DB25 Pinouts

Don't want to spend the big bucks on a DB25 to RCA cable just to hook up your DVD player to a 5.1-capable receiver or preamp? You can make one on your own if you're not afraid to use a soldering iron and buy a few parts from Radio Shack.

Here are the pin assignments for THX DB25 audio connectors as found on several home theater components like ADCOM's GSA-700 series processor/amplifier.

Diagram of the GSA-700's DB25 port

Pin 1 : Left Channel
Pin 14: Left Channel Ground
Pin 2 : Center Channel
Pin 15: Center Channel Ground
Pin 3 : Right Channel
Pin 16: Right Channel Ground
Pin 4 : Subwoofer Channel
Pin 17: Subwoofer Channel Ground
Pin 5 : Left Surround Channel
Pin 18: Left Surround Channel Ground
Pin 6 : Right Surround Channel
Pin 19: Right Surround Channel Ground

To build a cable, you'll need to cannibalize a few RCA cables. I cut a few old audio cables in half and soldered them to a DB25 connector purchased from Radio Shack. The results looked something like this:

It's not a pretty cable, but back when I first got a real job, I couldn't afford a preamp with an AC-3 decoder. I had a Panasonic DVD player with a built-in AC-3 decoder, and an Adcom GSA-700 with a 25-pin input. Monster wanted something like $150 for the cable, and they seemed to be the only one I could find carrying them. My homebrew cable cost less than 20 bucks all total, and I was finally able to actually experience 5.1 channel surround sound at home.

The cable is covered with electrical tape to keep the wires from getting tangled. If you squint hard, you might mistake this cable for an "audiophile" cable. :)

Disclaimer: This information is provided without any warranty whatsoever. If you blow up your preamp, it's on your head! Soldering the audio cables onto the DB25 connector can be tricky if you're as much of a novice with a soldering iron as I am.