Am I the only one.....(Easyvibe content)

[Bucksears]

...having problems with my Easyvibe's 100uF cap at the 9v rail heating up to the point of expansion/explosion? I have built this thing four times now (two different boards) and gone over everything. This is the only pedal that I've ever built that did not work correctly. I hate to hang it up, but I'm getting tired of spending so much time on this one circuit.

Here's what I know:
I'm using a 16v 100uF cap for C9 (the cap that's heating up)
My LEDs and diodes are oriented correctly
I'm using a 9V wall-wart (Ibanez AC109), (+) to board, (-) to ground
There are no solder bridges at all

I'm not going to rebuild it again (or start on a Neovibe), so if this doesn't start working, I'm going to a commercial one.
I just can't believe that this isn't happening to others.

[snoof]

are you sure that the wallwart is working properly, whats the actual voltage it's putting out??  Have you tried a new 100u cap??  Have you tried a diff wallwart or a batt?? Are the diode and LED's in the bias section oriented properly??

[R.G.]

Caps heat up because there's too much current through them. Period.

That can happen three ways. (a) the cap is backwards and flowing current like a forward biased diode or (b) the cap is being fed too much ripple current; the voltage variation on the cap is too large, and that lets too much current flow by Iac = Vac/Xc or ( c ) the cap is old and leaky, and just can't hold off the voltage.

[Bucksears]

Just to be clear:
Using this layout (http://www.geofex.com/PCB_layouts/Layouts/easyvibe.pdf), shouldn't the cap be oriented with the (+) facing the 9V input?

I'm using a 16v 470uF cap; maybe I should try a 35v? I'll measure the voltage at the DC jack this weekend.
Thanks guys,
- Buck

[Bucksears]

Ok. After measuring the voltage at the connections on the back of the DC jack, it came out at 8.9v.
Now the cap is just BARELY warm, but everything works fine. It works with both the single wall wart and the daisy chain (Godlyke powerall).
Can't explain it since I didn't change anything. I'm going to take it as a happy coincidence/miracle and keep going.