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Adding an aux input to a factory Volvo stereo

casioqv

Mad Engineer
Joined
Feb 23, 2003
Location
NorCal
This is for the factory Volvo stereo with the EQ-2111 graphic equalizer (as my 1984 760 has). This mod retains all of the factory functionality, and let's the volume, balance, and fader controls on the factory head unit adjust sound from your iPod or other device. The sound quality is excellent!

Parts needed:
-1/8" stereo normally closed panel jack (radio shack p/n 274-246)

Wiring pinout in the 5-din connector of the EQ-2111 equalizer:
red: right + to amplifier (sound out from EQ)
white: left + to amplifier (sound out from EQ)
black: common audio ground
yellow: left + input (sound out from head unit into EQ)
green: right + input (sound out from head unit into EQ)

Wiring for 6 pin 274-246 radio shack jack:
1: connect to audio ground (black wire from 5 din)
2: connect to cut yellow wire on equalizer board
3: to input yellow wire from the 5-din connector (sound from stereo right)
4: to input green wire from the 5-din connector (sound from stereo left)
5: connect to cut green wire on equalizer board

Pinout for 6 pin 274-246 radio shack jack:
picture.php


You just need to "intercept" the yellow/green wires inside the equalizer with the panel jack so that when the headphone jack is disconnected it passes through as normal, and when you plug in your device input is taken from it instead. You do this by cutting the yellow and green wires inside the unit and wiring each end of the cut portion to the audio input jack.

The panel jack itself can be mounted on the plastic faceplate of the equalizer in the upper right corner just where there is no metal backing plate (middle of the Volvo logo).

Pics:
picture.php

picture.php


I suspect that this mod will also work on other models of Volvo equalizer, although the wiring might be slightly different. I think you could also wire up RCA inputs and outputs if you wanted to use this equalizer/aux input between an aftermarket head unit and aftermarket amplifier, although you'd be limited to 2 channels.
 
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Interesting information, but the quality will not be anywhere near as good as modern 4x50 headunit which also has a CD and ipod connecter rather then aux.

But it's great if you want to have a concurs standard Volvo.
 
Interesting information, but the quality will not be anywhere near as good as modern 4x50 headunit which also has a CD and ipod connecter rather then aux.

I doubt that... especially if you happen to have the large 2x60 Mosfet HA-5161 amps (a la 780). It's simply not physically possible to fit that kind of hardware into a 1 din head unit. I really doubt that any so called "4x50" head unit produces even a significant fraction of 200 watts RMS. Even the lowly 4x20 watt amp probably easily compares to the most expensive 1 din headunits.

Some reasons I can see to use a factory 760 stereo with an aux input:
-Extremely high quality ergonomically placed controls with great tactile feedback, and just overall high quality construction
-Looks stock and won't be a theft target
-Aftermarket stereo installs tend to reduce car value, especially once they're considered "old"
-Probably already installed and working in your car
-Backlit controls are easy to operate in the dark, but don't add tons of ambient light like modern stereos with huge flashy screens
-This is literally a $2.49 modification vs whatever a top quality modern head unit costs (I assume considerably more)
-I just want to listen to some low bitrate pirated mp3s in my noisy as hell 26 year old car- not exactly an ideal listening environment for the discriminating audiophile

I've bought expensive head units about 4 or 5 times for Volvos, and always had the windows broken and the units stolen within months, even if I took the faceplate with me. I've *never* had a car with the stock stereo broken into once.

Most importantly I'm a luddite and despise anything even remotely modern :-P
 
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I doubt that... especially if you happen to have the large 2x60 Mosfet HA-5161 amps (a la 780). It's simply not physically possible to fit that kind of hardware into a 1 din head unit. I really doubt that any so called "4x50" head unit produces even a significant fraction of 200 watts RMS. Even the lowly 4x20 watt amp probably easily compares to the most expensive 1 din headunits.

Some reasons I can see to use a factory 760 stereo with an aux input:
-Extremely high quality ergonomically placed controls with great tactile feedback, and just overall high quality construction
-Looks stock and won't be a theft target
-Aftermarket stereo installs tend to reduce car value, especially once they're considered "old"
-Probably already installed and working in your car
-Backlit controls are easy to operate in the dark, but don't add tons of ambient light like modern stereos with huge flashy screens
-This is literally a $2.49 modification vs whatever a top quality modern head unit costs (I assume considerably more)
-I just want to listen to some low bitrate pirated mp3s in my noisy as hell 26 year old car- not exactly an ideal listening environment for the discriminating audiophile

I've bought expensive head units about 4 or 5 times for Volvos, and always had the windows broken and the units stolen within months, even if I took the faceplate with me. I've *never* had a car with the stock stereo broken into once.

Most importantly I'm a luddite and despise anything even remotely modern :-P
I took the easy way out. No head unit at all. Just an 1/8-inch cable connected directly to my amps. Plug iPhone in, play a song, and I'm happy. I'm quite sure no one will steal a gutted head unit that is simply lined with padding and automotive carpet.
 
kinda a cool mod...

got way too elaborate a aftermarket radio in my 242 and wanna go back to something simple and basic. this'd be cool if it were for a radio, sans equalizer...nowhere to put that conveniently in my dash.
 
this'd be cool if it were for a radio, sans equalizer...nowhere to put that conveniently in my dash.

If you have a radio old enough that it has a mechanical potentiometer (I think most RWD Volvo factory stereos) for the volume control, than you should be able to wire an aux jack by intercepting the sound from the preamp into the volume potentiometer.

Newer stereos with digital volume control I find too confusing to figure out where/how to wire the aux input internally.
 
If you have a radio old enough that it has a mechanical potentiometer (I think most RWD Volvo factory stereos) for the volume control, than you should be able to wire an aux jack by intercepting the sound from the preamp into the volume potentiometer.

Newer stereos with digital volume control I find too confusing to figure out where/how to wire the aux input internally.

you already lost me...i'm not one for electrical problems...let alone electronic.
 
I doubt that... especially if you happen to have the large 2x60 Mosfet HA-5161 amps (a la 780). It's simply not physically possible to fit that kind of hardware into a 1 din head unit. I really doubt that any so called "4x50" head unit produces even a significant fraction of 200 watts RMS. Even the lowly 4x20 watt amp probably easily compares to the most expensive 1 din headunits.

Some reasons I can see to use a factory 760 stereo with an aux input:
-Extremely high quality ergonomically placed controls with great tactile feedback, and just overall high quality construction
-Looks stock and won't be a theft target
-Aftermarket stereo installs tend to reduce car value, especially once they're considered "old"
-Probably already installed and working in your car
-Backlit controls are easy to operate in the dark, but don't add tons of ambient light like modern stereos with huge flashy screens
-This is literally a $2.49 modification vs whatever a top quality modern head unit costs (I assume considerably more)
-I just want to listen to some low bitrate pirated mp3s in my noisy as hell 26 year old car- not exactly an ideal listening environment for the discriminating audiophile

I've bought expensive head units about 4 or 5 times for Volvos, and always had the windows broken and the units stolen within months, even if I took the faceplate with me. I've *never* had a car with the stock stereo broken into once.

Most importantly I'm a luddite and despise anything even remotely modern :-P

Thanks for the tips. I really like the basic functionality and lack of attention of the factory radio. Living 2 blocks from a very large low income housing project flashy stereo components is risky. That and I have a couple of equalizers and an extra 2x60 amp and back shelf speakers I have been wanting to plug in to run with the 4x20 amp running the 4 door speakers. Now I can easily listen to Pandora in the car at appropriate volumes.
 
You must live in dodgy area's if you get your middle range stereos stolen from your Volvo, I have to say it's not very common for stereos full stop to go missing unless they are the latest and greatest.

I upgraded my headunit from the late 760 amp and headunit with a pioneer one years ago, the sound quality instantly improved, mostly as all those systems only half work in the first place. And in my 740 too, sounded so much better with just a headunit change. And I do use cd mp3's so I needed the headunit to listen to music.
 
This mod does work very well to add the capability of playing virtually anything with a headphone jack through the factory sound system - I have done the same thing with a cr-814 radio and an external EQ and have been using it for a couple of years now - sound is great and the cr-814 also is able to control a trunk mounted cd changer for even more music versatility.

But it's not necessary to have an external EQ attached for this to work - although the EQ does improve the sound of the system. You can simply attach the phono headphone jack to a cable connected to the EQ din jack on the back of any of the volvo labeled alpine made radio headunits that have a EQ jack on the back. I have them in both my 240's and my 740 and have sold several to others! It's pretty simple to solder up a cable - on my 240's I mounted the jack in one of the blank toggle switch spots - makes a nice clean convenient installation. I think I still have a couple of extra cables made up if someone wants one - for $15 I'll dig them out and mail it! :)
 
But it's not necessary to have an external EQ attached for this to work - although the EQ does improve the sound of the system. You can simply attach the phono headphone jack to a cable connected to the EQ din jack on the back of any of the volvo labeled alpine made radio headunits that have a EQ jack on the back.

I tried that on this specific stereo before adding the jack inside the equalizer, and it worked but the bass was almost entirely filtered out and it sounded really terrible.
 
I tried that on this specific stereo before adding the jack inside the equalizer, and it worked but the bass was almost entirely filtered out and it sounded really terrible.

Don't know why it would have done that - I have one on a cr-814 without an eq and one with an eq - and both sound great. I have also done this on several other volvo factory decks including the td-6141 and even a cr-2170 which is an older (early 80's) lower slot factory AM/FM/cassette radio that still had the manual pushbutton presets (and an eq jack on back) without using an eq -

In my opinion, for a pre-91 240 (91 is when the speakers began to be fed directly from the external amp IIRC) the cr-2170 in the bottom slot fitted with one of these external jacks for an mp3 player is the ultimate "factory original" plug and play sound system - and it frees up the upper dash slot for some cool gauges too!
 
Very coll mod, very well done. For a quick, non expensive mod its great. I too replaced my head unit and I can for a fact tell you that the replacement head unit did make a big difference... Now that being said all props to u for the mod. I just need more than that and my MTX system kicks @SS!!!!!

As far as being stolen....I leave the keys in the car, sometimes in the ignition.....
 
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Don't know why it would have done that - I have one on a cr-814 without an eq and one with an eq - and both sound great.

The only answer I can think of is that the equalizer itself distorts the sound (increases bass) even when set totally flat and either the head unit or amplifier are configured to compensate for this. So if you just bypass the equalizer entirely, most of the bass will be filtered out.

For Volvos without a stock EQ do they have some sort of "loopback plug" that jumps the pins together where the equalizer would normally plug in?
 
For Volvos without a stock EQ do they have some sort of "loopback plug" that jumps the pins together where the equalizer would normally plug in?

Yes, that is exactly what they have - just a simple jumper plug.
 
Loopback plug

My 940 came with a factory CD player (player in the trunk). Now that I tossed it, I have to keep the DIN cable plugged into the radio for it to work, although it doesn't make sense to me why that is so. Nothing connected to the other end of the cable. Is it likely that my DIN cable pinout is the same as in the first post? I'd like to get rid of this 10 foot cable on the floor!

thanks!
Lazarus
 
Line Level and EQ

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. The car's EQ unit operates at audio line level (about 1 volt p-p, at 5K-10K impedance) so unless the EQ is faulty, the bass distortion is coming from the speakers themselves which are not able to pump out the necessary bass frequencies. In a normal home stereo, the speakers are restrained by physical or acoustic baffles. Door speakers don't have much of that, so the speaker's suspension has to be very firm to keep the cones in one piece. Just a little audio trivia.

Lazarus
 
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