"Anyone know of a stompbox that will auto fade-in an FX loop?"

[cmcmahan]

I'm looking for someone to build me a stomp box that will auto fade in an FX loop using a dry signal similar to a Xotic  Splitter/Blender pedal,  but with a pedal instead of a fade-in knob.

[Mark Hammer]

Toadworks has an envelope controlled cross-fade pedal.

[R.G.]

Mark probably remembers me blathering about this process from years past.

I actually wanted to do this with a number of cross-fades, three or more, which I decided was more like effects "morphing" than fading. 

I actually have a skunk works pedal that may become a product that does this. With that as background, any fading technique works if it can be voltage or current driven. The details of how to make that happen are specific to the controlled fader employed. It could be as simple as using two LDRs and out-of-phase LEDs on the panner from "Panning for Fun" at GEO.

[skjaldborg]

Apologies for restarting an old thread.

Did this idea go any further? It's something I have been playing around with for some time (back burner project). Currently putting together some VCAs. The way I planned this was much more like a modular synth - to build a basic mixer box with several voltage control inputs (0-5 v) which would give the option of many different control fade options. Obviously more boxes takes up pedal board space but I figured it would be good for  DIY designers to jump in with different control options. The mixer box would probably have envelope out (possibly trigger). Control modules could be the obvious LFOs, ADS (difficult to do an R with a sound that's not there!). I have also messed around with a sequencer control in the past (like ZVEX but with triggers to fire one iteration).

Paul

[scuzzphut]

I'm looking for someone to build me a stomp box that will auto fade in an FX loop using a dry signal similar to a Xotic  Splitter/Blender pedal,  but with a pedal instead of a fade-in knob.

So, the amplitude of the dry signal controls the amount of FX loop in the mix ??

If not - what is the trigger for the fade in ? If it's stomping on a switch, couldn't you just stomp on an expression pedal instead - maybe using that to control a crossfade mixer ??

[pgiorgio61]

well, probably nobody there but... I made it!
have a look at Instructables:

https://www.instructables.com/RC-1-Loop-Station-BOSS-Modification-FADE-and-STOP-/

and

https://www.instructables.com/Fade-for-Guitar-Looper-and-Tremolo-for-Free/

https://drive.google.com/file/d/1EIBp-IhNwmCaV-6RrxoW4x0F7jSyLH7Z/view?usp=sharing

[idiot savant]

Shameless self promotion:

https://spacemaneffects.com/collections/equipment/products/mission-control

It will also do:

splitting
mixing
tremolo
double-beat tremolo(using the phase switch)
volume swells
etc

Basically its a VCA with a parallel clean blend. Phase switch on the VCA path. And a multi-mode envelope generator to control the VCA.

[iainpunk]

well, probably nobody there but... I made it!
have a look at Instructables:

https://www.instructables.com/RC-1-Loop-Station-BOSS-Modification-FADE-and-STOP-/

and

https://www.instructables.com/Fade-for-Guitar-Looper-and-Tremolo-for-Free/

https://drive.google.com/file/d/1EIBp-IhNwmCaV-6RrxoW4x0F7jSyLH7Z/view?usp=sharing

i don't think you actually looked in to what the tread is about...
its about a loop switcher, a thing that fades in and out an FX loop so you can turn on and off multiple pedals with a single switch, it has little to do with a loop-station like you posted

cheers, Iain

[BJM]

VCAs, LFO's, too difficult for me. But I recently read a post here about a noise gate (AQR?) with a swell option. Wouldn't even need a switch, just a loud strum. Or an extra swell pedal first in the chain? Not auto but an expression pedal instead of the blend pot?

But maybe I don't understand the question? Press a switch, fade-in, fade-out etcetera until the switch is pressed again?

Old thread btw, I'm not sure it it's the same pedal but the pot on the Xotic X-bender looks lik a blend pot to me.

[iainpunk]

VCAs, LFO's, too difficult for me. But I recently read a post here about a noise gate (AQR?) with a swell option. Wouldn't even need a switch, just a loud strum. Or an extra swell pedal first in the chain? Not auto but an expression pedal instead of the blend pot?

https://www.diystompboxes.com/smfforum/index.php?topic=119340.0

[Mark Hammer]

The time constants of any sidechain-controlled effect or utility will depend very much on the nature of the effect.

For instance, the attack time on a noise gate (which turns things "on") will generally need to be a bit slower than the attack time on a limiter/compressor (which tries to rein in the peaks).  The attack and release time of envelope-control of phaser speed will need to be slower than the respective time constants of an autowah.  And so on.  In some instances, having the desired change occur in a very punctate way can be jarring and disruptive, while in other cases if it is too slow it won't accomplish what needs doing.

So, envelope-control over morphing into, and back from a loop, will require some thinking and probably trial & error testing, of the time constants of the sidechain.  It obviously can't be too responsive or else "mis-picks" will bring the loop in at times when you don't want it.  It can't be UNresponsive, either.  The right degree of responsiveness will also rest on how perceptibly smooth the transition is.  I get the sense from the OP that what is desired is not a complete changeover, but rather a proportional blend.  That is, the harder I pick, the more apparent the effect is.  The "clean" signal may well never completely disappear, but the loop processing just becomes more obvious.

My sense is that one needs a larger averaging cap for that, which will effectively "sum" successive strums, and not reach maximum with a single pick/strum...at least not often...and gradually fade back.

At first blush, one need only use an LDR in parallel with a mixing resistor in an inverting op-amp/mixer configuration.  Let's say Rf = 100k, R1=47k, and R2=470k, with R1 feeding the non-loop signal, and R2 feeding the loop.  The gain of the non-loop is a little over 2x, while the gain of the loop is much less than unity.  If our envelope follower drives a vactrol, whose LDR is in parallel with R2, picking harder (and of course using a suitable LDR value) will reduce the combined parallel resistance of R2 and LDR, making the loop more audible.  Get the time constants right and you'll get a pleasing fade-in/fade-out.  But here's the thing: it will also increase the amplitude of the combined signals.  And that may be disruptive.  The objective, then is to change the mix without changing the volume level....unless that's what you want.

[Kipper4]

I once used Electric Druids cross fader and an envelope detector to control the fade.
Similar to the toadworks. Trouble was the cross fading can add some noise and it doesn't sound smooth. Plus it depends on the effects used in the effects loop.
Lots of fun.

[BJM]

VCAs, LFO's, too difficult for me. But I recently read a post here about a noise gate (AQR?) with a swell option. Wouldn't even need a switch, just a loud strum. Or an extra swell pedal first in the chain? Not auto but an expression pedal instead of the blend pot?

https://www.diystompboxes.com/smfforum/index.php?topic=119340.0

Thanks Iainpunk,

that's the one. Is there some final schematic for this? I noticed after posting the third or so there still was some discussion going on. Would be fun to try to combine that with a splitter/blender.