Heath
recently i bought a behringer v-ampire . nice amp , FX aren't to bad either . except for one thing the footswitch supplied is an up down job , not handy on stage at all . So i start trolling the net and midi foot controllers are expensive for what they really are , so after some research i found that making one is alot cheaper then buying one and atleast i will do what i need it todo , not what some company wants it todo .
price wise componets are going to cost in the region of R300 , heres what the componet count is sitting at at the moment
1 x pic16f628
1 x 7805 regulator
1 x 5 pin keyboard connector
5 x metal push button swithces
5 x blue leds
and a few resistors and a cap or 2 for the psu smoothing
MIDI is basically just serial communication , and the pic has a hardware serial port and internal clocking , perfect for ease of use .
after some monitoring of the midi port sending information to the amp it was found that it sends simple channel change commands with channel no , easy 3 byte commands .
thats as far as i have gotten so far the simple note tests of the pic showed it will work . i will post info as i continue you on my journey and post some pics as i go along .
AlanRatcliffe
Hi Tailon
Great project. MIDI foot controllers can be expensive and in some cases over-the-top, feature-wise.
So what are you planning? Five switches doesn't seem like a lot - I would have thought at least nine (1 - 5, A/B and bank up/down) or ideally 12 (like a Behringer FCB1010). What about expression pedals for volume/wah (or at least some extension sockets for them)?
Heath
the first prototype will be just 5 switches to solve my immediate problem , once i got all the bugs worked out and working stable , i will move over to the bigger 877 chip , then put in 10 foot switches and bank controls , and a wah as the 877 has a great a/d converter in it .
actually my biggest problem is the mechanics of the volume/wah pedal , need something reliable but i think i'll bug one of the engineers here at work
Heath
A quick Update :
after having coded the software for the chip and running it a simulator , we found a few limitations to the chip , firstly if you use the hardware serial port , you loose 6 pins . so i have been forced to knock the channels avaible down to 4 ( still better then up and down for the time been) and now works great on the simulator . will build the circuit on wednesday night and start dry testing it on a usb midi controller.
one small design change thou is a a/b selector that will knock the amp into a clean channel (automatically) to allow me play with my external pedal .
i have also started coding the software for a mega board similar to the fcb 1010 , 10 channel selectors / a/b selector / bank and external volume / wah pedal with a nice easy to read display . but that one will only be built in december i suspect
Gearhead
Hey Tailon, before I start reading up on the PIC you talk about - would it also work on the receiving end, say, like, switching channels in an amp based on MIDI program change commands? That's on my 'to do' list...
Heath
That exactly what i am doing at the moment .
Btw after much paffing and testing , my little project board midi controller , started sending midi commands successfully to a old onboard midi controller (joystick port) , all seems to be working great (didn't feel like blowing the edirol ) , next step is test it on the edirol and then the amp , should all be done by the weekend.
gearhead , when i am done , i will gladly send you the diagrams , and code i used to program the chips , the PIC chips are available from www.microchip.com , you can have free samples sent to you for nothing *grin* , the 2 i like to use are the 16f628 and 16f877 .
Gearhead
Hi Stig, eh, Tailon 8)
There's other midi switchers and schematics on the net, most of the work imho is in the programming and the User Interface. In capital letters UI!
Just to explain my line of thinking, bear with me a bit:
I am working on a class AB EL84 poweramp design that has a number of switches (relays? LDRs?). Basically it' everything you can't do in a preamp:
1 power bold/spongy (the Mesa/Boogie patent way)
2 rectification tube/diodes (the Mesa/Boogie non-patented way)
3 driver stage 0dB / +6dB (switching in/out the cathode bypass cap and half the resistor)
4 inverter stage with/without feedback (simply switching the feedback circuit on the lower half of the long tail on/off);
5 rough or clean (switching the ultralinear tap on the OPT off or on).
In short, this amp will take you almost all the way from AC30 to Blackface territory except for changing output tubes.
This means there's theoretically 2^5=32 programs possible. Of course, some will not make any sense up front (like current-starving a solid state rectifier) but I'll leave them in for now.
I would like to combine these with the programs I have in my future preamp (Aaagh let me just get the money together and buy that Triaxis!) and effects unit (still happy with my Roland GP-8). Upon one MIDI program number sent to all units there should be one coherent tone, meaning that a single program (like one of our 32) would appear multiple times in the list.
To cut a long story short: every program number in the PIC should contain a binary number between 0 and 31 that it should switch on the amp. Instead of making a UI on the amp allowing one to program that list (costly), there should be a PC program that has a neat UI allowing the user to reprogram the PIC. All the user would have to do is hook up the amp to his PC and download his preferences.
I realise this would also be possible if I had a MIDI patchbay that changes a certain program change message on a certain output channel into another number, but my Roland A-880 can't.
So here's a proposal: if you think this is worthwhile for your purposes we could split the effort. I'll write the PC program if you do the PIC side. How about that?
Gearhead
(bump) Tailon, how about it?
GoeieGenugtig
Alan Ratcliffe wrote:
Great project. MIDI foot controllers can be expensive and in some cases over-the-top, feature-wise.
So what are you planning? Five switches doesn't seem like a lot - I would have thought at least nine (1 - 5, A/B and bank up/down) or ideally 12 (like a Behringer FCB1010). What about expression pedals for volume/wah (or at least some extension sockets for them)?
This seems like an interesting project
This custom pedal can be nice if you are really specific on how you want to control the effects on stage, but is seems the cost can become significant compared to the fb1010 when it is extended to 10 switches, wah and volume. (fb1010 approx R 2000). Especially if it is R300 for a 4 button prototype --> R300 + cost of pots, more switches for final floorboard. I waiting for my last samples from microchip since June :'(.
@Tailon where do they deliver your samples @ work or @ home?
The high quality pots I've seen are quite expensive, and the mechanics can be challenge. I think the idea of sockets can work , and you can use the expression pedals for volume and wah (I must still make sure about that). Electro-optic design may also work for wah if you want to reduce the costs.
Heath
Update :
well after 8 months of not doing anything on this , i have revived the project and have rewritten then code for the chips and after some testing his weekend i have finally got a working model going .
this morning i will head out to my local tronics store and get the push button foot switches , 7 segment display and hopefully a good enough chassis for it , but the switches and 7 segment display are a must right now.
the current project still works off the 628 chip , 5 switches and 6th switch to push the 5 switches to 10 (sorta like a a/b) and a nice led display to show you what channel you currently on . i will post pictures of the circuit the workings in the next few days .
Valie
Tailon, I need something similar to switch my ADA MP1 pre amp. Could you build me one or send me the schematics?
Not_Sean
Hey I'm very interested in making this pedal, as i got the V-amp LX1200H, wanted to know if i supply the funds and parts would you be able to help me put it all together ?
