Friday, March 16, 2012

I ain't got a gat, but I got a soldering gun...

If you're reading this, it's because you have an NZXT Vulcan case that is giving you horrid audio artifacts through the front audio port because of the ground loop they designed into their printed circuit board.  Here's what you need to do to fix it.
Here you can see that the path from audio jacks to the audio ground wire is shared with the same path that's used for the USB.  In order to eliminate the ground loop (and the annoying sounds that come with it) you have to separate the grounds. 

Using a dremel with an engraving tool, I separated the front audio cable header ground wire from the rest of the circuits. 

Then I separated the audio grounds near the jacks from the everything as well.  
Then I soldered a wire connecting the grounds of the jacks (you only need to do one since they're both connected) and then solder it to the ground wire on the header.
That's all you have to do. I had originally just jumped a wire from the headphone over the header ground, but it stuck up too high and broke off when I installed it in the case. So I ended up laying a wire flat and running it like a trace on the pcb.

This eliminated all the noise I was picking up through my front audio headphone jack, and the speakers too.

NZXT - if you read this, you owe me money for the engineering re-work on your case design. Thank you.

I do have to hand it to NZXT though. I sent them an email describing my problem with my case, and they responded by sending me a new front audio/USB cabling and hardware. Which, kudos to them for sending me something, rather than just blowing me off. Yet they sent me the exact same pcb and it didn't fix the problem. It did give me enough confidence though to modify one of them to see if I could do it, with a backup in case things went wrong.

Fortunately, this worked out great, and now I've got a replacement part if I ever need it.

I also have to hand it to Creative, as after this, the X-Fi Titanium really shined. The audio quality is fantastic. I also like how the 'modes' keep track of settings for headphones and speakers separately, and automatically switches when I plug my headphones, or unplug them. That way the CMS3D is on when the headphones are in and on game mode, but off when using my 5.1 speakers or listening to music with headphones. Nice. I had to do it manually with my old card. It's really a nice piece of hardware and sounds great. And for 36 bucks, it was a steal! In a way I almost felt sorry for Creative: I wondered how many people returned these cards under the presumption they were defective, when all along they were really fine and their case was a bad design like mine. At any rate, it ended up benefiting me because I got one on the cheap because of it.

But then I'm reminded of the headache of their software and the planned obsolescence Creative has embraced to maintain their cash flow, and think: I'm glad I didn't have to give them more money than I had to because I know my card will be obsolete before it really should be.

7 comments:

  1. Thanks so much for posting this! I have the phantom case and I've been trying to work out what those noises were since I got the thing last year. Googling got me as far as realising I had a ground loop but finding out where had me completely stumped! I can build a PC but I'm clueless with electronics so this was very handy. Quick question, if you don't mind :P The wire you soldered in, will any old wire do or is there some specific type I should get?

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  2. It shouldn't make much difference in the wire. I had some small gauge solid wire laying around from an electronics class from college. It worked well as it was pretty stiff and would hold its shape. It made it easier to work with. But any wire should do as long as it's connected. But you don't need 12 gauge wire either.

    I don't know if your printed circuit board is different than mine, but be sure to check where your grounds are and to separate and solder appropriately. I say that because the header pinout at the board on the NZXT side didn't match the standard motherboard audio pinout on the other end for my case. So yours could be different as well. Use the motherboard/soundcard end, find the ground there, and follow it up to the pcb end and you should be able find the right gound pin.

    Here's a standard audio header pinout.

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  3. Although looking at your case on Newegg, it very well may be the same as mine. Good luck!

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  4. Thanks for the help, you are a star :)

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  5. You are more than a star, you're a rainbow shooting unicorn! Thanks to your very clear and handy guide I had my headphones sounding noiseless and crystal clear in less than 20 minutes. Big ups to posting this and helping people out, you are appreciated.

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  6. Just built a new system using an NZXT Gamma case and it has the same problem. Thankfully it mostly only acts up with one of my mini thumbdrives and even then a little wiggling sometimes fixes it. Don't know if I feel like tearing it back apart and trying my awful soldering hand out just yet but at least I'll have an idea of what to do. I'll leave this bookmarked for a rainy day. Thanks.

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  7. Hello! Thanks for sharing - I have NZXT Vulcan case too and that issue is driving me nuts! I wouldn't ever suspect it is case of badly designed pcb - I thought power supply interfered with the USB cable, LOL
    once again - superb find, thank you!

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