SOLVED Cobalt Drive problems…..SOLVED……..FINALLY!

Jeff C

Active member
New member here and also new to building pedals, as you will shortly see. I previously built a BYOC Reverb pedal kit successfully and it sounds great. I’ve also built from scratch a Strat, a Tele, a 59 LP, and an LP Junior. So, I wanted a blues driver pedal and thought I’d take a whack at the Cobalt Drive from PedalPCB. The directions are not as detailed as in a kit so I’ve had some difficulty. Clearly in over my head. I managed to procure the parts from the list (not without trial and error on my part) from Tayda. I mistakenly bought a switch without solder lugs so after consulting a patient, helpful friend, bought a daughter board and did my best to figure out how to marry the two - having no skills whatsoever in electronics. History major. I have managed to assemble it but I get nothing from it except static pops when I plug it in. Bypass doesn’t work. No idea what I’ve done wrong but I suspect it revolves around needing to do more with the daughter board on the switch. But what do I know? Here’s a couple of pics (the power jack is not there but I did connect it to test). And I haven’t installed the LED yet. Any and all suggestions are eagerly welcomed. You may recomemd I should just start over but I hope not….. Thank you!
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Well, i put a bridge on the D100. No solder, it will adhere to the bridge but not the diode pins. 🙁. But I do get connectivity between both sides, and now when I test the voltage I get 1.2v on both sides of the diode.
 
You should get about 9V on one side of the diode and about 0.6V less on the other. You are getting substantially less than that so either you have a short somewhere or the diode is busted (although in that case I would not expect a fixed 1.2V like you’re getting, but either floating voltage or 0).
 
stand by. My power jack is acting weird. I get 9v on the positive pin, but when I connect It to the wire leading to the PCB, it drops to 1.2v. (it didn’t do that before……) I’ve not soldered it because I have to install it in the enclosure before I can solder it and it will be impossible to troubleshoot this dang thing that way. I guess I‘ll solder it and see if I can get the 9v back……..and then just take the wires off and resolder if I ever get this thing to work……
 
Now completely befuddled. Soldered the jack. Still only get 1.2v! Tested i both at the jack and the PCB. The jack is ok because I tested it without the wires connected, prior to soldering. 9v. Then soldered the wires and tested it at the very place where I soldered on the wires and it’s now 1.2v. How can the jack test lower just because I soldered the wires to it? Aaaarrrggghh.
 
Now completely befuddled. Soldered the jack. Still only get 1.2v! Tested i both at the jack and the PCB. The jack is ok because I tested it without the wires connected, prior to soldering. 9v. Then soldered the wires and tested it at the very place where I soldered on the wires and it’s now 1.2v. How can the jack test lower just because I soldered the wires to it? Aaaarrrggghh.
Hard to say. You may have a short somewhere between the power supply and your test point?
 
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