[sdiy] Sampler mode...

[Andre Majorel]

On 2008-11-17 01:34 +0000, Seb Francis wrote:

> Been jumping ahead of myself a bit and thinking of applications
> for the  digital module I'm designing.  One possible extension
> of the 2xD delay  might be 'sampler mode'.  I spec'ed it out
> something like this....
>
> (Remember that old black Akai sampler, was it S612 or something,
> that  had the 2 sliders to set the sample start & end points and
> they could be  reversed to reverse the sample?  Always missed
> that feature on my newer  samplers...)
>
> CV1 = Playback start point for channel 1
> CV3 = Playback end point for channel 1

Do you plan to quantise the start/end points to the nearest zero
crossing ?

Is looping meant to always loop from end point to start point ?
Eight points might be a little much but three points would come in
handy. I can see three switches :

- LOOP : whether to loop after END

- USE MID : point to return to after END (MID if true, START otherwise)

- PING-PONG : if true, returning means playing the same range backward
    and negated.

That gives five useful modes :

LOOP	USE MID	PING-P	Effect
Off	x	x	[START - END]
On	Off	Off	[START - END] ...
On	Off	On	[[START - END] ![END - START]] ...
On	On	Off	[START - END] [MID - END] ...
On	On	On	[START - END] [![END - MID] [MID - END]] ...

Demos of "ping-pong" playback, with and without inverting the
polarity on pong :

  http://www.teaser.fr/~amajorel/misc/loop_fwd.flac
  http://www.teaser.fr/~amajorel/misc/loop_fwd_back.flac
  http://www.teaser.fr/~amajorel/misc/loop_fwd_back_inverted.flac

-- 
André Majorel <URL:http://www.teaser.fr/~amajorel/>