A, B, C, D external input ? Can it be used
for audio signals (vector 
> crossfading) ?
> 
> Many thanks for these innovative modules !
> 
> 
> Best regards,
> 
> Hedi K.
>