Hi Guys

I have given up finding an FSB104 footswitch for a Bugera 333xl head, so I guess I'll have to build one - with some help please.

The FSB104 is a 4-button device connected with a 7-pin DIN plug. It switches Clean, Crunch and Lead channels and the FX loop. It has LED indicators, which are not necessary, hopefully dumping them might mean I can use simpler switches with fewer poles - or something.

Can anyone help please?
Thank you
Found this:
May or may not help you.

Couldn't find shit otherwise

Ask in this thread.
Maybe you can get some info/pics/schematics there.
Last edited by CodeMonk at May 31, 2014,
The guys on highlyliquid are trying to make a MIDI pedal, but I'll post on the UG site and see what happens

Sorry for resurrecting this post but UG won't let me create any....

I own a Roland Cube 80gx wich I paid €300 here in Europe... but they would charge me €100 for the ga-fc footswitch.

So has anyone come up with schematics for this?
I could make an fs-6 but I'd like to activate/deactivate efx,rev, and delay too

Thank you in advance!
How good are you with electronics?

A google for FSB104 gave me a link to an old Bugera PCB schematic for their digital module - http://music-electronics-forum.com/attachments/24583d1375837664-bdm1-bugera-333-xl.pdf
It shows the internal components that connect to a 5-pin connector.

Now looking at that, there are 3 inputs that need to be switched to GND to activate the relative channels, along with one that gets fed to an ADC pin for the FX-loop. Now for the 7-pin connector, I'm going to guess they simply added a 5V feed, and possibly never connected the extra pin, or it's maybe an additional earth.

If you can identify the GND pin, you should be able to work out the other pins using a multimeter and a 22 ohm resistor. In turn, connect the 22ohm resistor between each pin and the GND pin, measuring the voltage at the pin you're testing. The basic switching inputs, the voltage should drop from 5V to 2.5V, any additional 5V supply should stay at 5V, and the analog/FX input should drop to near 0V.
Off course, that's assuming they're still using a Atmel Mega chip for the interfacing, but they may of moved to something that only uses 3.3V for the inputs.

Once you figure out what each pin does, I'm sure you can figure out how to add LEDs into the mix.
Actually, it would appear there are different versions. Just found a pedal schematic at http://fr.audiofanzine.com/pedalier-controleur/bugera/fsb104/forums/t.511089,recherche-schema-electrique-du-footswitch-fsb104-pour-bugera333,p.2.html
And that wouldn't work with the above schematic.

A quick look over that schematic, and it would appear the switches work via a resistor ladder

Just realised how they're doing it having looked at the schematic more!
All the switches are connected to the ADC pin (X4 on the hand drawn schematic), and all the switches use a resistor ladder type approach, so each switch generates a different voltage at the ADC.
The LEDs are then controlled via the three other connections (Mega pins can be configured as inputs or outputs). I'm too tired to fully understand the hand drawn schematic, however it looks like two LEDs are controlled by changing the polarity of two pins (X1/2).
X5 is GND, with another LED controlled via X3, and the final LED via X2 and the transistor (I'm guessing they maybe apply a PWM to the pin so the transistor/LED get switched on without causing any of the other LEDs on X2 to illuminate)
I just wanna post these pin diagrams so that people can convert newer footswitches to older amps and vice versa. I made these when converting my newer footswitch to my older 6262, but also worked on a friend's amp. He had a newer 6260 Infintium, but had the older footswitch.