Adding an aux input to a factory Volvo stereo

Lazarus said:

Is it likely that my DIN cable pinout is the same as in the first post?

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I'm not sure, but you can remove it from the vehicle and test with a multi-meter to see what's going on. If the wires are looping back internally (and output hooked to an input inside the cable), perhaps you can cut it short and solder these wires together for the same effect. Ultimately you'll have to investigate exactly what's going on with a multimeter.

Lazarus said:

I see that the OP has an IPOD, and I understand that they do have a line out feature. Other MP3 players do NOT have a line output, which leaves the headphone output as the only possibility. It works to some extent, but does not produce great audio quality unless an intermediate amp/EQ is employed.

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I am using the headphone output, not any line out from the ipod connector itself.

I don't totally understand what you're saying, but the ipod headphone connector seems to be equivalent in power to the built in radio input, on approximately half volume the way I have it wired up. It sounds pretty good: I'm no audiophile but I don't detect any major distortion.

It is not missing the bass as you suggest it would be, but it *does* miss the bass if I wire the ipod output directly into the stereo (in place of the equalizer), instead of as input to the equalizer. Perhaps the equalizer itself contains an internal pre-amp?

can you do this if your 740 does not have a equalizer?

IPOD and Line Out

I don't own an IPOD, but my searching reveals that they have a true line output. Take a look at how many products feature an IPOD docking station connected to a small radio or other amplifier. Those connections are of course part of the world's crummiest connector on the bottom of the unit. I'm almost certain you can get a plug for IPOD use in the car, with line outputs already broken out and ready to plug into your existing stuff.

Now the why. The audio output of an MP3 player is highly EQ'd so that the earpods sound good. They specifically match an earpod's quirky, and by most measures terrible, acoustical output. The earphone out is relatively low impedance maybe 30 ohms, I don't remember. The 2 combined above facts make the audio from the earphone out less than satisfying when used to drive a line input. The line outs on your IPOD are not EQ'd - that happens in the amplifier, and the impedance is correct for plugging into line inputs.

Obviously, you found out your hookup works. But since you have line outs, you will be amazed at how much better they sound if you use them!

Lazarus

I'm wondering if someone could tell me how to perform a similar modification on my '97 960 radio. The factory setup is equiped with the option for a Volvo external CD player that, from what I've been told, uses a BUS-type cable connection.

Any ideas?

Wren said:

I'm wondering if someone could tell me how to perform a similar modification on my '97 960 radio. The factory setup is equiped with the option for a Volvo external CD player that, from what I've been told, uses a BUS-type cable connection.

Any ideas?

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I use my Samsung Rugby II phone for music on my '97 960.

I have 175 CD's loaded into it, and room for ~60 more full length CD's, not just songs.

How did I connect it? Amazon, Sony tape pick-up $10, and a USB micro to 3 mm mini cable, $5 which also has a microphone for hands-free.

FYI, scrap using the MP3 format, (iPods,, too) instead use .wmv files, better compression, better sound quality and can hold more information about artist, album, songs and graphics, which is all downloadable as you load the albums automatically from Windows Media Player through the internet (music directly from the CD, other info off the internet), takes ~2 1/2 min per album, and a couple seconds to drop & drag into the phone's chip as the computer see it as a 16 Gb hard drive.

I have had my head unit apart looking for a way to do this and since it is an integral amp/reciever/CD/tape player, it is not as easy as the '91 245 with the separtate amp. There is no line-in connections. I still use the tape pick-up on the
91, too, as it is the simplest and best sound, and the hands-free phone operation is the way to go.

Could have bought a mp3 cassette?? Exelent work any ways

Cassette adapters sound terrible, and don't work in this stereo for some reason.

I invented the cassette tape input adapter. The first one was a hand-coiled electromagnet inside of an old gutted cassette I made when I was 6 years old and worked pretty damn well, but (just like the current ones on the market) not nearly as well as a direct line in. Sony filed and got US patent #5307326 on it about a year later. It may have been a pretty obvious invention at the time (after cheap car CD players become available), and made by many people concurrently...

http://www.crutchfield.com/s_500CDA105/Alpine-CDA-105.html?tp=5684&nvpair=FFBrand|Alpine


http://www.crutchfield.com/p_500KTP445/Alpine-KTP-445-Power-Pack.html?tp=115&nvpair=FFBrand|Alpine

This is the set up I have in my wago. Sounds awesome, removable faceplate, cheap..and its an alpine so you cant beat the quality. And the other lil alpine i got is a 180 watt mini amp that plugs into the back of the deck.. So 200 watt deck...180 watt amp...380 watt.. Sounds awesome Way better than rockin a stock 20 something year old deck. Im gettin a new camera next weekish so if any one wants to see this set up or hear it though a vid, I'll get it done.

casioqv said:

Cassette adapters sound terrible, and don't work in this stereo for some reason.

I invented the cassette tape input adapter. The first one was a hand-coiled electromagnet inside of an old gutted cassette I made when I was 6 years old and worked pretty damn well, but (just like the current ones on the market) not nearly as well as a direct line in. Sony filed and got US patent #5307326 on it about a year later. It may have been a pretty obvious invention at the time (after cheap car CD players become available), and made by many people concurrently...

Click to expand...

The tape pick-up's of old are not nearly the sound quality that a new one has. I know because I have a 25 yr old Sony tape p/u that I used with the orig Sony Discman. I researched the tape pick-ups and found that the current Sony has extended frequency range and equals the CD quality, way better than the other out there. When compared to the old one it is like night & day.
The 960 Premimum sound is pretty darn good from the factory as long as the speakers are in good shape, way better than the 200/700 decks of the 80's, and the sound from the Rugby II with pick-up is nearly the same as the CD which it was ripped from. Excellent sound. I can say the same about the p/u when put into my Kenwood head unit and Phoenix Gold amp in the 245. I have played CD's back-to back and can't tell a difference in most cases, especially with modern recordings. Older recordings that were first coppied from tape masters or vinyl show a little loss, but not anything to complain about.

Back on track.

Years ago I went to the trouble to tie into the separate amp Volvo stereo's come with by making a custom DIN plug/wiring harness and add a line-in for hooking up an aftermarket head units as well as a CD changer. It is a PITA and not worth the effort. I still have a bag of DIN plugs and pins as well as RCA jacks if anybody wants them. I think I have the schematic for the '91-93 240 stereo amp which isn't easy to find.
It's far simpler (if not better sound, too) to get a complete aftermarket stereo w/built in amp or just get the tape pick-up and an MP3/music player.

I tried this with the line out from an ipod and it doesn't work too well: the line out has too strong a signal and you have to keep the volume on the head unit almost all the way down, and the bass clips. The headphone output on half volume has the best sound quality I've been able to get from it.

Also, I'm very impressed how good the stock 760 stereo sounds through brand new Pioneer speakers...

I am trying to figure out if I could do this without the EQ. It seems like you could. Also I notice my HU has a button marked CD, so I assume that'd have a line in.

No EQ - More Info

I everyone --

I know this is an old thread, but, hey, we all love our "old" cars.

I wanted to bump this. Does anyone have any information on doing this in a vehicle that does not have an EQ, only the CR-814?

I've got the same question as jeffreyc.. I've got a cr814 with a tape player that won't let me put a tape in. If it did I'd just use the adapter Ibe got. Yall think I could take it apart and clean it or something? I'm redoing the entire stereo in about 6 months but want something to play more than just the radio. Thanks!

Works with any radio with a standard antenna port. Interrupts the aerial signal when switched on. Anything connected to the audio in port place through the radio.

I've had it for a year and it works well.



http://www.amazon.com/gp/product/B004613FCE?&psc=1&redirect=true&ref_=oh_aui_search_detailpage

My aftermarket Pioneer is acting up so I decided to take a CR-814 apart to have a look at how the EQ line out works...

This is the pinout:
Pin 3 is L in on the head unit main board
Pin 1 is L out on the head unit main board
Pin 5 is R in on the head unit main board
Pin 4 is R out on the head unit main board
Pin 2 connects to S ground (speaker ground)

6, 7, and 8 are not used.

The OP's method of adding an AUX jack should work - just run the left side between pin 3 and pin 1, the right side between pin 5 an pin 4 and the speaker ground obviously to pin 2. When nothing is connected, pins 4/5 and 1/3 will be jumped just as if the plug were still there. I would recommend fabbing up a cable from scratch because I have no clue what could be scavenged that would fit the plug.

I would like to try but can't because the CR-814 I have has a triangular shaped bezel so it doesn't fit in my 960. It must fit only 940s. If anyone has one with a flat front I would be happy to build the cable and report back

The connector on the bottom attaches this board to the main board in the radio. You can see the circular shape the plug to the EQ takes above it.


This is the main board. The connector to the smaller one that the EQ and amp plug into is at the bottom/center.

I'm trying a different approach on my TD-6141 with no external EQ, and thought it might be useful to bring this thread back.
I have removed the cassette player 'works' from my radio. it comes out as a unit that has 4 wire connectors going to the main radio. One of those is a 3 wire connector for audio, L-G-R. There are other connectors for supplying power and controlling the tape functions.

A quick and dirty test proved that I could send audio from my phone's headphone jack to this point, and it would play. That connector is apparently expecting a very low level signal from the tape deck though, anything above the lowest volume on my phone causes distortion.

Then I tried to figure out how the audio source was switched. There is a little switch in the back of the tape deck that gets triggered when a tape is inserted. After some trial and error i found that closing the connection between the 'keep' and 'tb1' terminals on 2 of the connectors seemed to do the trick.

I bought a micro switch and mini jack from Radio Shack and tried my first pass at it. I switched the 2 terminals mentioned above, and wired up the jack to the audio connector. It works, I can switch the audio source and play through the phone, but it is very noisy. All kinds of static and background noise even without the engine running. Clearly there must be more to it, so I need to do a bit more trial and error. Worst case, I blow this thing up and just put an aftermarket in.

Photos to follow if I get this thing working right.

The shared ground is causing the noise. Your headphone jack is stereo not mono

Well, I got it done and working to some extent, all for about $10. I grounded the audio jack to the radio chassis. It is hard to describe, but the phone seems to switch its audio output on and off when it is not doing something that makes sound. When it is off, I get ground noise still. When the phone is playing music or other audio, the noise mostly goes away and the sound is much clearer. If I throw the switch with nothing connected at the jack, sometimes I get noise, sometimes I don't.
When the music is playing it still sounds a little like it would if you were playing an old school cassette. It is a 'warm' sound like you get out of old audio equipment. I'm not sure if this is just due to the preamp circuitry or the way I connected things. It doesn't sound bad, it just sounds like it music did back in 1990.

I think I need a couple of things to really get it right:
1) Some way to isolate the ground noise. Maybe something like the HiFimeDIY DAC that can plug into my USB port and also isolates the ground and any voltage from the phone.
2) Some app or hack that can let me better control the audio output from the phone itself. The headphone jack is already somewhat amplified for headphones and also has funky EQ designed for tiny earbuds. That could be contributing to the overall sound I get too.

The red circles show the spots where I wired my switch and the audio jack. Note that the radio is sitting upside down here. The circuit board you are seeing is on the top of the unit facing down.


The switch connects the 'keep' terminal, which has 12v on it:


To this terminal, TB1:


This is the audio connector for the cassette deck. The 2 pots to the right of it control the level of the output. They do not seem to control 'gain' or sensitivity of the input, they only control the volume of what is coming out of the cassette's preamp circuitry. This lets you tweak it so that the sound level is the same between the cassette input and normal radio.


I used 2 of the cassette button holes to accommodate the new additions: