POD XT & Fender Steel King Controllers - Prototypes

[Bob Lawrence]

I designed this unit in the summer of 2007 and have been using it since. Over the winter I will think about adding a few new features/ changes etc.


How the controller box works:

- It contains a Microcontroller
- It has 8 buttons.
- It has a MIDI out connector (Midi out to the PODXT)
- It has a LCD screen (text display)
- It uses a 9v battery (power)
- It has a Leg clamp (it fits onto the leg of a pedal steel guitar)


The microcontroller is programmed to send MIDI messages when a button is pushed. Each button is programmed to a different User Channel in the PODXT. The POD XT is pre-programmed for each channel. The user channels can be pre-programmed via the Monkey editor or the PODXT itself and you can choose any effect you want on that channel.

What I have programmed:

Button 1 - Preamp - Phase
Button 2 - Preamp - Delay
Button 3 - Preamp - Chorus
Button 4 - Leslie effect
Button 5 - Flange
Button 6 - Digital Delay
Button 7 - Phase
Button 8 - Chorus

Pros:
- Selecting effects is a one button push.
- Externally mounted 9v battery to allow quick changing.
- Small and light weight, portable, fits in the packa seat.
- The PODXT doesn't have to hang of the leg of the
steel guitar. IF your MIDI cable is long enough the PODXT can be placed the floor, AMP etc.


Cons:
- The current LCD screen is not bright enough to read it unless you view it close.
- I don't have a tap control
- The way I mounted it on the guitar leg , it's too low to read the screen but you don't have to read the screen to use it, just press a button. Also, I could use a different mount and try to get it eye level.

It looks a little rough but it's a prototype and not a final design. The case was re-used from another project and has a few extra holes that are not required. Additionally, a few extra holes have been drilled to add features later, such as a controller for the Fender Steel King (to eliminate the giant floor switch box).

Planned future changes/additions:
- Steel King Floor switch eliminator. Just add a circuit and 3 switches to the box. This will allow me to control the Fender Steel King features such as Mute, Tuner etc from the PODXT controller Box
- Brighter screen
- Different Leg mount

Pictures:

[Mike Wheeler]

VERY COOL!! I've dreamed of a unit like this for my ProfexII and Lexicon LXP units. Could your device be used with these? If so, you've got a potential gold mine there.

[Bob Lawrence]

re:my ProfexII and Lexicon LXP units

Mike,

Thanks! for you comments. I don't know anything about those units. Generally speaking, if the device has a MIDI input and is programmable in channels it should work.

For example I searched on the user manual for a LXP-5 :

http://www.lexiconpro.com/product_downl ... Owners.pdf

Page 40

====================================================
Accessing Programs

Up until now, you have used the front panel knobs to save and recall programs. You can also use MIDI to access these programs. All you need
is a device which can send MIDI Program Change messages, such as a MIDI-equipped synthesizer, master keyboard controller, foot controller,
sequencer, or the LEXICON MRC, MIDI Remote Controller (Version 2.0 or higher — you'll need Version 3.0 to access other LXP-5 functions).
A typical MIDI setup is shown below. Connect the MIDI output of the controller to the MIDI input of the LXP-5, using a standard MIDI cable.
====================================================

In this case it would work fine.

Bob

[Bob Lawrence]

@Mike Wheeler

Re:ProfexII and Lexicon LXP units.

In your example you have more than one device to control.

I'm working on a new version with a different microcontroller(new language for programming that will add additional flexibility). I'm trying to decide if I should use buttons and LED's's to select and indicate what effect is selected or a LCD like the prototype.

Your example (ProfexII and Lexicon LXP units) made me think about controlling additional devices. I only use one midi controlled device now but who knows what the future holds. I will make it so the new version can control 2 devices(which is expandable probably up to 6 or more with one microcontroller) and put a extra midi output connector on the box.

New version will be able to control:

2ea - Midi devices
1ea - Fender Steel King Amp

I already have the Steel King switch circuit ready to add to it(or it can be a separate unit in a separate box)

[Lynn Oliver]

Very cool, Bob. Most of the midi controllers are set up for floor use, and I'm not sure that would work that well from a seated position even with a non-pedal steel.

Do you have any idea how long it will run on a battery? If battery life is a problem, you could use a 7-pin midi cable and bring power through the cable.

I'm not clear whether you have the buttons set up as IA's or CC's. Does one press of the button turn on the effect, and a second press turn it off, or is it that each button selects a preset?

[Bob Lawrence]

@ Lynn Oliver

re: Do you have any idea how long it will run on a battery? If battery life is a problem, you could use a 7-pin midi cable and bring power through the cable.

Battery usage won't be a problem. I can calculate battery usage once I select the design options. I'm still experimenting with options i.e. Microcontrollers, LED's, LCD's , etc.. Miccrocontrollers don't use much power but the LCD screen would consume more.

I designed the battery externally on the first unit just for fun.It just seemed like a good idea at the time not to have any covers to pull or screws to remove, for a quick change.I did leave the controller unit powered on in my seat one time and had to change the battery just before I started playing a live show. To be able to reach in the seat and grab a new battery, pull out the old one and stuff in the new one in less that a minute was cool but not necessary.


In theory you could use a 8 pin connector like the Steel Rider does and it supplies the 5 Volts required for the preamp's if the unit your controlling has the same 8 pin jack but I don't see how you could use a 7 or 8 pin MIDI cable in this case because you have to plug it into standard equipment with standard MIDI input jacks.

[Lynn Oliver]

Sorry, should have been more specific. You use a 5 to 7 pin, seven conductor MIDI cable. At the PODxt end you wire the extra two conductors to power. At the controller end you connect the extra two pins to power the box. Probably not a great idea in this case since the PODxt doesn't use +9dc, but if you have a standard supply in your rig for any reason you could piggyback off of it.

I've gone to rechargeable batteries as much as I can, so I tend to avoid 9v batteries because it's expensive buy the recharger and batteries, and 9v batteries have a very low energy density. However, with your external battery pack idea it would be easy to substitute 6 AA's, which should run the box for a long, long time.

[Bob Lawrence]

Steel King Foot Switch:

Approximate dimensions :
7.3" X 4"



New design for the Steel King floor switch that mounts on the leg of your steel guitar.



Units Inches: 3.15(Length),2.13(Width),0.91(Height)

Units mm: 80(Length),54(Width),23(Height)

Front panel design for the new Fender Steel King controller switch box.

The 3 holes on the left are for push buttons(Tuner Mute, Reverb, FX Loop)

The 3 holes on the right are for the indicator LED's.




Leg clamp to mount it on the steel guitar leg:



Jack : For the control cable that goes between the Controller box and the AMP.

[Bob Lawrence]

@Lynn Oliver,

re: Does one press of the button turn on the effect, and a second press turn it off, or is it that each button selects a preset?


Sorry, I think I missed this question. If you turn the effects knob on our PODXT you can see it scroll through the channels. Each button on the control box is programmed to change to a channel. There is a list of available channels in the manual. I can program the buttons for any of those channels. Each time you press a button you are changing channels. Whatever is programed on a channel is controlled by the user.You still have the flexibility of being able to modify what's on the channel, at any time. The only limitation of the controller is the number of channels (by the number of buttons)that you can select.

re:if you have a standard supply in your rig for any reason you could piggyback off of it.

Yes, there is always creative ways to do it. If you had a home made supply you could install midi jacks in the case. You could have a regular midi cable between you commercial device(i.s. effects unit) and the power supply and use a 8 pin conductor from the power supply to the controller box. The only problem with this idea is that you could have some type of electrical interference that you would have to deal with.

[Lynn Oliver]

I get it. I never used a controller with my PODxt, so I wasn't quite sure what level of control was available. I've been thinking about what type of controller would work with my current equipment, which does allow you to turn individual effects on and off within presets, as well as selecting different presets.

[Bob Lawrence]

@Lynn Oliver

OK give me a detailed example for a few channels and I will run a test to see what's possible.

Bob

[Mike Wheeler]

Bob, the more I think about your device, the more interested I become.

My dream is to have a very small push button device that I can use to change the pre-programmed effects that I have worked so hard to create in my devise. And, one that can mount on top of my guitar for instant access to the buttons. I don't need to change effect settings with this device. I just want to select the different programs/presets.

The floor mounted, push button, preset selectors is the idea I like most....I just want it miniaturized.

Not knowing much about midi, maybe I'm being simplistic. but a miniature push button control would be ideal. If more electronics are needed, causing the box to be larger than I envision, maybe they could be mounted in a separate box on the floor, with a small cable interfacing to the control panel at the guitar.

Would this be possible? It sure is exciting to think about!

[Lynn Oliver]

My understanding is that program change commands are used to select presets (channels) and continuous controller commands are used to control specific devices within a preset. The latter are analogous to the bypass switches on stompboxes. The modeler I'm using assigns a specific ID value to each possible device, for example: amp1 is 37, amp2 is 38, chorus 1 is 41 and so on.

So I could press a button on the midi controller to select preset number 23, which might have a tube OD effect included but currently bypassed. Then I could press a different button that would not change the preset but would turn on the OD. I imagine the whole thing can get pretty complicated in order for the midi controller to keep track of and indicate the state of each device, so I'm not suggesting that this would be appropriate for your project.

The third function I need in a midi controller is support for external controllers, such as expression pedals that can be use for things like wah or controller the speed of a leslie sim.

I understand this stuff at a functional level better than I do at a midi command level, so I may not be entirely correct as to how the midi commands are used.

[Earnest Bovine]

If you just want to send MIDI program change messages, you can use an old synth from the attic for that. Back in the 1980s I took an little Casio mini synth to steel guitar gigs for that purpose, but decided it wasn't worth the trouble.