Problem Connecting both CarPC & H/U Audio in Amp!!!

**togaf** · 05-16-2005, 06:02 AM

I don't have an aux in option on my H/U.

Using 2 into 1 RCA "y adaptors" to connect both carpc (MII12000) & Alpine H/U (line level output) into my amp (4 channel) is causing problems. With just the carPC connected to the amp audio is great, until you connect H/U input (also line level) into y adaptor simultaneously, in which case volume drops dramatically and interference is audible (even where the h/u is switched off). Vice versa is also true.

I've searched the forum and have found this should not be a problem (eg. Looking for a 2-way audio switch.

Only option I can think of is to connect the H/U into the CarPC line input and only run one source into the amp however this may have its own issues???

**ABSolute** · 05-16-2005, 06:24 AM

Depends on the type of radio you have, if you have the possibility of an
AI-net cd changer you have an audio in on your radio.
There is a converter cable from RCA to AI-net.

**ALonDonThinG** · 05-16-2005, 08:00 AM

I have the same problem. ive found this info http://www.tkk.fi/Misc/Electronics/c...s/linesum.html i have ordered the bits to make the circut, i let you know if it works.
The other way is to use an audio control unit with aux in, @£300

, or an rca switch box, but if like me , you will want them on at the same times so you can hear your gps talking.

**togaf** · 05-16-2005, 06:51 PM

Originally Posted by ALonDonThinG

but if like me , you will want them on at the same times so you can hear your gps talking.

Yeah, that's exactly what I'm wanting to do! Interested to see how you go.

How exactly does one go about applying the resistor to the cabling? Does it go on the centre conductor (audio line) or shielding?

Also, I take it where I split 2 RCA outputs from carPC into 4 (for conecting into 4 channel amp), I only need to apply two resistors before splitting?

**ALonDonThinG** · 05-17-2005, 04:17 AM

Hi togaf
Ive solved my problem, but in a different way, when i ordered the resistors i also got a ground loop isolator, ive installed this between the radio and my line in on carpc and
BINGO! all clear now. This is the best solution for me, i also used an rca switch box
so it is possible to use the radio with carpc shutdown. If you try to make the mixer, apply the resistors to the center signal wire.
Good luck , pm me if you get stuck.