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Question Regarding Using Expression Knobs

Warrior

Power User
I built a small box with 2 expression knobs based on Leon's thread/video and added it to my pedalboard as I like the idea of being able to quickly make an adjustment to parameters such as delay mix or feedback, etc. However, I'm having a little bit of trouble understanding how to best take advantage of this.

For example, let's say I have a delay "mix" set to 9% and I want to increase that to about 15% so I turn the expression knob I have assigned to delay mix up to the level I want to hear. Then I change to a different scene or preset and I no longer want that increased mix, I have to turn the knob back down.

I can see how using it to make a temporary change based on a venue or even as an adjustment until you can tweak the preset and save it makes sense, but I'm not understanding how to use it for more than that. Am I missing the bigger picture?
 

Warrior

Power User
Just hook it up to an expression pedal
Well, my example used delay but my question is in general really as this could apply to amp model level, etc.

I currently have an expression pedal that I use for certain things like delay mix and I typically set it so at full-off it's at my preferred minimal mix level and at full-on it's at my preferred max mix level.

The expression knobs are for quick adjustments but I don;t know how to get around the issue I described above.
 

lqdsnddist

Axe-Master
There should be an option to assign an expression control just to a specific channel, so it won’t affect channel B etc

there is no option for a soft taker style setting where the knob control is relative to the new channel settings as that would require an endless rotary encoder, not a control pot with fixed values.
 

LAYGO

Experienced
I think this is why I've always wanted rotary encoders with LED rings like on the AX8 (I've never used an AX8, so I'm guessing on the functionality). I've wanted and paid for some research into a MIDI controller that would use rotaries/LEDs & show you the current value. Change the value, LEDs move with it. Switch patches & then back to your original patch, LEDs shows the original values.

With the potentiometers limited travel, having one up at 80% but loading a patch that has a current value of 20%, move it & you're bang, instant jump to around 80%.

Makes me wonder if there is a way to build a knob box w/o the LEDs so at least you could not jar the values? Maybe using something like this?
 

unix-guy

Legend!
The problem you're facing is that modifiers are shared among ALL channels of a given block by default.

You can select to have the modifier apply to ALL channels or any single channel, but that's it. Refer to the Channels parameter in the modifier.
 

Tom Morris

Power User
Rotary knobs with no start or end point would be ideal but that's more than a simple potentiometer in a box. Its going to take some circuitry and know how. Another option would be use FracPad and buy some knobs forget what the brand was that stick on the ipad screen.

Found it they are called TUNA KNOBS. Basically a knob with a suction cup on the bottom and a stylus tip on it.
 

Warrior

Power User
A smaller version would be great.

The knobs take the place of expression pedals... ;)
Not for what I want to do. An expression pedal gives you real-time control of a given parameter while still using both hands to play guitar. I don't want to use these knobs in the same context. Just to tweak a parameter without having to go into the Axe-FX during the performance.

Or perhaps in another way that I'm not aware of that those others who are actually using them are doing.

The problem you're facing is that modifiers are shared among ALL channels of a given block by default.

You can select to have the modifier apply to ALL channels or any single channel, but that's it. Refer to the Channels parameter in the modifier.
That might be the ticket.

Rotary knobs with no start or end point would be ideal but that's more than a simple potentiometer in a box. Its going to take some circuitry and know how. Another option would be use FracPad and buy some knobs forget what the brand was that stick on the ipad screen.

Found it they are called TUNA KNOBS. Basically a knob with a suction cup on the bottom and a stylus tip on it.
Interesting idea but I don't want to add an iPad to my pedalboard. I'm really just hoping those who use expression knobs in this context will chime in and share their experiences.
 

PincoTech

Experienced
I would use 2 expression pedals, and....
Assign the parameters you want to control to "Perform-Global" on the face of the FRACTAL!

Might not be for everyone, but at the same time, you can't see any "values", on a knob that sits on the floor.
 

Attachments

DLC86

Fractal Fanatic
I think this is why I've always wanted rotary encoders with LED rings like on the AX8 (I've never used an AX8, so I'm guessing on the functionality). I've wanted and paid for some research into a MIDI controller that would use rotaries/LEDs & show you the current value. Change the value, LEDs move with it. Switch patches & then back to your original patch, LEDs shows the original values.

With the potentiometers limited travel, having one up at 80% but loading a patch that has a current value of 20%, move it & you're bang, instant jump to around 80%.

Makes me wonder if there is a way to build a knob box w/o the LEDs so at least you could not jar the values? Maybe using something like this?
Another solution could be the use of motorized potentiometer in something like the old rac-12 which reads the current values of the assigned parameters (via sysex) and moves the pots to the appropriate position when you change scene/preset
 

unix-guy

Legend!
Not for what I want to do. An expression pedal gives you real-time control of a given parameter while still using both hands to play guitar. I don't want to use these knobs in the same context. Just to tweak a parameter without having to go into the Axe-FX during the performance.
What you want is not currently possible. The only way to use an external knob (or pedal) is to "attach" it as an external controller and assign it to a modifier. That gets you what you've already experienced.

Or perhaps in another way that I'm not aware of that those others who are actually using them are doing.
They are using them the same way you are.


When you say "go into the Axe Fx" I assume you mean enter the grid, navigate to a block, get to the right tab, change said parameter?

Do you know about the Perform tabs? They allow you define up to 10 global and another 10 per-preset settings that can be controlled directly from the 5 knobs on the front panel. I think that solves the issue you're trying to solve... Unless your goal is to avoid touching the Axe Fx at all?
 

666was999

Power User
I have bulit something similar. Two foot turnable pots and a switch to switch between the two pots.
That way I have an upper and a lower value and I can control both by foot and I can switch between the two values.

I use it a lot. It's way easier to hit a switch while playing then controling a knob, but still I can change both values if needed.
 

curious

Experienced
I would use 2 expression pedals, and....
Assign the parameters you want to control to "Perform-Global" on the face of the FRACTAL!

Might not be for everyone, but at the same time, you can't see any "values", on a knob that sits on the floor.
Doesn't this solve the issue? You can put several knobs on the preset or global performance page and have immediate access and see values. I have started using it to adjust various parameters on the fly and it works great.
 

Tom Morris

Power User
I have bulit something similar. Two foot turnable pots and a switch to switch between the two pots.
That way I have an upper and a lower value and I can control both by foot and I can switch between the two values.

I use it a lot. It's way easier to hit a switch while playing then controling a knob, but still I can change both values if needed.
Funny some things seem so logical when you see them, never would have thought of that one. Well done sir well done!
 

Mutha Goose

Inspired
I have 2 knobs on the front of my rack going into the Expression Pedal 1 and 2 on the back of the AXE.

The first one is tied to my lead boost (for every preset). This allows me to adjust how much of a boost I get when I switch to my lead channel.

The 2nd knob is tied to a sampler that's buried in the back of my rack. I have a separate output for the samples (this is used at most shows). But this allows me to mix the samples into my guitar outputs which is useful for rehearsals and channel-limited PA systems.

Rack.jpg
 
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