I’ll state my ultimate question first, here:
How are other people achieving volume-swell volume pedal configuration on iOS, for guitar sounds?
I ask this because I’m not fully satisfied with any of the methods I’ve thus far tried, and maybe others have figured out something simple I’ve missed. I have tried a number of ways to create a full-sweep “volume pedal” in AUM on iOS using both MG3 and plugins; for example, I can connect a CC7 or CC11 expression pedal to:
- The channel volume on an AUM audio channel;
- An audio bus send amount on an AUM audio channel;
- The output volume parameter of some plugins (e.g., IK’s MixBox);
- Cascaded instances of the native Gain plugin in AUM; or
- The output volume of the MG3 mixer.
While these all, technically, work, none are ideal. The first three options can certainly sweep from minus-infinity (or at least minus-enough) to 0dB in one go, but only with a linear “taper” on the expression pedal’s sweep. Volume swells a la Fripp / Hackett / Lifeson really need a nonlinear taper to sound right and be intuitively “playable”.
MG3 can configure a nonlinear taper quite nicely, which is awesome, but even this isn’t ideal because, using MG3 as a plugin in AUM, that plugin comes before the amp sim (to give me the pedalboard FX I’m after), where a volume pedal affects the amount or distortion/saturation during the sweep. I want foot volume it after the amp sim, where the quantity of dirt is the same throughout the volume sweep. Also, I want my volume pedal to come after any noise gates, not before them; an aggressive gate will ruin the bottom part of the sweep.
I’ve lately been experimenting with using the native Gain plugin in AUM, cascaded over multiple instances, to try and get the effect of a nonlinear taper to the sweep. The native Gain plugin will only go down -24dB, but three of them, all tied to the same expression pedal, will certainly go down below the audible threshold, and if I play a little bit with the exact start points of each one (e.g. they all sweep up to 0dB in the end, but if the first one sweeps only from -10 to 0, the second from -20 to 0, and the third from -24 to 0, it does seem to get me a little better taper than a single sweep using a different method. Theoretically one could add as many cascades as necessary to get the taper desired, but that whole enterprise just seems clunky.
I’m not sure why I haven’t been able to find an obvious “volume pedal plugin” that would have a finely configurable taper, or at least a mapping like you can do with, say, MG3 or with curves in the SWAM plugins, but maybe I’m missing something obvious.
Which brings me back to the question I started with: how are other people solving this problem?