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Auxiliary Input
Reason - The ability to have a "clean" line input to the factory headunit is something many Saab owners have wanted for a long time. Several have hinted at doing this, but no one has come up with any specific details. The choices are: FM Modulator, which gives static feedback at times and can also be more difficult in dense (radio stations) areas; cassette adapter that gives considerable amounts of feedback or more difficult tap its inputs; hack the CD changer cable. The best route seems to be the latter - hack the CD Changer cable. Also, because the Clarion C-bus communication protocol has been replaced with newer technology, there isn't anything worthwhile to make an Aux-in easy, such as a purchasable adapter.
Research - Searching the topic brought me to several locations. The most notable was among the many Volkswagen owners looking for the same thing - VW Switchable Aux input - http://cloud13.com/vwaux/instructions.html - The idea is to install in-line with the L/R channel inputs a switch that allows one to choose either CD input or Auxiliary. By doing it this way, there is no need to "hack" the C-Bus "handshake;" a CD is attached and spinning, so the headunit recognizes the connection. It was a result of this link that I was able to confirm my suspicions, and muster up the courage to attempt this.
Personal - My CD Changer was the first purchase for my Saab since it did not have one at the time of sale: model - Clarion ProAudio DC625. The changer came with a cable, but as most Saab owners know, most (almost all) NG900s had the cable run from the headunit to the boot (as was my case) regardless of whether there was a changer attached at the other end. This spare cable seemed to be the perfect donor to the project, so I decided to test out this idea with the spare before I went hacking the "good" cable. When you're ready, the CD cable runs down the driver's side kick panel.
I am coding a website for myself, so this is actually written for that (and includes pictures), and should be available in due time. Tomorrow's the six-year anniversary, and among other things, I have been quite distracted, so thanks for your patience.
So enough with the babble... onto the details...
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Insert normal disclaimer that this may ruin your wire and thus the connection to your CD Changer, no liability, etc. etc.
Do at your own risk!
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First, I needed to "decode" the wires within the cable. Using Richard Bevan's excellent Saab Audio Guide for the NG900/93 I was able to do just that.
http://audioguide.saabnet.com/
1 - C-Bus Data - Pink (thin)
2 - C-Bus Clock - Light Purple (thin)
3 - Blank - Brown (thick)
4 - C-Bus Service Request - Light Blue (thin)
5 - Blank - Orange (thick)
6 - Signal Ground - Black (thick)
7 - CD L-ch input - Green (thin)
8 - CD R-ch input - Gray (thin)
9 - Blank - Black (thick & glossy)
10 - Back Up - Red (thick)
11 - Remote Control - Light Green (thin)
12 - Ground - Black (thick)
13 - Blank - Purple (thin and "snipped")
With this "key" one can see that it is the wires for L/R ch inputs that need to be tapped for the Aux-in. However, they are a bit "hidden." They can be found wrapped up in "foil" and then by a gray insulation. When you split open (carefully) the CD Changer cable you will see (10) red, (5) orange, (1-4) gray (very thick), (9) black/glossy, (3) brown, and the desired foiled-covered L/R ch input wires. I removed probably 2-3 inches of the covering to give me ample space to work with.
When you isolate the covered L/R ch inputs, you can simply snip the wires because they will be re-connected in order to get the desired switching-effect. I actually stripped the cover off, which allowed me to see the two wires including the insulation. That way I could snip just the thin Green and Grey wires without cutting the insulation. It will be apparent when you do it.
The basic overview is attaching the snipped end that goes to the CD changer to one side of the double-pole, double-throw (DPDT) switch and the end that goes to the headunit should be attached to the middle (constant output) of the DPDT switch. For the other side of the switch, two wires should be connected. These will go to your RCAs and ultimately be your auxiliary input. The "hard/tricky" part is knowing that you need to maintain a ground to have a clean connection. "The better the ground, the better the sound."
I accomplished the above by soldering in wire to extend the L/R ch inputs on both "ends." I ran wires about two arm lengths, so perhaps several feet; it has to be enough to get from the cable, to your switch, wherever you decide to place the switch, and as always, I felt it was better to have too much than not enough. I had high-end speaker wire lying around, so that is what I used. Additional short pieces of wire was used to connect the "ground" wire between the two maintaining the connection that was previously there. [SEE ABOVE PIC and BELOW PIC] An additional ground that should be the same length as the other L/R wires needs to be connected, as this will be used for the ground on the RCAs.
With all of these connections made, and your wires clearly marked (TO HU and TO CD), this "joint" can be taped up and considered completed. The hard part is done and the only connections left are the RCAs and to the switch.
Separately, two wires need to be connected to RCA inputs that I picked up from the Shack. The "line" wire is connected to the end of the RCA plug and soldered on to maintain the connection. In addition, a ground needs to be connected. I chose to share the ground between the L and R RCAs, so a short wire was connected between the two and then the ground wire from the CD Changer cable gets soldered here.
Now it's a matter of connecting the six wires properly to the DPDT switch (you do have 6 wires correct?! 8oD ) The "TO HU" should be connected to the center of the DPDT switch; this means the connection is constant to the headunit. Then, the other two pairs of wires (TO CD and the newly created RCAs) are connected to the outer ends of the switch.
What happens is that the CD Changer is still connected and running. Therefore, the "handshake" that occurs when one pushes the CD button of the headunit is not disrupted. Now, when you want to listen to the CD Changer, the switch is positioned that way; want AUX, "flip/push" the switch and play the MP3/DVD/etc. Easy as that. The CD will continue to spin, so you will loose your "place," but that's what the seek button is for, and how you get around Clarion's (Saab's) proprietary connection; it's a trade-off. The only downside is when the CD changes, as there will be an interrupt in the AUX signal (quick mute). I plan to use a "blank" 80-minute disc of nothing. This will avoid any seek issues.
Please be sure to fully test this prior to "Closing" everything up. Because of the location of my switch and soldering the connections to the back of the switch, I had to cut the six wires and reconnect with plugs in order to feed them through the hole I drilled for the switch. Unfortunately I did not label correctly, and put together, pulled apart, put together, trying to get things "working" when I know they did work! This caused me the usual "Why doesn't it work!!!" stress.
The last piece is the "finishing" touches. Where should you put your switch? Where do you want the Aux wire coming from? I chose to use my cell phone mount, as it is both out of the way and "stealth." For the cable, I decided on the driver's side kick panel because I would most likely mount my MP3 player where my old cell phone was held, which is just off to the right of the steering wheel/top-left of the SID/stereo.
And there you have it. I do have a spare cable I may be willing to part with. I'm not sure what it's worth to people, but I may also be willing to make these up for a nominal fee (no Scott, this is not intended as selling these and if enough interest, I will take out a classified).
Questions, Comments, Observations are of course welcomed. Thank you to the VW sites for laying this information out there. And of course thank you to SaabNet for all of the additional help (outside of this)! I am happy that I can finally contribute something original and hopefully of value to all of the valuable members here!!!
Cheers... Sean
posted by 69.160.15...
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