Ch0jin
October 24th, 2010, 06:29 PM
Well I just had a major /headesk moment that I'll share in the hope it saves someone the hassle of doing it themselves...
I always HATED those plastic DC jacks you get with FX kits, (I've melted a couple, which is mostly why I hate them) so when I found some solid looking Metal (http://www.jaycar.com.au/productView.asp?ID=PS0522&keywords=2.1mm&form=KEYWORD) ones at my local, I was all excited. Solid construction - tick, nut on the OUTSIDE - tick.
Fast forward a few months (i got sidetracked) and I'm troubleshooting intermittent power to the finished pedal when using external DC.
The clearance from the DC jack to one of the pots is tight so I tape off the pot, file the socket hole a little and remount the socket another 2mm away figuring I have a short (wiggle the plug and the power cuts in and out). Reassemble and test and now NO power when external DC is plugged in.
Hands up if you have figured it out yet?
Yup. A BOSS 9V brick is tip negative and shield positive, and when you plug that into a metal socket mounted in a painted aluminium enclosure, it's only the paint preventing a direct short, hence why the wiggling caused it to be intermittent, and when I took to it with a file, removing the insulating paint, it was a dead short.
It's humiliating to admit that after doing everything from building the circuit on vero to painting and drilling the enclosure myself, that'd I'd make that mistake. Although to be fair to myself, my last non-kit builds were vero Ge Fuzz's that have no DC socket...
I guess NOW I know why GGG and BYOC include those plastic jacks after all :)
Anyway. Beware the metal jack fellow box builders!
I might go see if i can jury rig a solution with heat shrink so I can finish this off without major surgery to accommodate a plastic DC jack (that I'd have to order in)
Oh and as you'll likely see when I finish it up and photograph it, it's actually an OCD Ver 4 on vero in a large box with selected caps and transistors socketed for experimentation...
I always HATED those plastic DC jacks you get with FX kits, (I've melted a couple, which is mostly why I hate them) so when I found some solid looking Metal (http://www.jaycar.com.au/productView.asp?ID=PS0522&keywords=2.1mm&form=KEYWORD) ones at my local, I was all excited. Solid construction - tick, nut on the OUTSIDE - tick.
Fast forward a few months (i got sidetracked) and I'm troubleshooting intermittent power to the finished pedal when using external DC.
The clearance from the DC jack to one of the pots is tight so I tape off the pot, file the socket hole a little and remount the socket another 2mm away figuring I have a short (wiggle the plug and the power cuts in and out). Reassemble and test and now NO power when external DC is plugged in.
Hands up if you have figured it out yet?
Yup. A BOSS 9V brick is tip negative and shield positive, and when you plug that into a metal socket mounted in a painted aluminium enclosure, it's only the paint preventing a direct short, hence why the wiggling caused it to be intermittent, and when I took to it with a file, removing the insulating paint, it was a dead short.
It's humiliating to admit that after doing everything from building the circuit on vero to painting and drilling the enclosure myself, that'd I'd make that mistake. Although to be fair to myself, my last non-kit builds were vero Ge Fuzz's that have no DC socket...
I guess NOW I know why GGG and BYOC include those plastic jacks after all :)
Anyway. Beware the metal jack fellow box builders!
I might go see if i can jury rig a solution with heat shrink so I can finish this off without major surgery to accommodate a plastic DC jack (that I'd have to order in)
Oh and as you'll likely see when I finish it up and photograph it, it's actually an OCD Ver 4 on vero in a large box with selected caps and transistors socketed for experimentation...