Parallel 2 music jacks to single music input?

[Bushcaddy]

I have a PMA 4000 audio panel. I also have a Garmin 496. I know from research here on VAF that the audio from the Garmin needs to come out of the 1/8 jack on the back of the 496 and go to annother 1/8 accessory jack that is hooked to the music input of the PMA 4000. I would also like to be able to use an Ipod and don't want to have to unplug the 496 and lose any warnings while the music is playing. I'm wondering if I can parallel two music jacks and plug in both devices to the single music input on the audio panel???
I sent an email to PS Engineering as well but thought I'd throw the question out here to see if the brain trust has an answer. thanks....

UPDATE: Spoke to Mark at PS Engineering...can't parallel the jacks, he did think there had to be a way to do this though

[lostpilot28]

Hi Don,
One thing I would consider is that if your audio panel doesn't have enough aux inputs, that you use one on the radio, if it has them. My EFIS has "Betty" and I originally had it piped into my only aux input on my intercom. It was causing a significant audio problem, so I called the people at Flightcom and they recommended having Betty go into the iCom A200 radio aux input. That worked out perfectly.

You'll probably have to strip one end of the 1/8" jack and have the signal wire crimped onto a pin for your radio. That's how I had to do it.

[AZtailwind]

Originally Posted by Bushcaddy

I would also like to be able to use an Ipod and don't want to have to unplug the 496 and lose any warnings while the music is playing. I'm wondering if I can parallel two music jacks and plug in both devices to the single music input on the audio panel???

I would install the audio in one of the unswitched audio inputs and leave the music input.....for music. Problems with impeadance matching can drag down the audio in with intercom/panels. That 4000 is a good unit with many other audio ins; just for what you are trying to do...my 2 cents

[dhall_polo]

I've spliced to audio jacks to one input. works on my machine.

[Brantel]

You could use one of these:

http://www.vx-aviation.com/page_2.html#AMX-2A_more

or....

Some people just parallel the inputs but use a resistor on each source before the summing junction which connects to the input like this:

source#1-------/\/\/\/\/--------input to intercom----------/\/\/\/\/\---------source#2

This is a simple passive mixer. This keeps the sources from fighting each other.

[uk_figs]

I wired my 496 through a switch to the PS3000 so you can switch between the 496/XM or external music input. I also found a circuit on the web that would allow you to feed the 496 external speaker output (brown wire) into one of the other inputs for the voice alerts but decided I did not want to risk frying the intercom
If you are interested in the schematics (.sch format) let me know and I will email them to you

[SteinAir]

Others have given some good hints. One thing we usually do in this situation (and even with full blown audio panels) is to use a switching aux jack which normally will leave the music source wired direct (through the jack) and then when you plug in the Ipod/CD Player or whatever, it shuts off the feed from the 496 and switches to the feed of the plugged in unit. No relays needed, no balancing, drain, or backfeed to worry about.

My 2 cents as usual!

Cheers,
Stein

[xavierm]

A dual headphone Y connector may work. They have them at Radio Shack. "The Shack" as they want to be called now.

[longranger]

It's not good practice to parallel audio outputs directly, ie. don't connect two outputs to one input. For your music input, find another existing input, or go with the mixer Brantel suggested.

[rich]

Here is another source for mixing inputs.

http://www.fdatasystems.com/AP_60.htm