From mp3 to Sound System

[pologenius21]

I want to create a portable amplifier that I can plug into the headphone jack on one end and into any sound system like a projector, or home stereo, or even a cd player. One question is how do i hardwire R and L audio jacks to my cd player in my car. lets talk about this and come up with something cool

 

[davelectronic]

Amp

How about to the left and right channels, what else is there to it. ?
Dave.

 

[pologenius21]

yea sounds simple but I have no clue how to identify R and L channels on the motherboard.....there's lots of Rs there. I'm pretty sure I'm looking for R out and L out right

 

[electronboy]

yupp im purdy sure thats right but i could be wrong

 

[davelectronic]

Amps audio

Yupp thats probably it, like the avatar electronboy, cool.
Dave.

 

[MattyMatt]

well I can tell you this, standard wiring of a headphone connector (stereo) or TRS connector:

Tip - The very end of the connector - Usually Left channel (positive L - #3 in pic)
Ring - The part between the 2 insulating rings (#4)Usually Right channel (positive R - #2 in pic)
Sleeve - The part furthest from the tip - Usually ground (#1 in pic)

I say usually because sometimes they are reversed or setup a little differently depending on the manufacturer.

Once you know that, you can look at the connector on the board, and you may be able to see where some of the connections go.

Good luck and have fun!
Matty-

 

[pologenius21]

thanks matt. i think i've got them all together now. tomorrow is test day. let me ask you this. what do you think about wiring a digital watch display into my safety glasses at work? possible? probable? complex?

 

[MattyMatt]

It depends on what you'd be going for... if its just the time, then it wouldn't be impossible... the display itself may be a little big, what I would suggest, and maybe this is my geekynees coming out, is that you see if you can get a small display (the simpler the better, I like binary for example: http://www.thinkgeek.com/gadgets/watches/6a17 ), and possibly use some sort of reflection to put it onto the front area of your glasses, kinda like a heads up display.... BUT I think size is going to be the issue you run into.

I like the simple LED based things because they can be reflected in any orientation and you can train yourself to read it that way... but I'm a geek

Matty-

 

[pologenius21]

did you see the 8gb video display watch? now that's futuristic. i'd hate to tear it up just in attempt to perfect a prototype.

 

[MattyMatt]

oh yeah, I am a huge fan of the majority of the gadgets on that site... and I would probably never tear something like the watch apart because I could totally see myself using it at work .

 

[pologenius21]

ok so i got everything soldered together. the red wire to ROUT and the green wire to LOUT and the 2 copper wires (one from each headphone) soldered together and to AGND. and now i get nothing on my cd player....that sucks. need help. come together fellow experimentalists!!!

 

[MattyMatt]

Okay, what are the devices on each end? We may have an issue with the level of the signal.

Example:
Mic level output going into a line level input... not so much
Line level output going into a mic level input... turn it down... but okay
Speaker level output going into a line level input... I'm sure you guessed... turn it WAY down... but still okay.

NOTE: headphones are not necessarily "speaker level" its closer to an adjustable gain, slightly amplified line level.

Make sense?

If they are both matched... then there should be no issue.

Let us know what you have there for source and destination and I'm sure we can figure something out

Good luck
Matty-

 

[pologenius21]

Man I really wish I understood what you were talking about. I'm kind of a Noob with lots of potential, so let me try and break this down. I didn't touch any other connections but the ones that specifically said ROUT LOUT and AGND. I soldered the red wire to ROUT then the green wire to LOUT and the two copper wires together and then both to AGND. From what I understand this would be like tricking the CD player into thinking a CD is playing but it's really my mp3 player. tell me what you think

 

[TBennettcc]

What Matt is asking is, Where are the connections for ROUT, LOUT, and AGND? On the physical radio head unit in your car? Where are the red, green, and copper wires coming from?

Some pictures of what you are doing (or trying to do) would be really helpful at this point.

 

[pologenius21]

they're on the head unit. i will get pics today. the head unit is the part that pulls out of the casing right?

 

[TBennettcc]

The head unit is the part of a car stereo that sits in the dashboard and is what you use to control the sound system. Most aftermarket head units are all-in-one single-DIN units, usually with additional outputs to be able to hook it to an amplifier. Factory head units can be any size, and are usually proprietary.

See these pictures:

http://www.google.com/search?tbm=is...=2568l3655l0l3804l9l8l0l0l0l0l148l664l4.3l7l0