Johnny_Cracker

iTrader: (1)

I've been deciding on where to input a signal allowing me to retain function of the stock tuner and eq... Reviewing the FSM I decided to just bypass the preamp out from the deck leading to the eq, so I needed the din pinouts. After looking at the diagram I found something interesting in the tape deck din cable pinout:


...notice the INPUT leads? Nothing loops thru the deck does it? I surely can't think of a reason why unless there's some kind of capability to input a signal. This was before the need for aux inputs, so maybe it's a feature used to inject a signal for testing the unit???

Looking at where the cable would input the eq reveals another interesting fact:


The lines labeled INPUT on the deck cable pinout are listed as NOT USED on the eq din input. So the eq isn't sending it anything, which it has no business doing anyway...



Comments? Thoughts?
I'll be trying to input a signal on these eventually. I'll post what I find out.

Starfox07

The wiring on the stock stereo is such a mess :/

RX-7 Chris

iTrader: (19)

Interesting. I'd like to hear what you figure out.

wmelon137

I believe the previous owner of my gsl-se use this exact input to hook a remote cd changer into the radio system, as it requires the radio to be in tape mode.

I'll look through the wiring diagrams he gave me when I get home tonight.

DerrickS

I can't think of a reason why a deck would have INPUTS on it. Maybe for testing as you say. Hmmm...

Do you have to tell the HU to switch over to the tape deck, or does it do that automatically when a tape is inserted?? I don't have a stock stereo, so I have no clue.. Reason I ask is that I was going to convert the input signal from my old CD/AM/FM player to take an mp3 player from the CD input to the internal amp, but I got to thinking that the source switches automatically, and I didn't know how to hard wire it to be on the CD without a CD being in the deck.

DerrickS

Ha... WMelon just told me the answer to the above... Nevermind. I am going to say that you can run an input into that puppy.

Johnny_Cracker

iTrader: (1)

IT WORKS!!!!

Yes my friends, you can in fact input a signal straight from an iPod into that fukr and it sounds good!... considering the following:

It injects the signal over whatever is being played.... radio + iPod = roughly 50/50 mix radio to iPod audio. Tune to a quiet channel (AM 1600+ works well for me) and it's certainly tolerable to say the least.

Insert a tape and all you'll hear is the tape mechanism noise (radio noise off) + sweet aux-in audio goodness. I'd probably use this at speed since the road noise will negate the mechanism noise or if I lived in the city and had few quiet radio channels to tune to.

I wired in the original aux-in idea as a backup in case the inputs were bullshit (I tapped into the preamp outs the deck would send the eq). It turns out to sound indistinguishable from audio ported thru the newly discovered input.

Truely Good Things!!!

I took a bunch of pics on my BS Pantech camera phone since my point and click is mia. I'll try to get them up. This IMO was very simple to do and required only an audio patch cable to hack, some electrical tape, a razorknife and wire stripper.

I'll post the wire color codes vs pin too. That'll save you cutting them all and checking with a multimeter to see which pin is which color .

I'm also doing an amp swap and have similar din-hacks I'm working on.


You can still use the tape deck too!!! I switched back and forth from the tape adapter and new aux input and the aux was noticeably cleaner and fuller!

Johnny_Cracker

iTrader: (1)

KansasCityREPU

iTrader: (9)

Would there be any way to make a pigtail that replaced the cassett DIN? This way no noise.

Johnny_Cracker

iTrader: (1)

There's no new noise in the system so I don't think replacing the cassette din would do much more than remove tape function. Ideally we need a way to trick the tuner into thinking a tape has been inserted without actually inserting one. When a tape is inserted the radio section is completely muted which leaves us the clean channel to inject over EXCEPT for the tape hiss. The radio IS NOT muted when I use the new inputs or the tapped original deck outputs without a tape inserted.

**I'm not so sure this isn't a matter of preamp voltage mismatching** the tuner might require a higher source input voltage to switch off the radio than the iPod is putting out. i.e. the tape preouts are higher voltage... I should be able to check the voltage easily since I've tapped the original deck preouts. If so I'll have to come up with a simple adjustable preamp...


Also tested the amp swap using the factory din hardware and it works great. Only change is a better ground to chassis instead of back thru din cable ground.

iowa_hawk1

iTrader: (4)

[QUOTE=Johnny_Cracker;10755133] Ideally we need a way to trick the tuner into thinking a tape has been inserted without actually inserting one. When a tape is inserted the radio section is completely muted which leaves us the clean channel to inject over EXCEPT for the tape hiss. The radio IS NOT muted when I use the new inputs or the tapped original deck outputs without a tape inserted.QUOTE]

Couldn't you just insert an empty cassette shell into the deck? With no tape running over the heads tape hiss should be zero.

Johnny_Cracker

iTrader: (1)

Sorry.... middle aged with kids and all. A long time since checking thread. Regardless, YES! that's a good idea I STILL havn't tried yet.

I'm gonna finally be rotating back to the stereo again this weekend and might jack the mother in law's tape adapter to find out. If you haven't already found out in the YEAR PLUS it's taken me to reply to you!!!

Johnny_Cracker

iTrader: (1)

Also I hope to wrap this up and make an easy to follow tut as I've realized this is a bit confusing.

Thanks to NielRX7 btw... good PMs.. I'll have to ask him if I can post them.

iowa_hawk1

iTrader: (4)

I knew there was a reason I didn't have kids.

Johnny_Cracker

iTrader: (1)

... So I stripped down a casette tape adapter into just a plastic shell. Without the tape head engaging anything it does sound cleaner, but discovered the tape hiss was just a small part of the overall background system noise.

The noise is only audible with no source playing and the volume cranked. It's certainly clean enough to live with and not noticeable when playing from my iPhone.

So the result is an easy way to disable the tuner and provide a clean channel for the aux-in mod to piggyback.

Now back to the important issues like cleaning the TB, Dynamic Chamber and BAC to fix (hopefully) the idle-seeking issue I've been having. Recently rebuilt steering linkage with good results.


'85 SE All cleaned up. Currently 54k original

iowa_hawk1

iTrader: (4)

Glad to have a good idea every now and then. That is one beautiful SE you have there. Where did you get the clear marker lights? I have never seen those before.

Johnny_Cracker

iTrader: (1)

Thanks Hawk, I don't have the link but am pretty sure I found the tut here about it. I think I searched for "clear sidemarkers" when I originally found it.

Here's the basic rundown as I learned from the tutorial:
I pulled the taillight assemblies and popped them in the oven to soften the adhesive holding the outside acrylic to the main housing. A little bit of patience will result in popping off the outside acrylic (without cracking it) giving access to the red and orange colored plastic inserts.

I removed those and used them to make templates on a flourescent light diffuser sheet I got from a local hardware store. I used a large soldering iron to melt out the patterns since cutting that stuff can suck. I replaced the colored inserts with the diffuser and sealed the assemblies back up.

I had to buy LEDs to replace the bulbs so the colors are proper. Thankfully I had a buddy (now deceased ) that whipped up some resistors for me so they didn't hyper-flash or light my BREAK light on the dash.

The stock red square central reflectors I carefully pryed out and replaced with white driveway reflectors melted and sanded to fit.

The sidemarkers were done much the same way except were much easier, and I doubled them up for better effect.

I'm really happy with the results, was a little worried it'd look cheap.

iowa_hawk1

iTrader: (4)

So you are using red and white LEDs in the tail lights and orange LEDs in the sidemarkers?

ioTus

iTrader: (5)

Wow, I've been planning out this mod to do in the next few weeks - auspicious you rez'ed it right now.

One thing I was considering was busting open the tape deck portion and disabling the power wire to the tape motor, that will eliminate the motor noise.

I'd be curious to see how you're switching sources - I'm wondering if there's a way to trigger the radio to turn off without having to use a blank tape.

I will be acquiring a stock head unit soon to do this mod, and have some excellent camera equipment, so we should team out efforts on the tutorial.

Interesting you mention the clear tails tutorial - that very well may have been the one that I wrote I have simplified and refined the method greatly, its not nearly as complex as i make it look there. I need to re-do that as well.

ioTus

iTrader: (5)

Oh and Johnny - what amps are you running? I'm planning on a 5 channel amp with speaker level inputs to avoid having to use line-level converters.

How much line noise are you noticing, and does the Dolby NR (noise reduction) make a diff? It's very possible that is only active through the tape signal and not the aux input, as that's what the technology was designed for.

sevens4me

iTrader: (1)

I've been meaning to permanently install/integrate an aux. input into my stock radio forever. You can tap into those unused inputs or the tape mech.'s inputs and it does sound good without a ghost signal, or tape mech. noise. To shut the radio down, and accept the "tape"signal into the amp, there is a little switch inside the tape deck with blue and yellow wires. It looks like when a tape is inserted, it breaks the connection the switch has when empty, and kills power to radio. You could just chop off this switch, extend the wires to wherever you wanted, and put a simple on/off switch. Then when you want to use the input or listen to a tape, just flip that switch to take it out of radio mode. You could also figure out what happens when a tape is inserted to activate "tape" mode through the DIN cables. I don't know if a +12V is sent somewhere, or a connection to GND is made. I originally thought an unused DIN port on the back of the radio was for an input, but I eventually realized there is a front out, and a rear out, to go to the two amps...BUT if you have the joystick, only the front out is used, then the joystick splits to the two amps. As far as adding your own amp, couldn't you avoid speaker level inputs? I mean, the signal in the DIN cables is pre-amp, so can't you just wire on RCA plugs from the DIN? I'm including horrible pics of the afore mentioned switch...

ioTus

iTrader: (5)

Hmm yah, thinking about it i suppose you would use speaker-level only if you were coming off the factory amps, which would be replaced in this application, so RCA from the DIN makes sense. Would love to see some photos or detailed descriptions of the the setups described above!

And excellent tip on the radio kill switch. I wonder if there are signal activated switches, so when a sound signal is sent through the aux cable it trips the radio off.

sevens4me

iTrader: (1)

I'd like to do it proper-like and fiqure out how to activate the tape mode via the interconnected DIN cables. But I don't have a bench setup, and it's HARD to do testing in car as the harnesses to connect the radio aren't long at all. There are fancy pantsy switches to send a signal when audio detected, but there are also simple switches like a headphone input jack with a spring loaded contact on the end so that the end of the jack when inserted, breaks that connection as long as it's plugged in. I was really surprised how good my mp3 sounded run through the stock EQ setup, but the stock speakers leave much to be desired. Unfortunately, unless you're upgrading to more modern amps while keeping the stock radio, I don't see many viable affordable replacements for the stock speakers, because they require/receive such low power. I can't find modern replacements that will work well with that low rms requirement...

Rotor_Venom08

iTrader: (3)

just buy one of these mount the switch, and aux port. and call it a day. its hard wired and wont interfere with any noise and has its own switch without tearing apart a 30 yr old tape deck for no reason. your welcome.

ioTus

iTrader: (5)

Veerrrrry interesting. Great reviews on it too. I'm not seeing any high-end hifi owners chiming in though.

Even more interesting for my application:
TranzIt USB IS32 - Universal Car Integration Kit for Smartphones, MP3 Players



Same basic module only with USB charging and backlit power button. I'm liking this. This would be worth a shot.