Calling mark hammer and anyone else wanting to post

[Ansil]

my buddy brought in a  nice ibanez cs-505 today.. he tells me that at some point with batteries it gave him a nice saw wave humm.  then he bought an adaptor because the bottom plate says AC adaptor use AC118.  unfortuneately for him he reluctantly bought an adaptor but didnt' read the fine print..  DC18V.            so he got some smoke from an
18/24v  1A power supply.. now nothing appears to be burned but i was wondering. with problems before and 1A of AC INTO IT.. hmm is it worth looking at.  and does anyone have a scheme i must have missed it.

[Mark Hammer]

Step 1, if it wasn't a "standard recommended" adaptor, what was the polarity on the plug?  If something needs to be able to use batteries, then it is almost 98% true that it will use the outside = +, inner contact = gnd convention for adaptors.  IF, however, it doesn't anticipate using batteries and doesn't need to switch from battery to adaptor, it can use whatever the hell polarity it wants.  Outside can be positive OR negative.  This mena that a large porportion of second-party adaptors will be the wrong polarity for pedals, and it is why companies recommend using THEIR adaptors, because they know someone somewhere will be naive about this reality and screw things up.

If your buddy's adaptor was polarity reversed, there is a reasonable chance that some of the chips will be smoked internally.

[Skreddy]

Also possible that just the polarity-protection diode is fried and the rest is ok.

[smoguzbenjamin]

Wishfull thinking, Skreddy. As Mark said you might need to replace all those chips. But no bad thing, put sockets in there and you can muck around with what sounds cool (or not)

[RDV]

I own a CS-505 & the adaptor. It's a 18v DC adaptor, the same as two batteries, it ain't AC.

RDV

[Ansil]

yep i konw i can't belive he thought it was ac..  this guy can open up his own stuff and clean the pots basic general maintenance.  fairly intelligent guy i guess he had  abrain fart.i checked the protection diode and yeah i was expecting it to be blown but its actually still working.. but there is some melted solder on further inspection and i think that some of the board is fried.. not worth my repair time

anyone know of a good diy capacitor site.  i was looking to make a 6volt 50farad or so cap. i used to have a good site to make hydraulic oil filled cylinders for massive high voltage homemade caps but lost it when the computer crahsed.

[zachary vex]

...

anyone know of a good diy capacitor site.  i was looking to make a 6volt 50farad or so cap. i used to have a good site to make hydraulic oil filled cylinders for massive high voltage homemade caps but lost it when the computer crahsed.

man, that's a lot of foil rolling.  good luck.  you  might just investigate getting a supercapacitor.  here's a 50 Farad 2.5V cap.

http://www.mouser.com/?No=10&D=*supercapacitor*&handler=data.listcategory&Ntt=*supercapacitor*&terms=supercapacitor&Dk=1&crc=true&N=0&Ns=MfgrPartNumber%7c%7cSField

[Mike Burgundy]

50F in a 40mm case? Damn... That's a LOT of capacitance!
I always thought this looked like something the powercompany used, not something you could actually see on a pcb. Wow.
Hmmm...building your own caps...next step is making our own semiconductors, MOSFETs, then we rule the world

[brett]

What's with "We will rule the world?"
I ain't giving it up so easy!! :wink:

[smoguzbenjamin]

You could get a 50 farad 7.5v cap by taking 9 50F 2.5v caps and arranging them 3x3, 3 sets of three caps in series. That might do the trick.

[Peter Snowberg]

You could get a 50 farad 7.5v cap by taking 9 50F 2.5v caps and arranging them 3x3, 3 sets of three caps in series. That might do the trick.

...with only 2.5 volts of roiom to work with, you might have balancing issues here. That can be lessened to the point of workable by adding resistors in parallel just like you see in tube amps.

Factoid: If you use two plates spaced 1/4 inch apart, it takes 6 square miles of these plates to reach one farad.  :shock:

I think that last on is correct, it was a long time ago that I heard it.

[Ansil]

hmm interesting peter i like that.   theres a great site there that is how to make oil filter caps. but i can't find it.

[dr]

...I still remember in school where our science teacher would show us how to make resistors by writing on pieces of paper with pencil lead; making capacitors with wax paper and foil;and diodes with a razor blade and pencil lead......wish I had paid more attention to it at the time.....I'm still working on a wind-up powered pedal....(I paid attention that day,but not very well)