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Oh man, I broke my class D amp. Make fun of me. Then help.

So... I made a new pair of super fancy interconnects this evening. Of course I was on auto pilot on the second one, especially the last connector. And, of course I always test my DIY cable projects before install..

Except tonight. Installed the ICs and all I hear is clicking. Not loud, and independent of the volume on the pre. Independent of source. Weird. I shut everything down and figure maybe, for the first time ever, I miswired a cable, so I pulled the new ICs and tested. Sure enough, I crossed my signal and ground. I repaired my mistake, reinstalled and now the amp the crossed IC went to is jacked.

The volume is much lower than the other channel, there is distortion during strong high frequency signals and the sound drops out during strong low frequencies signals. The other amp is fine. I swapped channels coming from the pre and the problem stayed with the amp. I doubt it is the speaker, as there were no sudden loud noises. Just the innocuous clicking...

So, what did I fry? Some kind of capacitor? Or everything? The amp is a Ghent audio monoblock, which is class D and uses ICEpower a/s modules. It is a GA-M500. Here’s its webpage: https://www.ghentaudio.com/amp/ga-m500p.html

I’m fine sending it in for repair, but if anyone has either knowledge of amp design or the unfortunate luck to have done this, I’d love to just fix it myself and save a lot of sending it around the world. Also, feel free to make fun of me. I deserve it. Such are the consequences of hubris.

If you’re wondering, I used KLEI pure harmony connectors, which have two identical looking tabs, one on each side, to solder the signal and ground to. If you look even remotely closely you can easily tell which is the ground.. but it’s not at bad as if I had done this with a more traditional RCA connector. That would have been really pathetic. 

Also. Recommendations for repair shops please.

Ugh.

128x128toddverrone
kdude66
1,198 posts
 
Oh my,
The advice in trouble shooting a class d Amp just blows my mind.
toddverrone's avatar
toddverrone OP
838 posts
 
Wow, thanks everyone. Good to know I’m not alone! Yesterday I did the best thing one can do after screwing up royally: I took my kids and their friends to a beautiful Ozark swimming hole and we spent 9 hours basking in beauty and playing in a waterfall.. ahhh.

@atmasphere I did try different Interconnects ​and had the same problem. I’m sure the one I built is good now. I fixed the switched connection and TESTED THE DAMNED THING FOR CONTINUITY!

@spatialking I don’t see why a weak voltage like a signal would screw anything up, but it has. Like I said above, I tried other sources and different cables, moved the amp.. it’s the amp for sure. And man, yeah, shorting an amp in that fashion seems much more exciting and dramatic!

@asvjerry those poor fish...

Greg - the clicking was only there when I had the faulty IC connected. Then it just sounded like garbage and eventually stopped working most of the time. The problem I have is that the B&O module used in my amps isn’t made anymore. The only one I’ve seen is on eBay for $900!

On a positive note, my wife, the breadwinner, just said "buy some new ones". Also, a friend who works with class D amps in an industrial setting told me that he and his electronics guy could fix it. I was dubious, but he’s insistent, so we’ll see.

And, to and a big fat twist, I came home from the climbing gym last night to find my wife still awake, looking through my eldest son’s phone. She found all kinds of interactions with racist, white supremacist scum on social media and some porn. It’s going to be a long summer.. and it definitely put a broken amp into perspective, in terms of the crap I’m going to have to fix.. teenagers. Jeez.



atmasphere's avatar
atmasphere
7,068 posts
 
@toddverrone, OK- the next thing is to swap the interconnects left for right at the input of the amps.

You want to make sure that its not the source that got blown up, and FWIW its output got shorted to ground with that initial mis-wire.

So if you do that swap and nothing happens then the amp somehow failed (could be a blown fuse BTW).

But if the problem moves then the amp is off the hook and the source needs to be examined.

Good Luck! - on all fronts!
asvjerry's avatar
asvjerry
609 posts
 
Yeah, a 'downer', fitting the Monday mold....BUT....

Spouse announced she's going to carry on with her hobby.  Made my day.  Feces occurs, so scrape it up and fling it @ fates' face....*growl*L*

You do so too.  Let your buddy's buddy take a crack at it.  Let someone who has some experience with the D's give it a go.  He'll either find the problem or pronounce it truly screwed.

Suggestion #2:  Get spouse favorite flowers, apply huge hug and kiss, and another thank you.  They don't make a lot like her, and she's Yours. *S*

Elder son & porn....well, it's the most popular thing on the 'net, and curiosity overcomes 'no' because it did with us.

The racist white super sh*t is harder.  Take him on a drive through any local ghetto (most cities have something like that) and ask him if he'd like to go for a walk....home, from there.  There but for (your favorite deity) and the luck of being your son goes him, and their reality still isn't pretty despite the broken promises and hopes of intelligent people.  That latter group is aware that the bulk of the people on welfare and food stamps are white, and generally single women with children who are in that state because of guys who take advantage of them and split.
If there's anything he should learn to hate, it's the rampant stupidity on those websites.  

toddverrone's avatar
toddverrone OP
838 posts
 
Jerry - that's good to hear. Your wife sounds like a good one too. Patience and understanding in a marriage are rare, one thing I love about the people on here is they recognize that. I've been on far too many forums where there's plenty of denigration of spouses who get in the way of the hobby. That's the wrong perspective.

As for the porn, I'm not worried about that, but we did talk about the difference between 'healthy' porn, where it looks like everyone is enjoying themselves, are not drugged and have real bodies, vs the rest. The racist stuff comes from us living in a bubble here in NW Arkansas, where he doesn't see its consequences. So he thinks it's absurd and funny. Now I've got him reading Roots. That should help bring some perspective..

@atmasphere I think I tried different sources, but now I can't remember. I'll try again after I put the amp back together. Thanks for the insights!
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