-Fits min 3 pedals + tuner
-Powered, without daisy chaining a crummy wallwart
-Integrated channel switch
-Spend the least amount of $$$ as possible
Powered pedalboards from powertrain or other companies sell for over $200 online, even an isolated supply can be over $200 on its own. Alot of the components for this were found around the house and the total price was around $80. The case is an old poker case, the channel selector/effects bypass and power supply are built from scratch with a switchable 12v/18v output and 4 isolated 9v outs.
The power supply portion of this project deals with mains supply (120v) voltages. If you have little electronics knowledge/experience DO NOT build the power supply, you will be working with voltages that can be lethal and if setup inappropriately can wreck your gear. You undertake this build at your own discretion and I will not be held liable for any injuries or damage to your gear.
With that out of the way, let's have some fun!
Step 1: Parts!
Some kind of latching box or board that you will be building on, many suitcases can be modified to work. I've used an old poker chip case, it is somewhat limiting in its size and depth (can't fit a wah or big EHX pedals in there) but it's compact, lightweight, and strong enough to keep everything in one place.
-Velcro (about 3-4ft)
The Control Center:
Mine consists of an fx loop (send/return), bypass and channel switch with an LED indicator:
-Project box (I used an old hot chocolate tin, cut to size)
-5 mono input jacks. FX Send, FX Return, Input, Output, Channel switch
**Some amps require a stereo TRS jack for channel switch, be sure to get the right circuit before wiring this up**
-2 DPDT switches (1 latching stomp and 1 toggle). Almost set it up with 1 stomps but it was too cluttered, and I don't have to bypass often.
-1 LED & 470ohm resistor for the channel indicator
** Check out Beavis Audio for a variety of looper/bypass schematics with indicators and mixer controls if you want to really do it up**
-18v transformer (300ma)
-4x 1N4001 diodes or 1x Bridge rectifier
-3x 100uf capacitors, +30v
-5x 10uf capacitors, +30v
-3x 1k ohm resistors (1/4 watt)
-1x 470ohm resistor for LED
-3x LM7809 voltage regulators
-1x LM317 voltage regulator (for a 12/18v output)
-2x SPDT toggle switches
-1x LED &Bezel
-1x 120v 3prong power input
-1x 100ma fuse (used a resetting 'pico' fuse from small bear)
-various nuts and bolts to mount the transformer and power input
-DC power cables for the power cable runs (ebay)
-1/4" hookup jacks for the cable runs (ebay)
**Special thanks to matthegamer463 for the schematic and design influence**
-Drill w/ various bits (Biggest I have is 1/4", something bigger would be helpful)
-Dremmel or rotary tool (especially if you don't have anything bigger than 1/4" drill bit)
-small/med size grinding stone
-Wrenches, adjustable is best
-Soldering iron (solder, hookup wire etc)
Step 2: Bring the Power!
Prepping the enclosure:
FIGURE OUT HOW MUCH SPACE YOU NEED! <-- you don't want to get to the end to find out you haven't organized the box properly and certain things won't fit. Start by laying out the transformer and supply input to find out where they can feasibly fit and plan how to organize the switches, circuit and the rest of the components around them. Once you have a general idea, begin building the circuit or at least plan it on the board so you know how much space it will take up. I needed to cut my enclosure down as it was too tall for the poker case. Luckily it is plastic, unfortunately I'm rubbish with a hack saw so the job was pretty shoddy. I used a grinding stone and dremel after to even out some of the more warped areas.
Circuit works like this:
-Power from wall goes through the switch and fuse to the primary (black) side of the transformer.
-18v ac output (mine actually measured about 21v ac) goes to the bridge rectifier.
-Rectifier converts AC to DC
-100uf filter caps help smooth any DC ripples
-Regulators take the approx 25v DC down to the chosen voltage and provide a constant output regardless of the load.
I used this schematic from matt as it used the same transformer I had.
The rectifier and filter is the same as the schematic but I included an LM317 variable voltage regulator with a switch. I wanted to have one output switchable from 12 to 18 volts, you may want it different, this LM317 calculator helps to figure out what resistances you'll need. In my case it was a 220ohm between vout and adj pins, then on the adj pin wire 2kohm (used 2x1k in series) to a switch that goes straight to ground in one path or adds another 1kohm in the other path to produce the 18v required for my 10band EQ pedal.
Building the circuit it easiest with stripboard, but since i only had perfboard I made the connections by soldering components to each other to to common wire bridges. I'm somewhat of an amateur when it comes to layout with perf board but i think i did a decent job.
To maximize space I put the BR/filter cap section on one board which fit right next to the transformer, and the voltage regulators on another board.
You'll notice that there are 5 DC outputs and only 4 voltage regulators. The last 709 powers 2 jacks in parallel, this was done to save space and because I only had 3 709s. Most guitar pedals have a minimal current draw (10-20ma) so two in parallel likely won't require the total 100ma output.
However, like the EHX holy grail which advises a 500ma adapter, some pedals require more than 100ma each regulator can safely provide, check the spec sheet if you are unsure but as a rule of thumb if it takes a battery it likely won't draw anywhere close to 100ma. I can't fit the holy grail in this box anyway so it's not a problem for me ;)
Tooling the enclosure:
Now that you're confident everything is fitting in the box wrap it up with masking tap to mark it for drilling. I made most of the marks by hand, using a ruler to ensure the holes for the dc jacks were level. Drill pilot holes for all switches, jacks and mounting screws and then size up the holes as necessary.
Mount the transformer and power input and wire up the switches and mount them as well leaving more lead than you think you need (can always cut it down later).
**Be careful soldering small switches. I ruined 1 by leaving the heat on too long and one of solder tags melted out of place making it garbage. Luckily i had a few more on hand. If you don't have too much experience with soldering/ circuit building then always get 2 (or more) of each component, chances are you'll use them later in another project.
Wire the transformer to the power input. Since I'm using a plastic enclosure I've ignored the ground, ***OTHERWISE BE SURE TO GROUND THE ENCLOSURE IF USING A METAL BOX*** Wire in the fuse and circuit boards and begin testing.
Do a check to make sure all AC leads are properly soldered and insulated, plug it in and turn on the power. Now use a volt meter to test that each regulator has the proper output voltage. If everything reads nicely then start wiring the DC outputs. Remember that most guitar pedals use a negative center and positive barrel , wire one up and test the output to ensure it is the correct polarity before soldering.
Step 3: Control Center
Schematic for the channel switch was grabbed from Orangeamp forum (copied the guts someone posted from the actual orange footswitch) and the bypass/looper comes from Beavis Audio <--Great resource for any musical DIY'er.
The purpose of this "control center" is to run the input through an effects loop or bypass the loop and send the signal straight to the amplifier, and also for channel switching between the 2 amp channels on my Orange Dual Terror amp. The point of the bypass is that sometimes certain pedals, even if labeled "true bypass" can 'suck' tone from your signal and I wanted to have the option of being able to go direct guitar-to-amp with the flick of a switch. I used a toggle for the bypass because 2 stomp switches would have been cluttered and the only other one I had is 10$ 3P3T that I did not want to waste on this crude but effective device.
The case was a tin of hot chocolate mix which was cut with a dremel to fit neatly in the corner of the box. Once cut and 'deburred' I wrapped the whole thing in gorilla tape, mostly for appearances, but it does cover some of the sharp metal edges and enhances the structural integrity.
Once everything was wired up many of the connections (particularly the output) were epoxied to ensure nothing shorted in this very cramped enclosure. Output jack and LED also held in with epoxy. The flimsy tin is kept rigid by gluing in a steel mounting bracket (wrapped in tape to ensure it doesn't short against any connectors) that was left over from some ikea shelves. To further improve the structural integrity, 2 chopsticks from last night's sushi dinner were cut to size and epoxied in horizontally to support the frame.
Be sure to test it before making any permanent alterations (like the epoxy support barrage). Make sure your channel switch and loop are doing their job and there is no extra noise or erratic behavior, I had a couple shorts from close contacts that were remedied with... you guessed it, epoxy.
If I were to do this again I would probably just get an appropriately size project box, but as much as this was hacked together from whatever I had on hand it fits in nicely and does it's job perfectly.
Step 4: The Board
First the top had to be removable. When the box is closed make a mark on the hinges that move with the top part of the box. Draw a line about halfway and use a dremel to cut the hinges. Taadaa!
Did a quick layout of my pedal configuration and applied velcro accordingly.
I cut out a section of the metal frame which allowed me to remove the side panel all together for easier tooling. I originally planned to have the power outlet flush with the outside of the box but when mounting it had to be inset slightly because of a protruding bolt holding the transformer mount.
The input and channel switch jacks for the control center are mounted directly to the side panel and the wall power outlet must be exposed as well. If you build the control center first, be sure your holes lineup with a slightly bigger hole in the panel to ensure easy mounting.
After cutting the space for the power outlet and jacks I painted the panel black (mostly to coverup markings for the holes but it looks cool too!) and reinserted it with epoxy to hold everything down tight. Jacks took some fiddling to fit in (as you can see from the chipped paint in the pictures). Used a sharpie to touch up afterwards.
I mounted the power supply directly to the board using the baseplate included with the enclosure as a buffer and template to mark the drill holes. Used tape to prevent contact from any of the electronics.
Also epoxied each of the corner seams for some added support
Step 5: Final Thoughts
The power supply is noise free and has been running great. I may do a check to make sure my regulators aren't creating too much heat, possibly burning insulation from adjacent wiring, in which case I'll add a few "speed holes" for ventilation.
I found some right angle dc power cables on ebay and made a few custom length power runs ($6 for 10 'ends', made 5 cables). Also got some right angle 1/4" jacks ($12 for 10, made 5 cables) and using a broken old fender instrument cable I made some custom patches. Really cleaned up the whole setup and left alot more space, things aren't so cramped.
I'm going to add some kind of clip or strap on the outside top of the box that will hold the power and in/out cables when traveling.
Replacing the latches with a padlock-able one.
Replacing the handle with something a bit more robust. The poker set was quite heavy so I'm not too concerned about the support of the box, but in a situation like this there are plenty of room for upgrades, and plenty of money saved from not spending the $300+ dollars on a powered board and flight case.
I realize I compressed a pretty big build into just a few steps (still new to this instructable thing), if you want clarification on anything leave a comment, that way others can get an answer too.
Good luck and happy building DIY'ers!