Added Line Level Audio Input To Sc430

[guykuo]

I've wanted to add a good line level input to my SC430's Mark Levinson system ever since getting my car, but nobody seemed to have a good solution. I haven't found a single aftermarket adapter for the SC430. Then, I found a little tidbit and contacted Rocky Livingston because he seemed to have been at least partially successful in this endeavor.

Using information and encouragement from Rocky, I opened the SC430 console and gained access to the audio signal harness. I also successfully injected a line level audio signal from my Archos MP3 player. Interestingly I discovered that one doesn't need to pull the head unit to access the audio signal lines. The audio signal and control cables go through a molex connector that is separate from the head unit and lies several inches below the head unit. It is near the right wall of the gear shift console. There are actually two connectors mounted together. The one of interest is the left one with quite a few wires coming out of it. Accessing the signal lines there means I don't need to pull the head unit. Only the wood panel/cup holder assembly need be removed.

Lacking a schematic, I coudn't totally verify my findings but, I believe I have narrowed down the left and right channel signals to the black/white (right) and red/green (left) wire pairs and a gray shield wire on the connector. Indeed, tapping the signal lines and injection of audio lets me pick up or inject audio into the Mark Levinson system. The signals appear to be balanced format with the red and green wires carrying the left channel, while the black and white wires carry the right channel. Direct injection definitely creates clearer audio than my cassette adapter, albeit softer.

As Rocky indicated to me, the volume, fader, and other functions of the ML amplifier are controlled by other control wires in the harness. Substitution of another audio signal by splicing into the audio signal lines leaves the controls active. I can actually adjust balance, volume etc. normally on the head unit while listening to my injected audio signal. Once I build a suitable switching mechanism to transfer the four signal wires between the normal head unit output vs the mp3 player output, I should be able to simply set my switch to select the MP3 player and use the head unit controls as usual. The head unit will simply play its selected source, but the ML processor/amp will instead receive the line level signal of my MP3 player.

My next task was to build a suitable means of selecting a new source input and converting the unbalanced output of my MP3 player to properly feed the balanced input of the ML system. I used a 4 pole double throw switch and a PIE DC blocker to do the trick. It worked! I cut the four audio lines and hooked up a 4 pole double throw switch to let me select between the head unit and signal from a PIE DC blocker. The four lines (Left+, Left-, Right+, Right-) lines to the amp were connected to the switch's center poles. The corresponding lines from the head end connect to their mates with the switch in one position. In the other position the four lines to the amp are connected to the shield and pin lines of the DC blocker.

No more need for a cassette adapter! Frequency response and dynamic range are much improved. No more tape adapter hiss or clackety clack of the adapter spinning either!

Guy Kuo

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Below info about opening the console and the signal lines is from Rocky Livingston.....

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....Correct, the head unit controls are still fully functional. The audio output from the head unit to the Levinson is 2 channel only. The Levinson unit processes and splits the signals for fader/balance etc… It’s a pretty easy process overall. To disassemble the console:

1. Start by lifting the center storage compartment lid and remove the seat heater controls. Press forward on the heater control piece from inside the storage compartment. It easily pops right out.

2. Then set the parking brake and move the gear shifter to neutral.

3. Starting at the seat heater control location, pop out the wood grain assembly on the center console. You will need to disconnect one or two light connectors connected to the assembly to fully remove it.

4. Pop out the wood grain assembly surrounding he head unit. This gets a little tricky because of some of power lid and ash tray wiring, but it’s still pretty easy to remove…

5. Now you should have easy access to the head unit and remove the 4 bolts holding it in place by using a 10mm socket wrench. You may also need to pop out the AC control assembly which is also simple to do. Just grab it with two hands and rock it back and forth until it pops out. It has 4 molex connectors you will need to disconnect.

I don’t remember which 4 head unit leads are audio. I downloaded a schematic off the net to figure out all this stuff… Unfortunately I’m not sure where I filed it.

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........... The below info about the signal lines is also from Rocky. He did his work by pulling the head unit. I'm doing it at the independent molex connector that doesn't require pulling the head unit. My point of attack means less disassembly than if one tries to do the work at the rear of the head unit. Rocky doesn't mention the signals being balanced format, but they certainly appear to be so from my examination..............

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This is a fairly straight forward design. The Pioneer/Toyota head unit, the unit with the with the CD player, has 2 or 3 molex connectors on the rear of the unit. The largest connector, I think it’s the middle one, has a 8 or 10 wires connected to it. 4 of these wires feed audio to the Levinson DSP/Amplifier system, 2 of the wires are a control bus which controls the Levinson sound settings, i.e., Bass, treble, balance, fader, volume…

So, you need to insert an external switch, such as the ones made by P.I.E, between the head unit and the Levinson Unit. I don’t have the cable plug pin-out schematic handy so I can’t tell you which leads to intercept. The external switch needs a ground loop isolator installed on it’s output to prevent hum and engine noise interference.

You will need to install a power switch somewhere to control the P.I.E. interface. When you energize the power input to the P.I.E., the unit will switch from one audio source to the other. I.e., an external XM radio, MP3 player, external aux audio connector etc….Audio controls from the head unit remain unaffected because the control bus from the head unit to the Levinson are unaffected…

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[guykuo]

Audio of head unit can be intercepted at this molex connector. No need to pull the head unit.

The left molex connector is the one of interest. It is the one with cat 5e wire spliced in to carry the audio signals from head unit and audio input lines of ML amp to 4PDT switch. Be sure to resecure and loom the wiring.

The audio signals in the system are normally differential format (balanced) so each channel as a + and - signal carrier. The shield line is the signal ground. This posed problem because my MP3 player as unbalanced (RCA style ) audio output. A DC blocker allowed feeding of the unbalanced signal to the + and - phase signal wires of each channel.

I suspect the video lines of the navigator also pass through this area. Might be possible to intercept and add a video input for the navigator screen here as well. It would certainly be easier than pulling the Nav display out to access its connections.

[guykuo]

4PDT switch for selecting between audio of head unit vs new input. I installed the switch inside the central console's lower compartment. DC blocker was needed to convert unbalanced audio output of MP3 player to feed differential inputs of amp without creating ground loops.

[marsb]

Wow... exactly what I've been looking for.

A few more questions...

1. Where do I get the 4PDT switch (is that a 4 input switch? can I get one that's more than 1 input - maybe for a DVD player/Ipod?) What exactly am I looking for here?

2. I was looking for the DC blocker on PIE's website... once again.. not there... could it go by another name maybe?

Once again, sorry for the stupid questions, but I am really interested in this, and I just can't take the FM modulator anymore.

Please help.

[DAMLEX]

You may very well be my hero. Any video lines in that harness?

[SKperformance]

very nice of you

[marsb]

Ok, I think I found out what you were talking about... it's amazing how easy it is the more you think about it... however, I have one more question... if you're there that is...

The 4pdt switch has 3 rows of 4 poles (Left +/-, Right +/-). You have the 1st row with the stock radio, and the 3rd row with the new input. This leaves the middle (2nd position) open --- which is usually the OFF position. Is that where you connect the output to? Or is your switch somehow an ON/ON/ON switch? I can only manage to find ON/OFF/ON switches... if anyone finds the other type, or if anyone cares to get back to me (and hopefully enlighten my limited knowledge of circuits... PLEASE DO SO.

[DAMLEX]

Memory serving correct the middle would be your output and the two sides would be your switch able inputs. If this is not the case try the other 5 choices. A 9v battery and xmas light usually make good test devices. By any chance did you see any video wires in that bundle? I'm trying to take this a step further and make a switch able line for not only sound, but also video. No room for extra monitors in this thing so I gotta use what's there.

[marsb]

i have one of these... (http://lextasy.com/nav_converter_1160_prd1.htm)... it works for video... sounds like crap though (since I have it FM Modulated now). It's 500 bucks, but if you want video and dont want to ruin your interior with another monitor, you may want to take a look at it.

NOTE: Their website is screwed up... to see the options you're adding, scroll down and you'll have some drop down boxes... with your mouse highlight what "MAY" be there next to those boxes on the left hand side... and voila... text appears (the text colors blend in with the background... ).

Hope this helps.

[DAMLEX]

I saw that on their site before. Was it difficult to install? I was also checking into this other company I found that seems to have a pretty cool solution. http://www.vaistech.com/home.html

[marsb]

I saw that on their site before.  Was it difficult to install?  I was also checking into this other company I found that seems to have a pretty cool solution.  http://www.vaistech.com/home.html

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That is awesome. However, 300 bucks for an input which you can make yourself for less than 50 is a little much. If it was 100 i would buy it in a second. However... i wish these people would have had the video/audio adapter before I bought mine a year ago.. theirs seems higher quality and better integrated. BTW, I think I used my DVD changer 5 times in the year that i've had it...

And to answer your question, I had it professionally installed... although I was just too lazy to do it. It's pretty straight forward... hook up into the OEM harness, and run the wires. I had the DVD changer installed under the cover in the trunk, where the spare tire should have gone... so when the cover is down, you can't see anything. Like I previously stated though, the sound is FM modulated, so it sounds like !Removed! - the solution that you have seems much better. If you can go with that, I would.

[LexInEffect]

does anyone have the picture of the install? When you intercept the lines, how do you reconnect them? did you guys use the electrical tape? Where can i buy the switch and the dc blocker?

[W6RU]

Mouser Electronics is a GREAT source for all electronic parts ....

http://www.mouser.com/

Terry

[Daveychan]

First, sorry for bumping such an old thread! BUT, this seems to be the best tutorial around for this "AUX hack"! (MUCH appreciation for the information posted here!)

So, the reason for this post, is that i'm a total dork and very nervous about doing this. (I've already tried a GROM adapter with no luck (Lexus SC430 - 2001 - Japanese indigenous/premiere model), so i'm returning that now and I'll give this method a shot.)

After reading through this several times, i've created a "layman's" wiring diagram for myself. I'd like to post this here in order to confirm that my information is correct.

Would you mind taking a look at it and correcting any mistakes i might have made? I'd hate to ruin my stereo because i didn't bother to check my plan with people who actually know what they are doing...

*** UPDATE: I have confirmed that this wiring is correct! I hope this helps someone else!