Added an "Amp Mode" to my foot controller

[fret]

So this evening I finally got around to do this "Amp Mode" mod on my foot controller thats been banging around in my head for the last little while. As some of you might know, last year I made a Axefx specific MIDI foot controller based on an AVR microprocessor, and across the top of the controller are 6 knobs that map to EXTERN 1 - 6 on the Axefx (7 and 8 are external expression pedals). They work just like expression pedals, but they are knobs. I've been using them to control the DRIVE1 gain/tone parameters and the DELAY1 repeats/level etc. It makes the controller feel like you have stomp boxes in front of you.

Anyway I got to thinking... lots of amps have about 6 basic knobs right? Things like Gain, Bass, Mid, Treble, Presence and Master? Well wouldn't it be cool to have a switch so I could use the knobs as amp control knobs, then switch back to normal mode, where the knobs send CC's on EXTERN 1 to 6. Well thats now a reality. I wired in the switch, hooked up the software to read it and then made the knobs send sysex set param messages for AMP1. And it works like a charm! The axefx even swaps over to the AMP1 settings page when you start moving the knobs in amp mode. It'll make tweaking patches on the fly in a live situation that much easier.

I also had this idea of one day making an AMP fascia out of a 1RU blank rack unit, that had the same guts as my foot controller, but was permanently in "Amp Mode". Put some nice marshall knobs on it and mount it below the Axefx... now you get direct controller hardware to access the main AMP1 parameters. And to build further on that idea, I've ordered a couple of motor driven pots on ebay to try my hand at making the pots line up with the new values when you change preset. Lets just say thats still very much on the drawing board, but I think I can do it.

Also I've put together a parts catalog and a custom PCB to try and work out what a kit version of my foot controller would cost. What it would contain is all the parts (AVR stamp, PCB, switches, IC's, LED's, LCD etc) and software (source + binary, and ISP to flash the chip yourself) to make the controller. Along with appropriate documentation on the circuit and the build process. Without the case itself I could do the kit for $200 usd + nominal shipping. If there is any interest in such a beasty I'm willing to take to further and get the PCB's printed. FYI the case itself is a hammond alu box, about $60usd or so. US customers would be able to pick that up fairly easily. Alternatively I could make a cut down kit with some sub-set of parts that are difficult to get (the custom PCB, the software and the AVR stamp/ISP e.g) for a lot less. It would depend on the interest level.

 

[voes]

Very interesting!

 

[R.D.]

Very interesting!

Agreed !

 

[Smilzo]

Very interesting!

+2.

 

[srooijens]

I've ordered a couple of motor driven pots on ebay to try my hand at making the pots line up with the new values when you change preset. Lets just say thats still very much on the drawing board, but I think I can do it.

Ah, back to the days way before the Axe-Fx with my Yamaha DG-1000! Pretty good modeling sounds (preamp only but way better than line 6 IMO) with the coolest rotating knobs

S.R.

 

[pneil2]

How about some pics? Sounds very cool.

 

[GiRa]

I also had this idea of one day making an AMP fascia out of a 1RU blank rack unit, that had the same guts as my foot controller, but was permanently in "Amp Mode". Put some nice marshall knobs on it and mount it below the Axefx...

Great idea!!!

The knobs should be assignable. For example in a lot of amps the master is a set and forget, and the level is not.
Also a pair of traditional potentiometers and/or swiches could be useful, you could wire them to ext1 and ext2.

 

[Kwerky]

Definitely cool. So much power when you can design, fabricate and program your own gear.
But now you've proven it works happily in real time via sysex, it makes me wonder why those parameters aren't assignable to Extern controllers. There are plenty of owners who'd love to have them.

With the 1U AMP fascia you could include a toggle switch to switch between Amp1 & Amp2. Actually I have a lot of other ideas for the kind of interface you've built, but it would require a lot more work including writing a PC/Mac front end so users can program the controllers for all sorts of things, maybe adding a multi-position switch to go between the device's programmed banks.
I don't suppose your Axe relies on an external midi clock does it? Wondering what impact a bunch of exp pedal controlled sysex messages have on midi clock messages.
Little Giant is very powerful and I couldn't do without mine, but I don't believe it can send sysex with every expression pedal change. Nor can it handle more than 4 expression devices. And external MIDI controller messages only serve to trigger a preset on or off, they can't pass values.
-- G.

 

[fret]

How about some pics? Sounds very cool.

This is the prototype:




This is the box for the production version:

There are more images here.

 

[fret]

The knobs should be assignable. For example in a lot of amps the master is a set and forget, and the level is not.
Also a pair of traditional potentiometers and/or swiches could be useful, you could wire them to ext1 and ext2.

Currently the knobs in Amp Mode are fixed function, but I could easily make them configurable via the setup menu. Which I'm in the process of re-designing anyway.

Apart from the 6 parameter knobs, there is 2 external expression jacks on the back for extern 7 and extern 8. I plug an expression pedal into them to do wah/whammy/volume stuff.

 

[mortega76]

Keep up the good work!

 

[fret]

With the 1U AMP fascia you could include a toggle switch to switch between Amp1 & Amp2. Actually I have a lot of other ideas for the kind of interface you've built, but it would require a lot more work including writing a PC/Mac front end so users can program the controllers for all sorts of things

I've already been experimenting with a PC/Mac based song list editor:

And I'm planning to revamp the setup menu so that:
- You can assign up to 4 messages to the IA buttons, usually CC's (currently only one msg is possible)
- IA's can be momentary or latching
- IA's can be mutually exclusive (already done)
- You can edit the CC/sysex for each parameter controller (in both normal mode and amp mode)

Hopefully that will all be intuitive enough to not need a PC editor. At the moment the IA buttons are saved per preset, and the extern controllers are assigned global CC's (as you can bind the externs on the axefx to different parameters per preset). However if there was enough interest a PC editor is possible, I'm mainly a software guy anyway.

maybe adding a multi-position switch to go between the device's programmed banks.

Currently you have to scroll through the presets, but you can get to bank B and C... they are just stacked on top of A.

I don't suppose your Axe relies on an external midi clock does it? Wondering what impact a bunch of exp pedal controlled sysex messages have on midi clock messages.

No it doesn't. It does receive axefx tempo messages and display that as a blinking light. You can also set the tempo via the tap tempo button, which sends the tap tempo CC.

 

[Kwerky]

I've already been experimenting with a PC/Mac based song list editor:

And I'm planning to revamp the setup menu so that:
- You can assign up to 4 messages to the IA buttons, usually CC's (currently only one msg is possible)
- IA's can be momentary or latching
- IA's can be mutually exclusive (already done)
- You can edit the CC/sysex for each parameter controller (in both normal mode and amp mode)

Awesome! :shock

Because I have a LGM2, I'd personally just be interested in the 1U AMP fascia with a bit more programming ability. But I think what you're doing with the MIDI pedal is very cool.

I assume you've had a look at the Gordius Little Giant and the latest beta software for the yet to be released new firmware that's still being written?
Site, Latest beta s/w.
Xavier's put together some very cool ideas, and he's remained open to good suggestions and implemented quite a few of them. It's a lot of work, no doubt.
It doesn't have programmable sysex for expression pedals and has a limit of 4 expression pedals.
Your approach of sending sysex messages with 6 to 8 expression pedal/knob values is very attractive.

Hopefully that will all be intuitive enough to not need a PC editor. At the moment the IA buttons are saved per preset, and the extern controllers are assigned global CC's (as you can bind the externs on the axefx to different parameters per preset). However if there was enough interest a PC editor is possible, I'm mainly a software guy anyway.

This is a good thing, once the hardware is done and given enough processing power/memory means there's a heap of potential.

Currently you have to scroll through the presets, but you can get to bank B and C... they are just stacked on top of A.

You're a lot further on than I suspected from your OP.

No it doesn't. It does receive axe-fx tempo messages and display that as a blinking light. You can also set the tempo via the tap tempo button, which sends the tap tempo CC.

Okay. I already rely on the LGM2 to generate midi clock messages to the Axe FX (I don't mean the Axe's tempo sysex messages, nor tap tempo messages to it), another midi FX device and to my PC. I use MIDI Solutions Thru and Merge boxes. I'm aware too much traffic merged together before the Axe FX may cause the occasional bottle neck causing glitches in timed effects.
Sysex messages triggered by expression pedal changes sounds like it might potentially generate a fair amount of MIDI traffic. But I'm relatively new to this, so I ask the question when something cool like this comes along.

Great stuff! :mrgreen

 

[fret]

Okay. I already rely on the LGM2 to generate midi clock messages to the Axe FX (I don't mean the Axe's tempo sysex messages, nor tap tempo messages to it), another midi FX device and to my PC. I use MIDI Solutions Thru and Merge boxes. I'm aware too much traffic merged together before the Axe FX may cause the occasional bottle neck causing glitches in timed effects.
Sysex messages triggered by expression pedal changes sounds like it might potentially generate a fair amount of MIDI traffic.

I could add a "damping" parameter to limit the flow rate of sysex/CC messages from the controllers, like "X" msgs per second or something. The axefx has an internal damping parameter that does the same thing from the receiving end. But so that the MIDI pipe is not saturated with messages the flow control needs to be at the source. Currently I don't have something like that but I could add it easily enough.

 

[pneil2]

Just a quick note on the form factor. Rather than having the knobs
on a pedalboard/controller (since I already have a good one) I'd rather
see it in a rack format. A simple 1-space that I could mount above or
below my Axe-fx so the knobs would be right by the display for the Axe.
Add a midi in (and through?) so that it maintains the power and the bidi
capability of the axe?

I have a buddy that likes the Axe but he's afraid of not being able to
"tweak" his settings on the fly. Ok' he's a little technophobic, but
I understand his hesitation. Just my $.02.

 

[fret]

Rather than having the knobs
on a pedalboard/controller (since I already have a good one) I'd rather
see it in a rack format. A simple 1-space that I could mount above or
below my Axe-fx so the knobs would be right by the display for the Axe.

Thats one of the ideas I've been discussing with interested people. Also a "stomp box" style unit for the amp control is on the cards.

Add a midi in (and through?) so that it maintains the power and the bidi
capability of the axe?

I've got a 2nd midi in port on the next rev of my PCB, and I'm going to have a crack at writing the MIDI merge functionality into the software when I get that built. So it's in the pipeline. I plan to get it to the point where the foot controller / amp control can co-exist with AxeEdit or some other 3rd party MIDI device.

 

[onemoreguitar]

Where in Sydney are you located?? Would love something that works in with my LF Pro.

 

[Man With Gas]

I spoke with Fret today and he's a cool guy who knows what he's doing.

The potential of his project answers the call for an AXE FX Mk11 from many of us who want to turn the physical knobs in real time.

A fantastic idea that makes it a much greater live tool.

I can't wait until he has units to ship. If anyone else is keen on quicker control in a live setting make contact with him ASAP to urge him forward.

 

[stratos]

Behringer makes a control surface that is a desk top unit for around $200.00 USD. (Ebay)
YouTube - BEHRINGER B-Control Fader BCF2000 Demo
This unit has (8) motorized faders, (8) assignable pots on top, and can switch between 4 programmed "scenes"
It is MIDI / USB controlled. MIDI is IN-OUT-THRU / MERGE
One of these could be re-assembled into a 1x19" rack space with a little effort.

 

[Kwerky]

Behringer makes a control surface that is a desk top unit for around $200.00 USD. (Ebay)
YouTube - BEHRINGER B-Control Fader BCF2000 Demo
This unit has (8) motorized faders, (8) assignable pots on top, and can switch between 4 programmed "scenes"
It is MIDI / USB controlled. MIDI is IN-OUT-THRU / MERGE
One of these could be re-assembled into a 1x19" rack space with a little effort.

Reading the manual I don't see how you can program these to send CC values imbedded in sysex messages.
Using them as intended as CC controllers, you can only use a maximum of 8 at a time, and still not be able to adjust the parameters described in the OP.
-- G.