FCB1010 Mod

Noumenon · April 21, 2005, 08:44:46 PM

So, you might have seen that webpage regarding the FCB1010 mod.
I'm doing a version of that at the moment. However there are some things I wonder.

First, the expression pedals are regulated with a LED, a LDR and two resistors.
Schematic below:

How do I mod this so I can put a connector there to use with ernie balls?
In other words; how can I reduce that circuit from LED+LDR to one Potentiometer?

Secondly, the stomp switches them selves have a diode after them, is this just to make sure that the current won't travel the other way? Can I ignore these?
Schematic below:

Rodgre · April 21, 2005, 11:02:55 PM

Please! Link me to the mod site. I haven't heard about this at all and I would love to mod mine for remote setup (a remote footswitch that triggers the 1 button)

Roger

Noumenon · April 21, 2005, 11:05:28 PM

http://xsive.net/html/fcbmod.html

Not sure it's what you're after.
The mod is only to get it all in another box and have the pedals external.

Rodgre · April 22, 2005, 08:36:08 AM

Interesting. Like all Behringer stuff, it seems like there's barely anything inside that thing!

I think I'm going to try a mod.... I just want to have two external footswitches that are redundant for the 1 and 2 button on the FC. I would like to have a small footswitch setup on stage for triggering samples, instead of the huge FC, since I'm using three pedalboards at the moment.

http://www.rogerlavallee.com/news/data/upimages/pedalboards.jpg.w560h419.jpg

Roger

Noumenon · April 22, 2005, 11:31:33 AM

okay, so you want to replace the footswitches so to speak?
that's easy, you just need to fetch a bunch of momentary switches

I'm only stuck at the point on how to replace the expression pedals. Can't figure out how that LED+LDR circuit works. I'd understand it a bit mor if BLACK1 was after the LDR and not before.

anyone?

BTW. got a chassi for it today, just asked my father if he knew any companies that could bend metal. he just snatched the CAD drawing and fixed me one. great

Noumenon · April 23, 2005, 09:44:40 AM

Could it be this simple?

BTW. the LDR is a Phototransistor, but I fail to see the difference. hm.

chokeyou · April 24, 2005, 06:20:37 AM

here's something i suppose you can TRY (no guarantees)

get ahold of one of the expression pedal pcbs, remove/cut the 2 wires that are what the midi junk reads off of, but NOT the power/ground. break out the DMM and measure the resistance of the circuit as you go through sweep, then just find a pot that goes to the same value. if you cant read resistance off of it, chances are it cant be replaced with a pot.

Noumenon · April 24, 2005, 10:06:42 AM

Yeah, I'm gonna try that one.

However, I'm in doubt 'cause it's a phototransistor, like the one in this pic (T1 and T2:
http://home.arcor.de/harald.graef/schematics/IR-Empfaenger/ir_receiver.jpg

And from what I know, which isn't much, a transistor doesn't alter the resistance.

Noumenon · April 24, 2005, 01:15:14 PM

Damned memory.

The transistor alters the mA from A to B
How do one calculate what value a pot should have to alter the mA from A to B?

chokeyou · April 24, 2005, 04:00:33 PM

or, what about just adding a jack to the enclosure and using one of the behringer FCV100 exp pedals, i'll bet they're built the same electronically.

Noumenon · April 24, 2005, 05:25:14 PM

easy, I want an ernie

But a friend of mine has helped me.

All we need is to find a replacement for the phototransistor, a regular transistor, wire the jack to the base (250k pedal probobly) and if needed, some resistors before the base.

chokeyou · April 24, 2005, 06:05:13 PM

go for it. I'd like to see what you come up with and MAYBE a build tutorial? I'm about ready to jump into guitar synthing head first and need a midi controller to change programs in the nord lead rack i wanna get along with the roland RI-20 box. That link that was posted earlier is very interesting, and I think I'd rehouse it exactly like he plans to...but it seems he never actually started/finished it.

Noumenon · April 24, 2005, 06:12:52 PM

Yeah, however, I think his box is too big. Atleast too high.
If you want I could post a pic of the drawing I have of my case.

The anoying part now is the fact that the switches costs nearly a fortune *lol* Adn the display, it isn't easily removed.

chokeyou · April 24, 2005, 07:55:43 PM

well, the way he's going about it seems a little ridiculous, I'd be fine cutting up the existing black display panel, rounding the corners off, cutting a large hole in the enclosure and dropping it in. figuring out a way to punch those little rectangular holes would be a headache...not to mention if you get your spacing off you're kinda screwed.

Noumenon · April 24, 2005, 09:49:47 PM

yeah, but, how are you going to get that display piece of?
I'm clueless on how to do it.

anyway, my case:
http://212.112.183.111/IM1.png
the units is in mm.
----
did some probing today, it's 5v through the pedal circuit.
one thing that came in mind, why not just put the pot infront of the LED ?

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FCB1010 Mod