Hey guys well I finished my Dr. Boogey build and as per usual its not working right off the bat... :-\ Bypass works, when the effect is turned on via the footswitch it does nothing. No pops, no clicks, no whizzes or burrs. A couple of things that are different on mine...
1. I couldn't find the 680k resistor. I put 2 330k resistors in series in its place.
2. I couldn't find the any 22n poly film or ceramic caps at the electronics store. When I told the guy he offered me tantalums instead. So all 5 of the 22n caps are tantalums instead of poly/ceramic. I noticed after soldering them in that they have +'s on one side. Are tantalums polarized?
3. I read on the DIY FAQ that polarized caps can be used if the positive side of the cap goes to the side with the higher voltage. I dont have a multimeter and have no means of getting one for a couple weeks here, if this is true could someone post which ways to orient the 22n caps so I can get this build finished?
Thanks a lot.
Josh
EDIT: After reading about caps for about 2 minutes I think I found another problem. The store I use has all their caps listed in mf. I had to have the guy at the store help me convert the cap values from nf to mf so I could find the right ones. He told me that you move the decimal point one to the left so 22nf=2.2mf. After reading about caps on the DIY FAQ, I think I gather that 22nf=.022mf right?
QuoteAre tantalums polarized?
Yes, thats most likely why its not working. You need to use 22nf poly film, mkt, or ceramic caps im afraid.
Tants will work, just make sure the "+" side faces the Jfet Drain , where power connects from the trimpots
and the "-" side goes on to the next part of the circuit.
22n poly's are recommended though !
MM.
Quote--> I think I gather that 22nf=.022mf right?
That is very right. I always use this website thing here, saves me some thinking :) http://www.justradios.com/uFnFpF.html
It's a conversion chart, you might find it just as useful as I do :)
Hey by the way, mF usually means millifarad. for microfarad, most people use uF, because the u most resembles the greek letter 'mu' used for the micro prefix.
Anyways, good luck on getting your Dr. Boogey working! ;)
Ok, now I know why its not working.
For starters I just threw the tants in there with no particular polarity, not realizing they were polarized. Secondly, that damned fool at the electronics store had me calculating the values all wrong so every cap I used is the wrong value. He had me moving the decimal to the left 1 space instead of moving it over 3. So instead of having a .022uf cap, I have a 2.2uf cap in its place :icon_redface:
This is the part where I call myself a retard for buying completely the wrong parts, good thing I got a good deal ($2 for ALL the caps!)
Anyways, thanks a lot guys. Got to go buy the right parts tomorrow morning ;D
Quote from: MetalUpYerEye on August 28, 2006, 07:32:01 AM
He had me moving the decimal to the left 1 space instead of moving it over 3. So instead of having a .022uf cap, I have a 2.2uf cap in its place :icon_redface:
:D
That could sound erm ..... "Interesting" !!!
Keep all the tants for other projects, 2u2's etc will come in handy for bypass/coupling caps.
MM.
Give it time to gather a little more experience. Before long, you'll be able to calculate capacitor conversions in your head, and you'll realize that tantalums don't come in values as low as 22nF. :icon_smile:
Its not that i'm bad with math or anything, I just didn't know the conversion rate and the guy at the store had me converting them wrong.
Here's a handy Link from the guy that made your PCB. It's an online capacitance converter.
http://www.onlineconversion.com/electric_capacitance.htm