Kingslayer - weird power cycling loop of death

[Mike B.]

Hi all,

Just wondering if any has run across this. I just finished a Kingslayer build (buffered). It works fine in bypass mode (which tells me the buffer is probably okay). When engaged, it works fine for about 10 seconds, although none of the clipping modes seem to make a difference in sound. After 10 seconds or so it goes into a weird power cycling death loop where the power cuts in and out (LED flashes on and off as well). It gets faster if I let it go on. I checked for solder bridges, etc. and all is well. I've built literally 20 or more Klons with other PCB's and have never run into this. I'm using a TC1044SCPA for regulator.

Any ideas?

[Mike B.]

Wiring -

[jkokura]

I would bet you've got a solder bridge in your power section. What steps have you taken for debugging thus far?

Jacob

[midwayfair]

Dead power cap or zener, maybe? Does the gain knob do anything? Pretty dangerous situation to get voltages, though, for better troubleshooting. :/

[Mike B.]

A short makes sense - probably my power supply detecting the short, shutting off, powering back on, detecting the short again, etc. I'm puzzled why it didn't happen in "bypass" mode though, because the circuit is still "powered".

I'm in the process of removing everything from the enclosure. I'm usually very careful about visually inspecting the boards for solder bridges before I box everything, but that doesn't mean there isn't something too small to catch at a glance.

[Geosh]

Check your orientation C26 (and c25). It looks like C26 is backwards. They should be opposite directions but it looks like yours are the same way.

[Mike B.]

Yup! Good catch, thanks!

[Geosh]

No prob! I did the same thing with a tantulum cap on the first Klone build I did. 

[Om_Audio]

Nice, glad you all got it sorted.

You know, I was going to suggest an issue with a cap possibly just based on some breadboard experimenting I did last night where I sort of saw how caps charge or discharge rather slowly sometimes. Without going into all of that, could you explain what would be happening with a reversed cap?
C

PS- don't forget to post a top shot!

[oldhousescott]

Nothing to add, since you already got it sorted, but can I just say day-um, that's some nice work!

[Mike B.]

Thanks all, working great now. And, thanks for the compliment - I'm pretty OCD about my wiring. If only I'd been as careful with my component placement

Oh, and Jon - I used a pair of OA126's that I got in that batch from you a few months ago. I think they are now my favorite clipping diode!