ARP odyssey/ wonky square waves?

[stinkyfingers]

phase shift

[sctt_stone]

They kinda look like a half circle with a Saw wave sitting on top of it.

[Space Station]

have you checked the scope?

[sctt_stone]

[QUOTE=Space Station;8366600]have you checked the scope?[/QUOTE


The scope in this case is Soundexplorer, software, it is freeware.

[stinkyfingers]

can you post a pic?

[sctt_stone]

Sorry, I meant AudioExplorer.

[sctt_stone]

[stinkyfingers]

like this...?
if so, then that is phase shift from a HPF...

[sctt_stone]

Hmmm, and this is with the High pass filters all the way open.

[stinkyfingers]

what is your A/D converter...?

[sctt_stone]

Apogee Ensemble.

[stinkyfingers]

if it is not from a filter in your synth, it could be from a filter in your converter.
most of the Apogee's i've seen have a HPF, but i have never tested the Ensemble personally...

[Dave Peck]

That's normal for an Arp Odyssey. And the shape will change a bit as you play higher and lower notes.

[sctt_stone]

So is it still a square wave in actuality?

[NWSooner]

When I had the Lumina mod done to my Oddy I also had the "Audio Path Upgrade V2.0" done to it, which includes the following description:

This mod now includes a high-pass filter bypass switch. Analysis using a good quality oscilloscope on the output of a stock Odyssey reveals that when the high-pass filter slider is all the way down, the circuitry is still removing quite a bit of low end from the signal path.

Odyssey mods

[sctt_stone]

Will loss of bass result in a changed wave shape? Also, if you have had the envolopes modded on your ARP would you be kind enough to post an example of the attack at its fastest setting? I would love to hear how much of a differance there is.

Originally Posted by NWSooner

When I had the Lumina mod done to my Oddy I also had the "Audio Path Upgrade V2.0" done to it, which includes the following description:



Odyssey mods

[Necron 99]

Originally Posted by NWSooner

When I had the Lumina mod done to my Oddy I also had the "Audio Path Upgrade V2.0" done to it, which includes the following description:



Odyssey mods

You mean Phil Cirocco gets his ass up and actually does what his fancy little website promises? I'm shocked.

[stinkyfingers]

Originally Posted by sctt_stone

Will loss of bass result in a changed wave shape?

what is mostly responsible for the waveform change in the case of a HPF is not the actual "level" change of the root/partials, but the phase change...

[stinkyfingers]

this is a somewhat "crude" example because i only used a few harmonics, but this is an illustration of the effects of HPF on a square wave*...

pic 1 > here we have 5 sine waves (1k > 9k, odd). notice the phase relationship they have.

pic 2 > this shows the 5 sine waves and their "sum" (white), which is a square wave.

pic 3 > here are the sine waves after a HPF is applied. notice their phase has shifted and they no longer have the same "relationship" as in pic 1. (note the fundamental (blue) has been shifted significantly.)

pic 4 > this shows the "sum" (white) of the sine waves with the HPF applied.

(*i know this is technically not really a square wave but it is close enough for this example...)
(sorry if all the bright colored squiggly lines are a little confusing...)

edit: here's a nice animation of how this gets constructed one sine at a time...SquareWave.gif

[sctt_stone]

Thank you for the above post. This is why I love Gearslutz, there are so many knowlegable people willing to share that knowledge.