2. amps-preamps
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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
gregkohanmim
153 posts
 
Todd - I'm sorry about the family stuff and I couldn't possible help there but if:

"my wife, the breadwinner, just said "buy some new ones"" - I can guarantee you that I'd have a UPS tracking number within 5 minutes (and I love my setup)!

At least on that front, you're in good hands!

Greg
asvjerry's avatar
asvjerry
609 posts
 
Todd...yeah, after 30+ years, she isn't perfect but she deals with my flaws and foibles too.  There are those that didn't understand us, but we've outlasted them all.  And the long haul is the one that counts....;)

And you took the young bull by the horns....Bravo.  There is 'fair porn', but it's rare.  The material aimed at the female audience has a better 'tilt' to it, but most men don't even know it exists...and most could care less.  It'd surprise them if they paid some attention to it.  The soft touch generally goes over better, but that's an 'advanced concept' when you're young. *S*

NWAR...by the Ozarks...pretty country...and some reactionary minds, freaked by 'change'.  He's right, absurd is correct.....funny, not so much.
Watch '10 Years a Slave' with him.  That'll drain the humor out of it....;)

Pardon to all in this forum, BTW.  The above is a long way from a class D disaster, but...unlike the fish (we mourn the small entities that lived with us for awhile, all of them...) here's a chance to 'save a life' in a meaningful way.  I can't resist trying to help, even if only with MHO in a hopeful comment.

Back to saving an amp...;)
asvjerry's avatar
asvjerry
609 posts
 
"I'm not black, but sometimes I wish I wasn't white."
-Frank Zappa's observation on the Watts Riot.

I could see the smoke from my home.

*Looking at my hands, my arms....*
We call This 'white'. No.  Albinos are white.  What we have here is a rather miserable mottled beige, streaked with blue-green veins and reddish-pink blotches nearly everywhere....
Maybe a better description would be 'very bad camo'.  Way too light to be successful at 'blending into' anything but ourselves. *G*
toddverrone's avatar
toddverrone OP
838 posts
 
That was great, Jerry. I actually chuckled out loud!
toddverrone's avatar
toddverrone OP
838 posts
 
Also profound, on second reading..

A miraculous thing has happened. After unplugging and reseating all the connectors to the board then taking out the fuse, checking it for continuity and reinstalling it, I hooked up the amp to double check I didn’t have a brain fart when I was trouble shooting the first time. Lo and behold! It works!

Sounds as good as the day I got it. No more sound cutting out, no more distortion. What the dickens?

@atmasphere thanks for questioning my trouble shooting! I went back and re-read what I wrote. I did swap RCAs, it stayed with the amp, not the signal. But, just to be sure after reading your post, I thought I’d double check. Vielen dank!

Final result is a resurrection! Hallelujah!
The new, repaired and double tested ICs sound great as well. A pretty solid Wednesday night!

Thank you for all the input and stories of fellow stupidity. Shared suffering...
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