System issue, looking at new power supply

[Docjon]

I upgraded my computer last month in preparation for Battlefield 3. My system is listed below, with the smaller/darker text describing old/removed components.

Windows 7 Pro - 64-bit

four sticks of RAM of currently unknown name/spec, for a total of six GB
Two sticks of Corsair Vengeance 2 GB PC3-12800 1600mHz (PC3 12800) 240-Pin DDR3 SDRAM 1.5v Dual Channel (four GB total)

Intel Core 2 DUO E4500 Allendale, 2.2 Ghz
Intel i5-2500K 3.3 Ghz

Gigabyte GA-P35-S3G motherboard
GIGABYTE GA-Z68P-DS3 LGA 1155 Intel Z68 HDMI SATA 6Gb/s ATX Motherboard
Realtek ALC889 on-board sound

Nvidia GTS 250

250 Gig IDE HD (retired due to age/incompatibility)
500 Gig WD Black HD
Pioneer DRV-215D DVD drive

ASUS VH236H Black 23" 2ms LCD Monitor (1920 x 1080)
19" Dell CRT

KINGWIN ABT-450MM 450W - 3.5 years old

The Problem
Recently I've had some sound issues in Teamspeak. When not in-game, I sound fine to everyone, with some very faint buzzing/humming in the background. However, when I go into a game (single player or multiplayer, and which game doesn't matter), the buzzing/humming becomes quite loud. Everyone sounds fine to me regardless of what I'm doing. Bear in mind that everything had sounded fine for weeks, then one day, buzzing sounds. I had installed no new software, nor changed the hardware or drivers between the day when I sounded fine and when I didn't. Nothing new had been plugged into that electrical circuit, anywhere in the computer room, or even in the entire house. Nothing had been unplugged, and no cables had been moved. Since the problem developed, I've checked all cable connections.

After uninstalling/reinstalling sound drivers (the latest from Gigabyte's website), trying different headsets, and rolling back my system to an earlier restore point, I'm at a loss as to what could be causing it. I can only assume some piece of hardware is being stressed while in-game. Perhaps it's the on-board sound going bad after working fine for a few weeks. Perhaps my video card is giving off EMI when stressed, and is getting ready to go. However, this has been a real puzzler to me, and when weird issues pop up that are difficult to pin down, I start to suspect the power supply. Having one guy in my clan eventually say the noise, "sounds like my power supply did when it was starting to go." just pushed me further in that direction.

So, if someone disagrees with the theory that it's my power supply, I'm ready to listen to alternatives. Short of that, I'm thinking of picking up this replacement:

Antec EA-650 Green
http://www.amazon.com/Antec-EA-650-Green-Energy-Certified/dp/B004NBZAES/ref=pd_sxp_f_pt

Opinions? I know there are some that would rather I pick up something closer to the $150 range, but after my other upgrades, money is short. Not as in, "I won't be able to buy 2 Starbucks every day.", I mean really short.

Future Upgrades
In the near future, I will be picking up a new hard drive - probably another Western Digital Black in the 500-750 GB range. Also, I hope to be replacing my GTS 250 with a new sound card. Eventually, i will likely add another 2 sticks of the same RAM I listed above, for a total of four sticks and 8 GB. That's it.

 

[Zero82z]

It may not necessarily be the PSU, but it would certainly be a good idea to upgrade from that unit. It's a Kingwin so it's probably half-decent, but it's still just a 450W PSU with an old design and has no PFC. The 650W Earthwatts is a good unit, although if money is really that tight, you could certainly make do with a PSU in the 500W range, like an Antec NEO ECO 520W or a Corsair CX500/CX600.

If the PSU replacement doesn't solve the issue, consider buying an inexpensive dedicated sound card, such as an ASUS Xonar DG.

 

[Docjon]

It may not necessarily be the PSU, but it would certainly be a good idea to upgrade from that unit. It's a Kingwin so it's probably half-decent, but it's still just a 450W PSU with an old design and has no PFC. The 650W Earthwatts is a good unit, although if money is really that tight, you could certainly make do with a PSU in the 500W range, like an Antec NEO ECO 520W or a Corsair CX500/CX600.

If the PSU replacement doesn't solve the issue, consider buying an inexpensive dedicated sound card, such as an ASUS Xonar DG.

I can't currently find the Neo Eco 520w for the $55 I can get the 650w Earthwatts for. NewEgg had a sale, but that seems to have ended a few days ago.

Yeah, I figured upgrading the PS at this point wasn't a bad idea, even if it didn't fix the problem. I'll keep your sound card suggestion in mind, but I hope I won't need it.

 

[Tsumi]

Where is your sound plugged into?

 

[Docjon]

Where is your sound plugged into?

I'm using on-board sound, and the only 3.5 mm mic/headphone jacks are in the back. More info on the on-board sound is linked in the OP. Click on the Gigabyte motherboard link.

Thanks for replying.

 

[Tsumi]

Oh, so using the motherboard connectors on the back I/O plate?

I ask because I don't have any electromagnetic sound issues from the back sound, but my front panel sound has those issues. Apparently it doesn't have the proper filtering system or something or other.

The MSI Big Bang XPower has a dedicated sound card that sits right on top of my graphics cards. I hear no hissing noise whatsoever from the rear ports, but I do get them from the front. If you're getting them from the rear ports, I think there may be something wrong with your motherboard.

 

[Docjon]

Oh, so using the motherboard connectors on the back I/O plate?

I ask because I don't have any electromagnetic sound issues from the back sound, but my front panel sound has those issues. Apparently it doesn't have the proper filtering system or something or other.

The MSI Big Bang XPower has a dedicated sound card that sits right on top of my graphics cards. I hear no hissing noise whatsoever from the rear ports, but I do get them from the front. If you're getting them from the rear ports, I think there may be something wrong with your motherboard.

Something to keep in mind. It's been a worry of mine that the on-board sound is bad ever since this started. Thanks.