Chorus module DIY equivalent?

[davep]

Hi all,

I've been working on some external effects processor patches and I have run into a puzzle. When using the G2 (or any other outboard effects processor) with the effects sends on a mixing console, you want to be able to create the effect in the outboard device and bring the effect back into the console with the effect 100% "wet", meaning with none of the dry signal mixed in with the signal coming back from the effects device. This is important for two reasons -
1. So you can bring up the effect without increasing the volume of the dry track (which would happen if the dry signal is also coming back into the console mixed with the effects), and
2. To avoid unpredictable phasey mess caused by outboard gear that has A/D-D/A conversion, which will bring the dry signal back into the console with some slight delay and affect the sonics of the dry signal when the two signals mix.

So this is all easy to do when creating various reverb and delay and pitch shifting effects, because the modules involved in these effects allow you to build a signal chain that does not pass the dry signal to the output (the pitchshifter is 100% wet unless you add a mixer to change that, and the reverb has a mix control that can be set to 100% wet, etc.).

BUT - Then there is the Chorus module. I really like the sound of this module and it would be great to have this effect available for external signal processing, but the Chorus module passes the dry signal to it's output in a 50/50 wet/dry mix when the Amount control is set to max. Bah! This results in the two problems described above when you use it on a console effect send.

So does anyone know how to replicate the sound of the Chorus module using DIY patching so you can omit the dry signal from the output? I have tried various tricks with short swept delays but I can't get it to sound the same. Thanks!

[ian-s]

I thought I stumbled upon it when experimenting with 3 phase modulation, going to 4 phase sounded too much like the built in chorus so I discarded it.

1 lfo generates 0,90,180,270 triangles and modulates a quad delay in the 25ms range. Summed output is added/subtracted to left/right for stereo.

Maybe the stock chorus uses sine instead of triangle? And a little filtering?

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DIYchorus.pch2
Description:		Download (listen)
Filename:	DIYchorus.pch2
Filesize:	2.11 KB
Downloaded:	1499 Time(s)

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[Afro88]

Hi Dave,

Try adding a phase inverted version of the dry signal in.

I did a quick patch to make sure this works. Load into slot A, and the button on the right when off passes through just the chorus module, and when pressed passes the chorus, plus phase inverted dry, plus normal dry. There is no difference between the two, so adding a phase inverted dry signal will give you a 100% wet signal

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wet chorus.pch2
Description:	Patch to subtract dry signal from chorus module, and prove this does provide 100% wet	Download (listen)
Filename:	wet chorus.pch2
Filesize:	1.23 KB
Downloaded:	1255 Time(s)

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[davep]

Hey, thanks you guys. Ian, that sounds nice! And afro88 - DOH! Of course! I had tried inverting the ENTIRE signal to try to cancel the dry signal coming from the G2 with the original dry signal at the console once the two signals got re-combined at the console, but that didn't work because of the slight A/D-D/A latency coming from the G2. But when you do it this way, cancelling the dry signal with itself entirely inside the patch, it works! The dry signal never gets out of the G2. Cool.