[sdiy] Sampler mode...

Seb Francis seb at burnit.co.uk
Tue Nov 18 13:50:04 CET 2008

Andre Majorel wrote:
> Do you plan to quantise the start/end points to the nearest zero
> crossing ?

Well, I'm not sure.  I'm going to have to experiment and see what works 
in practice.  Certainly I will have to do either this, or provide a 
short fade in/out.  Quantisation may not be a bad thing as it will 
reduce the effect of CV jitter caused by noisy ADC sampling.

> 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.

Well yes, it does sound useful to be able to set the loop start 
independently from the playback start.

I could add a CV for loop start point .. giving 3 position CVs:
- Playback start
- Playback end = loop end
- Loop start

If playback start > loop start then ignore loop start.  Thus by setting 
the loop start to the minimum, the playback and loop start points can be 
controlled with a single CV.

Ping-pong might be interesting ... and sometimes it helps to loop 
samples that would otherwise be very glitchy.  To avoid clicks it would 
have to be have to be aligned to zero-crossings as well as inverted 
polarity while reversing.


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