New CarPC - this one for tuning - Page 3

RoyH · 01-08-2007, 04:21 PM

Hi there,

Was surfing the net, cause I just bought an X-Meridian and was looking to change the 1/8 minijack connectors for RCA when i came across this forum and this thread in particular. Great forum by the way.
Is the picture i attached a correct interpretation of the layout of the minijack pins? Especially the + an - poles interest me.
I assume one can solder cables to the rca connectors and to the pins on the board, but what sort of cable is best used for this?

Thanks in advance guys

RedGTiVR6 · 01-08-2007, 11:56 PM

I'm currently at CES.

I have a sketch describing what the industry standard is for these jacks. I spent a good deal of time talking with an engineer today about that very question.

I had metered out the jacks while they were on the board by plugging in an 1/8" to RCA splitter, then again when the jacks were desoldered.

I did find out that it's standard to do an auto muting on these jacks because if it's left open and there's nothing plugged into the port, there will be a good deal of noise.

As for what cable to use...we will be getting an extra cable that's the same as the RCA cables we will be using. With this cable, we'll cut it up and make the 'jumpers' to go from the board to the RCA sockets. Hope that helps!

RoyH · 01-09-2007, 02:47 AM

Red, thanks for your reply,

Maybe you can post pics en parts to use to do this mod (when you're finished with it) so i can copy the whole process

Lots of fun at CES.

RedGTiVR6 · 01-09-2007, 10:02 AM

Parts to do the mod will completely depend on how nuts you want to go with it.

All that's really needed is a desoldering gun (I paid $13 or so for mine, it's really a cheap gun, but for this it works). A few RCA sockets...as far as which ones...that's completely up to you. Those RCA sockets would probably cause a lot of people on this board to have a heart attack after seeing the price for such a piece.

I'm tossing around the idea of replacing the electrolytic caps that are on the board with polypropolene caps for an even better sound. I need to get back home and see the card up close and look at what it's going to take to do so.

The OpAmps literally just pop out of the board and you replace them with the ones you think sound best. Just need a small, flat blade screw driver. Like what would come in a computer maintenance kit.

XC-C30 · 01-09-2007, 10:44 AM

Red...... you are NUTS

In a good way ofcourse

Have fun and yeah mounting it all in a case inbetween your backseat isn't such a bad idea, since there's more space inside the case to wire up everything so you don't get noise from cables crossing your HDD and such.....

RoyH · 01-09-2007, 11:14 AM

Red,

I'm not that nuts as you seem to be, in a good way ofcourse.
I already ordered new opamps, dont foresee any problems with mounting them.
What I still havent figured out is this:
The RCA needs two cables soldered to it: ground and signal. Where one the soundboard do these signals come from.
For example: front left and front right are combined in the stereo jack connector (you desoldered). Desoldering this connector leaves 5 sockets. The RCA only needs 4 maximum for two channels (ground not combined: signal left (1) + ground (2), signal right (3) and another ground(4))
If i understand correctly one of the two sockets i marked + and - (same colour) provide the signal and the socket i marked ground provide ground. Is this correct and which one, + or -, give the signal? What does the leftover socket do?

I'm not sure if im clear enough, but please give it a try.

Kind Regards, Roy

RedGTiVR6 · 01-10-2007, 09:43 AM

I've attached a diagram that describes how these 1/8" plugs work according to the lead engineer and designer for Orca Design.

One of the pins on the board will be ignored. Because of the design to prevent noise, any sockets that will not be used will need to be shorted perminately while they are not in use.

As for exactly what pins do what...in order for me to get that I'll have to be at home and use a meeter on the board again.

Caelric · 01-16-2007, 08:56 PM

Hey red, here's a question for you:

I just built a new CarPC (upgrade from my old one, that has a PCI slot and a PCI-Express slot. The PCI-E holds a graphics card, and I was going to put a Creative X-Fi in the PCI slot. I bought this motherboard (Kontron 986) for the express purpose of being able to hold a graphics card and a sound card at the same time, but it seems as if the graphics card is causing some noise in the sound card. Any idea how to fix this? (The noise is not from any other source in my car, as the previous CarPC worked just fine with a SB Audigy USB sound card and no noise whatsoever)

Dave

RedGTiVR6 · 01-17-2007, 11:31 AM

Have you removed the sound card and tried using onboard sound to test this theory?

Caelric · 01-17-2007, 06:23 PM

No, I'll go ahead and try that.

RedGTiVR6 · 01-17-2007, 07:16 PM

bah!

I can't believe I wrote sound...I ment video....I really really don't know what I was thinking....

I must have been on the phone while I was typing....

wow - I can't believe that...lol

scott_fx · 01-17-2007, 07:19 PM

red please stop supporting thread jacking...

Caelric · 01-17-2007, 07:36 PM

Sorry 'bout that.

RedGTiVR6 · 01-17-2007, 07:52 PM

hehehe

sorry!

Caelric · 01-18-2007, 08:49 PM

And one more, to finish the 'jack.

It turned out to be a bad video card. With another card, or onboard video, the sound is fine.

So, now I have my ultimate: a PCI sound card and a PCI-Ex video card, on the same mini-ITX board.

The sound card is currently a SB X-Fi; in order to bring this back on topic, how is your project with the Auzentech coming? I might get one to experiment with as well.

Dave