So I completed my first pedal build the other day... a DOD 250 overdrive clone. Got the info from here
http://www.diystompboxes.com/smfforum/index.php?PHPSESSID=c96cafefb54bd008ed8aa6fc5cbdde2b&board=33.0 and here
http://gaussmarkov.net/wordpress/circuits/overdrive-250/
Appr. Costs (pedal specific):
mono jack (output) - R4
stereo jack (input) - R5
LM741 op amp and socket- R6.50
Resistors (10 pack) and diodes - R 15
LED (5) - R3.50
Caps - R10
Battery clip - R1.50
Pots - R24
knobs - R12.50
dc socket - R4
Metal Case - R96
3pdt footswitch - R90
Total - R272
Costs (reused for all pedals):
11mm drill bit for footswitch hole - R68
Breadboard - R51
Multi meter - R200
Solid core wire - R8.50
Ferric Chloride - R60
tungsten 1mm drill bit - R36 (RIP)
pc board blank - R15.50
So I started out building the circuit on the breadboard and just connecting the jacks, pots and 9V battery into the breadboard. First test into an amp and I picked up some random radio station when turning the pots... !!! haha :roflmao: Then I realised I left some jumper wires out, added those and lo and behold, the pedal worked! took me a while to realise the pots were wired the wrong way round, swapped that and it sounded way better!
Then I decided to take the plunge and do the circuit board and case etc. The circuit board is the easiest part, its the case and external components that takes the most time!
So i used a laser printer to print the pcb layout onto a piece of transparency, then ironed it onto the blank pc board. After a few tries I got the hang of it.
I touched up some places with permanent marker where the transfer wasn't 100%. Then it was to the acid! poured the acid into a small glass jar and suspended the pc board in the ferric chloride. Took around a 45 min to etch completely.
Drilling time! So I whipped out my newly aquired tungsten 1mm drill bit and started drilling with my hand drill (note: next on my tool list is a drill press). Needless to say the bit broke! R36 gone, just like that! ?
So had to wait a few days, then I bought 4 1mm normal steel bits. They work just as well.
Solder time... now I know why they refer to it as sniffing solder, you really do sniff it! ? soldering the components went way faster than I expected and was easier than I expected too!
Then it was off to the amp for another test. It worked!
Now it was case drilling and installation time! It ended up being really cramped in there, I was so excited to get everything in I didn't plan it to well. Well at least I know better for next time!
The case drilled very easily.
The wiring of the switch was quite a mission... LED & resistor, dc jack, battery snap, true bypass, input jack, output jack... it all got quite confusing! Tonepad has a great pdf called offboard wiring which helped loads.
And that was it! :woohoo: Many things were done more than once due to mess ups the first time, but I think it came out alright! I still think its not 100 % the same as the DOD original, it sounds too dirty, but haven't really played the original.
To Do:
- take a hacksaw to the pots, they look rediculous atm, to long!
- heat shrink all open wires/connections.
oh ya, and the sound... well, I initially said it won't make it on my pedal board as its got nothing on my current OD pedals, but last night I thought I'd hook it up with the Blackheart and ended up getting some really nice rough, dirty blues tones out of it. Sounded awesome to my ears. So currently it is my dirty blues pedal! hehe. (I generally don't play blues except at home, but I'm really getting into it now!)
Now I just have to get the pedal to be reliable as it cut out a few times while jamming (probably shorted out due to open connections) and also the LED has a delayed reaction when switching on sometimes.
