Wanted to share my experience and knowledge about my DC power modification of the Behringer FCB1010.
If you didn't know, the FCB1010 is powered off the shelf by AC. This sucks. I still have a power supply on my pedal board with extra DC outputs, so I set out to power the FCB1010 via DC.
Things I learned about opening it up that may help you if you want to power your FCB1010 with DC:
- AC power from the wall is transformed to about 9.8 volts and goes through the yellow wires soldered to the PCB. The current draw through the yellow wires is less than 200 mA
- These yellow wires go through a bridge rectifier, rectifying AC power to approximately 11.5 V
- This now rectified DC power travels to a 7805 Voltage Regulator. Left terminal of the regulator is input, middle is ground, right it output. The output voltage is about 5V --> my guess is this is the working voltage within all of the integrated circuits.
What I did:
- Drilled a hole in FCB1010's cabinet to accept the DC power terminal jack
- Soldered the positive (hot) cable of the DC power terminal wire to the output of the bridge rectifier
- Soldered the negative (ground) cable of the DC power terminal wire to ground.
- Adjusted my power supply to output 11.5 volts
- Plugged in and voila!!!
Lessons learned (because I'm a n00b, though I am an engineer (mechanical)):
- For a non-permanent mod, you don't need to snip the yellow, transformed AC power input wires
- What adapter plug polarity is. For guitar pedals and guitar pedal power supplies (like my MXR iso-brick), the "hot" part of the plug is on the outside, and ground is on the inner terminal. This can be a problem when modding your 1010 unless you choose the right female DC jack to attach to your FCB1010 cabinet. I used the UNO4Kemper jack, which is metal, and here's the problem you may run into if you use this: After connecting your pedal power supply (like the MXR iso brick) into the Uno4kemper dc jack, the outer, threaded part of this jack becomes "hot." When you put this jack through the side of your metal FCB enclosure and tighten the jack down to the cabinet with the supplied nut and washer, you will ground out all of your power supply's output to your FCB1010 cabinet. So, you need either insulate the hole that you drill, or get an insulated DC jack to affix to your FCB1010. Also, uno4kemper's instructions have you connect both the positive and negative wires of the jack to both input diodes on the rectifier. This doesn't make sense to me. What makes sense is that you put the hot DC lead in line with the DC rail, and you put the other wire/lead onto ground. I chose the ground that is on the rectifier because I can solder it there. FYI the whole FCB1010 cabinet is the same ground as the integrated circuits' ground.
Cables I was running to the pedal board before (All the plugged in cables I was running included):
- Guitar cable from pedals to amp
- AC power cord to FCB1010
- DC power from wall wart to the MXR ISO Brick
- MIDI in and out cables
ONE CABLE!! ...PedalSnake from the back! The snake is carrying the guitar signal from pedals to the amp, DC power for MXR ISO Brick (from my power strip back with my Kemper head and powered speaker), Midi send, Midi return.