Harbinger One - I nuked it w/ AC 24v. Now it warbles/squeals at speed value.

Started by Miles, September 20, 2020, 07:28:29 PM

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Scruffie

Ohhh, I was looking at the wrong one... So it does have a series protection diode.

Well, my advice either way is the same, try replacing the regulator.
Works at Lectric-FX

Miles

I previously had checked the LM7815 and the values I was reading were consistent with the documentation and advice provided in this thread. I want to make sure it's still a good idea to swap it out or if there was something else I should be looking for.

jimilee

Quote from: Miles on September 22, 2020, 10:44:17 PM
I previously had checked the LM7815 and the values I was reading were consistent with the documentation and advice provided in this thread. I want to make sure it's still a good idea to swap it out or if there was something else I should be looking for.
You can't break it at this point, I don't see why not.


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Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.

Miles


Miles


Scruffie

Darn, at least you know the power supply is all clean now.

Next step will be to audio probe through the circuit to try and pin point what took a hit.
Works at Lectric-FX

midwayfair

Quote from: Scruffie on September 21, 2020, 07:34:44 PM
It's very likely just one of the electro's in the power section, the parallel protection diodes aren't as fool proof as series. You nuked it with DC (if it was AC, I'd tell you to bin it and start over) but of the wrong polarity (also those supplies are unloaded so can be higher voltage than stated) so whatever the electro next in line to the protection diode, replace it and then the next etc.

^ It's this almost for certain, there is an electrolytic SOMEWHERE in a power rail that was blown. What you've described is textbook power rail squeal.

It could be any of C19-C22 or C30-C32, and if it was, then the squeal should be everywhere in the circuit (though it might be louder as you go through).

Miles

In fact, there is squeal everywhere in the circuit. I started by replacing C1 assuming that's where the squeal began, and then was confronted with the same squeal. I am actively looking into this. Thanks for the heads up.

Miles

One thing I noticed is that there are no electrolytic capacitors (or any for that matter) from C19-C21. Only C22. Just confirming the others mentioned apply to the 2015 model. I have them on order now.

midwayfair

Quote from: Miles on September 25, 2020, 09:00:20 PM
One thing I noticed is that there are no electrolytic capacitors (or any for that matter) from C19-C21. Only C22. Just confirming the others mentioned apply to the 2015 model. I have them on order now.

Post a link to the schematic you're building from. There's at least two PDFs of the harbinger.

Scruffie

Quote from: midwayfair on September 26, 2020, 04:19:05 AM
Quote from: Miles on September 25, 2020, 09:00:20 PM
One thing I noticed is that there are no electrolytic capacitors (or any for that matter) from C19-C21. Only C22. Just confirming the others mentioned apply to the 2015 model. I have them on order now.

Post a link to the schematic you're building from. There's at least two PDFs of the harbinger.

He did  :)

Quote from: Miles on September 22, 2020, 11:45:22 AM
It's in the 2015 subfolder in the zip archive:

https://www.madbeanpedals.com/projects/archives/FilterMod/HarbingerOne.zip


Works at Lectric-FX

Miles

Everything squeals starting from the first component. I really don't want to chuck this in the bin, but am I out of options here?

Stomptown


Miles


jimilee

Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.