How to make an octaver

cheesycheek's icon

Hi,

I'm very new to Max/MSP and I'm trying to make some effects for my guitar (which will be controlled by an Xbox Controller). I already have reverb and delay; now I'm wondering how to make an octaver.
Can u give me some advice?

Thx!

brendan mccloskey's icon
Max Patch
Copy patch and select New From Clipboard in Max.

Hi
arguably the quickest/cheapest/simplest method - besides using a dedicated external - is reading from a delay line, eloquently demonstrated by dude837 on youtube (why do I find myself typing those words regularly??):

Brendan

brendan mccloskey's icon

And I recall an extensive recent thread about pitch shifting in a guitar-pedal stylee:

Brendan

Peter McCulloch's icon

You could look at the transposition examples in the Examples folder that comes with Max.

Max Patch
Copy patch and select New From Clipboard in Max.

The classic stompbox octave pedal is a little different, however, IIRC. It involves a Schmitt Trigger (which is a two-stage comparator: thresh~ works for this) which alternately inverts the waveform.

Alternatively, some pedals just do full wave rectification. You can do this with
abs~ -> cross~ 20 (use the right outlet of cross~)

Cross~ removes the DC offset that rectification introduces.

brendan mccloskey's icon

I regularly forget about native tools!

[gizmo~]

cheesycheek's icon

Thank you very much for your answers!

roger.carruthers's icon
Max Patch
Copy patch and select New From Clipboard in Max.

See also ring modulation using pitch tracking, such that your modulating wave is always half the frequency of the input, a la Puckette book p.135.
Only as good as your pitch tracking, of course, but works well enough with simple guitar melodies.
The example below uses sigmund~ for the pitch tracking,
Cheers
Roger