MSSS1 Aux input thread

[amkaos]

hi:
now that tim posted the msss manual, i ask:: would this help a smart guy install a aux-input?
thanx

[H_C]

Ahem, for the record, it was me who scanned the manual (in PDF) and sent it to Tim.

Yes, with this manual, you can create an aux in.

[timallen]

Well, I sure hope someone creates one soon!

I was looking at the schematics over the weekend, and I found a spot where I could interrupt the audio signal going from the CD player to the control amp PC board.

The wiring is up near the top of the cage, so it would be easy to tap into and provide wiring out the back of the unit.

The only thing is that you can't just select "CD" and then hear the signal from the aux input. It appears that a CD has to have been inserted to the tray mechanism for the unit to go into "CD" mode.

Humph....back to the schematics!

[H_C]

I'm working trying to use the DIN 13 pin Socket. Hopefully, I'll get it done by the end of this week.

If it works out well, it'll be much, much easier to mod in the future.

[timallen]

You know what?

Not all MSSS1 radios have the 13 pin DIN.

I have about 4 or 5 extra MSSS1 radios and the ones that were manufactured earlier on (late 1992) DO have the 13 pin DIN plug, but the ones made later on (into summer 1993 and beyond) DO NOT have the 13 pin DIN. They have only the one DIN plug going from the bottom unit to the upper unit. There's not even the extra 6 pin DIN plug on the back of the upper unit like on the earlier ones.

It's an interesting difference. The service manual applies to the original version (2 6-pin DIN plugs and one 13 pin DIN plug.)

Luckily, the MSSS1 in my car is the earlier version and is fully functional.

Please keep us updated, H_C!

[H_C]

The 13 pin DIN I'm referring is the plug that goes from the bottom unit to the top.
However, in doing it this way, the bottom portion would be unused (useless).

On the ones that don't have the 13 pin DIN, how do those connect to the lower portion (bs/amp unit)?

I might end up making 2 versions. One that uses the 6 pin DIN and the other, the 13 pin DIN.

The 6 pin version that I'll be making will only need 1 plug/input. However, doubt that this method would work, but I'll test it out tomorrow.

So far, there are 3 possible methods in creating an AUX in:
-the 13 pin DIN
-the 6 pin DIN
-using the wiring harness itself (by far the hardest, so I'm not going do to this route)

[timallen]

Well, from looking at the schematic, only two wires come from the 13 pin plug and go into the PC board on the bottom (BS) unit.

On my radio (and yours too, I would think), there are two 6 pin DIN receptacles kind of near the middle of the upper unit. The 13 pin DIN is near the left side edge of the upper radio.

Out of the two 6 pin DIN plugs in the middle, only the one toward the left side (nearest the white harness plug) is used, and then of course the 13 pin connector.

I was looking at the schematic and trying to figure out what's going on with the 13 pin connector. Only two wires come from it and connect to the PC board on the bottom, but why? From what I can see, it's only the LEFT channel audio signal

It's confusing me. I think, but I am not sure, it has something to do with the "WIDE" feature where the audio goes out of phase to "enhance" the experience.

Any ideas?

Oh, BTW, on the later radios, there is only the one 6-pin DIN plug from the top unit to the bottom and only ONE DIN receptacle on the back. The other 6-pin and the 13-pin DIN plug receptacles are not there. I'm not sure why or how they changed things because I don't have a schematic for the later version.

[H_C]

From what I can see, the white plug on the BS unit is only for headrest speakers.
The larger white plug powers up the entire unit and uses the door speakers.

I'm guessing the WIDE feature gives the tweeters an extra boost in sound?

Since my 93'C didn't come with a MSSS system, I don't have a transducer unit nor do I have tweeters. So, I'm just guessing what exactly the WIDE feature does...

In any case, whatever method I'll be using, it'll make the bottom portion unused (at the moment).

[H_C]

Hey Tim, could you take a picture or two of the different versions?

I think that way, it'll be easier and a lot faster to understand the situation.

[timallen]

Originally Posted by H_C @ Fri Jun 22, 2007 12:18 am

From what I can see, the white plug on the BS unit is only for headrest speakers.
The larger white plug powers up the entire unit and uses the door speakers.

I'm guessing the WIDE feature gives the tweeters an extra boost in sound?

Since my 93'C didn't come with a MSSS system, I don't have a transducer unit nor do I have tweeters. So, I'm just guessing what exactly the WIDE feature does...

Actually, the BS unit (bottom one) powers the transducers and the front speakers.

The smaller, less powerful amp for the HR speakers is built into the top unit.

I was playing around with the balance, fader, and WIDE feature today and I discovered that when the WIDE feature is off, the balance does just what you would think - it shifts the sound on the left and right. I noticed that when the fader was all the way to the HR speakers and I turned ON the WIDE feature, the same signal was in both HR speakers, no matter which way I turned the balance. However, the one side is out of phase, thereby fooling the ears to seem like the sound is enhanced.

[timallen]

Originally Posted by H_C @ Fri Jun 22, 2007 12:19 am

Hey Tim, could you take a picture or two of the different versions?

I think that way, it'll be easier and a lot faster to understand the situation.

Well, I put my stereo back in the car, but I might have another one around here with the 3 DINs.

I have the older version sitting right here.

Let me see what I can do here in the next few minutes - after I take a smoke break.

Thanks for working with me on this!

[H_C]

Tim are you sure the BS powers up the font speakers?

http://forum.miata.net/vb/attachment...chmentid=26045

On the manual, it clearly states that the smaller plug powers the head rest speakers.

I really, really hope the UPS man gets here tomorrow or Saturday! My next mod would to install a USB port to charge my MP3 player.

[timallen]

Oops, sorry. I got that one mixed up.

Anyway, here are the pics.

[H_C]

Okay, that clears things up a bit.

When my parts come in the mail, I'll start working on the 6 pin version.

[timallen]

Originally Posted by H_C @ Fri Jun 22, 2007 1:06 am

Okay, that clears things up a bit.

When my parts come in the mail, I'll start working on the 6 pin version.

Sweet!

Wanna fill me (us) in on what you're up to?

[H_C]

What do you mean what I'm up to? I'm working on the aux input

Anyways, according the schematics:
- Pin 1 is ground
- 2 is right channel in
- 3 & 6 ? (I'm not sure yet)
- 4 Left channel in
- 5 ? (not sure either)

Looks like I have my work cut out for me. Wish me luck. :wink:

[timallen]

Good luck!

Interrupting the audio signal at the DIN is fine to get the audio output to the bottom unit for the transducers and HR speakers, but what about the door speakers? :shock:

Confusion is setting in for me after staring at the schematics for a few hours.

[H_C]

Tim, I think you need to go out for another smoke.

The 6 and 13 DIN plugs won't interfere with any of the speakers. It will however, make the BS completely useless.

[timallen]

Originally Posted by H_C @ Fri Jun 22, 2007 1:33 am

Tim, I think you need to go out for another smoke.

The 6 and 13 DIN plugs won't interfere with any of the speakers. It will however, make the BS completely useless.

But, but....

Going on my limited skill of reading schematics, I thought the audio signal was routed to the lower unit via the 6-pin DIN plug for processing and amplification for the transducers and HR speakers. No?

Oh hell, it's late. I must sleep. More on this tomorrow.

[H_C]

Hmmm, I need a breather too. More of this tomorrow.

[H_C]

Bad news, using the 6 pin or 13 pin DINs, won't work.
The only way to get it working is to open up the radio and do some major wiring (which is not worth it at all).

Apparently, you can't just plug in wires. You need resisters and some other chips for an external mod.

I'm sorry Tim and everyone else, but I've given up. My fingers are bleeding, greasy, and numb. I've poured my sweat and blood into this, and all I have to show for this is failure.

[timallen]

Well, I for one, appreciate all of your effort.

I will look more into this and see if there is anything I can do.

[H_C]

Thanks for understanding.

Again, sorry I couldn't find a solution.

[timallen]

Originally Posted by H_C @ Sun Jun 24, 2007 5:27 pm

Thanks for understanding.

Again, sorry I couldn't find a solution.

It's ok. I am determined to make this work!

I know another guy from Miata.net that is working on this. I'm not sure he's on here, but I will keep eveyone updated.

[H_C]

By the way, I'm selling off the manual.

[timallen]

Yeah, I saw that.

Make sure to post it here too:

http://autos.groups.yahoo.com/group/93LE/