CD Player Destruction!
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Joined: May 2004
Posts: 121
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From: Charleston, SC
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CD Player Destruction!
In order to have to bomb turbo kit, i need the aem ems (it'll come out soon!), to tune it i need a computer, right, so why not just add one to the car. Great idea, i can watch dvd's and have 40gb of mp3s! sweet,now i just gotta get the audio to the head unit, luckly my sony xplod has a bus input, easy enough... well not true...
The sony head units use a system called unibus, which is now my worst enemy ever, its a data/clock/remote control stream to interface with cd changers and all other sony products so the display can show track names form the cd changer, cool, well not for me, because the bus inputs dont become active unless told by the unilink processor to be enabled. hmm enter the soldering iron...
I got the schematics for a similiar sony cd player and used them a base for my electronics adventure, being an nuclear trained tech in the navy im not scared of big schematics. ill say it did take some time to track down what i was looking for in the circuit, i found the audio out from the cd player module and de-soldered the pins and attached the pins from the audio bus in connectors on the back. for some reason my digital camera took a dump and lost the pictures of that step, poo. anyways the result of that modification. I put the computer in the car, powered everything up and... no sound. then i started playing with the volume controls. with the computer master volume, wave volume ,winamp volume and cd player volume at 100% it sounded like 1/4 the volume of the radio and the signal was horrible, crappy, **** poor audio quality. So gave up for the night. So today at work im talking to my staff advisor (im a student learning about nuclear submarines) and he suggested a audio transformer, ok so imagine like 2000+ super geeks all running around trying to learn about neutron decay constants and that equals my work. anyways, he told me the cd player probably had a higher voltage requirement than the computer sound could sould supply. then i remembered back to basic electricity... impedance matching. the headunit was loading the sound card too much causing audio distortion and attentuated signal. to radio shack...
Well the final product. i booted the computer, connected the audio cable, and adjusted the volumes, computer master, wave, and winamp at 100%, head unit at like 20% = radio volume with mp3 quality! i couldn't believe it. two $3 transformers were my solution! I was kinda worried about the transformers b/c they had a frequency response of 300-10000hz +- 3db and everyone knows good base <250hz but they work perfect. Ill post more final pics when my screen and video card gets in so i can get rid of the monitor in my passenger floor board
-- Jeremy
The sony head units use a system called unibus, which is now my worst enemy ever, its a data/clock/remote control stream to interface with cd changers and all other sony products so the display can show track names form the cd changer, cool, well not for me, because the bus inputs dont become active unless told by the unilink processor to be enabled. hmm enter the soldering iron...
I got the schematics for a similiar sony cd player and used them a base for my electronics adventure, being an nuclear trained tech in the navy im not scared of big schematics. ill say it did take some time to track down what i was looking for in the circuit, i found the audio out from the cd player module and de-soldered the pins and attached the pins from the audio bus in connectors on the back. for some reason my digital camera took a dump and lost the pictures of that step, poo. anyways the result of that modification. I put the computer in the car, powered everything up and... no sound. then i started playing with the volume controls. with the computer master volume, wave volume ,winamp volume and cd player volume at 100% it sounded like 1/4 the volume of the radio and the signal was horrible, crappy, **** poor audio quality. So gave up for the night. So today at work im talking to my staff advisor (im a student learning about nuclear submarines) and he suggested a audio transformer, ok so imagine like 2000+ super geeks all running around trying to learn about neutron decay constants and that equals my work. anyways, he told me the cd player probably had a higher voltage requirement than the computer sound could sould supply. then i remembered back to basic electricity... impedance matching. the headunit was loading the sound card too much causing audio distortion and attentuated signal. to radio shack...
Well the final product. i booted the computer, connected the audio cable, and adjusted the volumes, computer master, wave, and winamp at 100%, head unit at like 20% = radio volume with mp3 quality! i couldn't believe it. two $3 transformers were my solution! I was kinda worried about the transformers b/c they had a frequency response of 300-10000hz +- 3db and everyone knows good base <250hz but they work perfect. Ill post more final pics when my screen and video card gets in so i can get rid of the monitor in my passenger floor board
-- Jeremy 
