Is there a soundcard for the t3604 with a output mixer on it

The eMachines T3604 desktop computer uses an Intel 945GCL motherboard,

http://www.ascendtech.us/intel-d945gcl-1066fsb-ddr2-pcie-x16-sata_i_mb4intd945gcl.aspx

(No, not advertising. Just a good photo of the motherboard, if you slightly scroll down)

Look at the chart below the photo of the mobo. (MOtherBOard)
Expansion Capabilities:

A) Two PCI slots (Two PCI Conventional bus connectors. Long white slots)

B) One PCI Express x1 bus add-in card connector.

(PCI Express x1 slot. The longer PCI-Express x16 slot is on top.
Then the two long white PCI slots. Then the shorter black PCI-Express x1 slot)

You can use a Sound Card in an available white PCI slot, or if the black PCI-Express x1 slot is open.

Yes, I know, I'm getting to it, lol!

The Onboard Audio -> Intel High Definition Audio, doesn't have an output mixer feature.

My onboard audio - Realtek, (And on an Intel mobo), does.

[ Intel 915G (Southlake) motherboard.
Has a Realtek audio chip, ALC860. I use the Realtek Audio Manager. Has Sound Effects, and an equalizer.
What happened from the Intel 915G to the Intel 945GCL INTEL?
Sheesh! ]

Suggest this if you have an open, available PCI slot,

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=4459743&CatId=2771

This, if you only have the PCI Express x1 slot open,

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=420799&CatId=2771

I don't recommend a USB sound card, but you may,

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=5344879&CatId=2771

(Usually only 16-bit.
Plugs into a USB port where the contacts are not gold plated, as on a PCI sound card, or PCI-Express x1 sound card.
I'm old school, and probably need to evolve ; )

Plus use Virtual DJ,

http://www.virtualdj.com/download/free.html

Mixing Tips;

1) http://www.youtube.com/watch?v=dkGAFTXidKs&feature=related

2) http://www.youtube.com/watch?v=FQ62zoVIKB4&feature=related

3) http://www.youtube.com/watch?v=nn6nsXpX7bU&feature=related

Regards,
joecoolvette