[sdiy] TB303 Slide

[Adam Inglis]

When you guys have all finished re-classifying portamento in  
electronic instruments, could we lay people have it summarised for us  
in non-mathematical terms please?
::wink::......

Adam
On 11/06/2012, at 5:33 AM, Richie Burnett wrote:

> Tom Wiltshire wrote:
>
>> Could we just say "RC glide"?
>> It's simple, descriptive, and it leaves to one side the question of  
>> whether it's constant time or not!!
>
> "First-order RC lag" with fixed time-constant of approx 22ms.   
> (Exact TC varies slightly from unit to unit with the tolerance on  
> C35.)
>
> When sliding from an old note to a new note the oscillator CV  
> follows this equation:
>
> Vpresent = Vnew + (Vold - Vnew) * exp(-t / 0.022)
>
> where Vnew is the new note's CV, Vold is the old note's CV, t is the  
> time in seconds since the slide was invoked, and Vpresent is the  
> instantaneous pitch CV.
>
> The start of the slide process is always audible because the  
> sequencer holds on the gate from the currently playing note then the  
> pitch CV starts slewing towards the pitch of the new note.  How much  
> of the end of the slide process you hear depends on how long the  
> second note is programmed to be.  If you slide to a 16th note at a  
> brisk tempo you might not hear it get anywhere near the destination  
> pitch before the note is snuffed out by the gate line dropping low.   
> Arbitrarily extending the programmed length of the second note will  
> easily allow you to hear as much of the slide as you want.
>
> -Richie,
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