I Now Have Aux

[Adam Evans]

I now have AUX in my car

I have interupted the FM signal coming from the tuner and replaced it with my own AUX signal

It works a treat

Simple 5 pin AUX jack and a short length of wire

http://www.maplin.co.uk/pcb-mounted-3.5mm-stereo-socket-1196

No need for relays, no need for CD changer just put your radio onto FM you will hear your radio station and then plug in your AUX cable and it will turn off and onto your IPOD or MP3 player

Sound quality perfect, No hiss

[black400]

Is it on a Ls400 , sat or none sat.

Any instructions planed

[Adam Evans]

I will upload instructions when I get time to sit down and do it.

A little bid fiddly and the only hairy bit that I know people may not like is the point where you have to use a blade to cut the tracks on the PCB

Apart from that it is all straight forward.

Bit of solder and a bit of hot melt glue and you're sorted !!!

All in all it cost me a days messing around (I had to figure it all out)

And £1.79 for the AUX plug

This could be done probably within 2 hours from start to finish

Cheaper than the CD changer hack, neater and better sound quality.

To explain it very simply, I bypass the signal almost just after it has come out of the sky !!!

This is how factoryradioservices do it in USA

[munday]

I will upload instructions when I get time to sit down and do it.

A little bid fiddly and the only hairy bit that I know people may not like is the point where you have to use a blade to cut the tracks on the PCB

Apart from that it is all straight forward.

Bit of solder and a bit of hot melt glue and you're sorted !!!

All in all it cost me a days messing around (I had to figure it all out)

And £1.79 for the AUX plug

This could be done probably within 2 hours from start to finish

Cheaper than the CD changer hack, neater and better sound quality.

To explain it very simply, I bypass the signal almost just after it has come out of the sky !!!

This is how factoryradioservices do it in USA

£10 cheaper, its not neater, its a more involved job with a lot more to go wrong and the sound quality is LOWER than the cd changer method.

Also, you have no opportunity to add in power to charge your device at the same time (which is what I have done)

You pay your money and take your choice :)

[Adam Evans]

I see your point about adding a power socket but I have put the aux right next to the vsc and headlamp washer. This means I can put my iPod into the ashtray and plug it straight into the socket in the ashtray

As for phono being better quality I can't argue with you as it is. But if you are converting 3.5mm out the top of an iPod to phono then surely the quality will be the same

I understand what I have done is quite invasive and not for the faint hearted but it removes the need for a blank CD on repeat

[munday]

I see your point about adding a power socket but I have put the aux right next to the vsc and headlamp washer. This means I can put my iPod into the ashtray and plug it straight into the socket in the ashtray

As for phono being better quality I can't argue with you as it is. But if you are converting 3.5mm out the top of an iPod to phono then surely the quality will be the same

I understand what I have done is quite invasive and not for the faint hearted but it removes the need for a blank CD on repeat

Yeah there isn't a right and wrong way, its just for people to decide what works best for them :)

With the quality issue, I'm talking about comparing the output of the 3.5mm headphone jack to the line-out which is through the normal Iphone connector (like a docking station would have) The line-out is pre internal amp and the highest quality output available. HOWEVER, is the difference noticeable? I'd say not to the average listener. Also, this may be an Iphone specific issue so may not be relevant to a lot of people.

My CD changer is always stocked with cds and just carries on in the background until I decide to listen to them again :)

[Adam Evans]

Fair enough.

I didn"t realise that tapping into the CDplayer was pre-amp. That's why I went for the FM signal in it's purest form which is exactly what you did.

I understand what you have done now.

I am by no means an electronic whizzkid at all. I just got very lucky with this one !!

[jpjsavage]

Would love to see some pictures of what you did if you get the chance to upload some.

[Adam Evans]

Girlfriends mum is staying for the week. But will upload a few photos when I have a bit of time

http://www.aliexpress.com/item/20PC-Lot-3-5MM-StereoJack-Socket-Audio-Connector-PCB-Mount-Free-Shipping-YP03/787109479.html

There is 20 of the correct AUX switches. That is literally how cheap this can be done for

Now you wonder how factoryradioservice make their money !!!

Clever hey

[thatfatbloke]

Girlfriends mum is staying for the week. But will upload a few photos when I have a bit of time

http://www.aliexpress.com/item/20PC-Lot-3-5MM-StereoJack-Socket-Audio-Connector-PCB-Mount-Free-Shipping-YP03/787109479.html

There is 20 of the correct AUX switches. That is literally how cheap this can be done for

Now you wonder how factoryradioservice make their money !!!

Clever hey

Can't wait to see the photo's of your girlfriend's Mum!.

[Cotswold Pete]

I will upload instructions when I get time to sit down and do it.

A little bid fiddly and the only hairy bit that I know people may not like is the point where you have to use a blade to cut the tracks on the PCB

Apart from that it is all straight forward.

Bit of solder and a bit of hot melt glue and you're sorted !!!

All in all it cost me a days messing around (I had to figure it all out)

And £1.79 for the AUX plug

This could be done probably within 2 hours from start to finish

Cheaper than the CD changer hack, neater and better sound quality.

To explain it very simply, I bypass the signal almost just after it has come out of the sky !!!

This is how factoryradioservices do it in USA

There was me saying on earlier post, best not to muck about, it now does seem to make sense.

Am kind of happy with the Cassette adaptor route, sound quality is not that bad, but when parked up and listening to quite music you can hear the cassette trundling away.

Be interested if you do get time to post details, so when i have a spare few hours might do.

As for splitting tracks, if it all goes wrong, reforming with a solder/wire bridge is not a problem, so long as you go gentle when scraping off the pcb coating.

[Adam Evans]

I have a small amount of feedback from the earth signal that I took from the PCB so while the car is in the garage I am going to reroute the earth

I will then upload a step by step about how 5 little wires and a small incision can make all the difference to this car.

I will also test in the morning when I have done it all by playing the BOSE advert tune trough the speakers at full blast as I think that tune is great and has every imaginable frequency and sound in that song:

http://www.youtube.com/watch?v=9Ul42kyGMns

[Cotswold Pete]

I have a small amount of feedback from the earth signal that I took from the PCB so while the car is in the garage I am going to reroute the earth

I will then upload a step by step about how 5 little wires and a small incision can make all the difference to this car.

I will also test in the morning when I have done it all by playing the BOSE advert tune trough the speakers at full blast as I think that tune is great and has every imaginable frequency and sound in that song:

http://www.youtube.com/watch?v=9Ul42kyGMns

When you say 'feedback' do you mean that you have a hum loop, or slight low frequency buzz.

Reason I ask is because with my home stereo where I plug in the iPod via a long phono based lead (with jointed earth) which will be the same as what you have done for the Lexus, I have found that hum/feedback is an issue.

Having thought about it, and played around it seems to be due to the differential impedance between the Left Earth and the RIght Earth points somewhere in the whole sheebang.

So moving earth points outside of the radio may not make any difference.

I would be interested to know if the professional fitters have a balancer behind the jack socket to then impedance match correctly to the head end of the LS stereo, which should eliminate this problem. Impedance matching is key to this type of problem and the iPod will be a low ohm value and the LS internals probably a lot higher.

Just a thought, but would be interested if you do cure by re-routing earths.

[munday]

I have a small amount of feedback from the earth signal that I took from the PCB so while the car is in the garage I am going to reroute the earth

I will then upload a step by step about how 5 little wires and a small incision can make all the difference to this car.

I will also test in the morning when I have done it all by playing the BOSE advert tune trough the speakers at full blast as I think that tune is great and has every imaginable frequency and sound in that song:

http://www.youtube.com/watch?v=9Ul42kyGMns

When you say 'feedback' do you mean that you have a hum loop, or slight low frequency buzz.

Reason I ask is because with my home stereo where I plug in the iPod via a long phono based lead (with jointed earth) which will be the same as what you have done for the Lexus, I have found that hum/feedback is an issue.

Having thought about it, and played around it seems to be due to the differential impedance between the Left Earth and the RIght Earth points somewhere in the whole sheebang.

So moving earth points outside of the radio may not make any difference.

I would be interested to know if the professional fitters have a balancer behind the jack socket to then impedance match correctly to the head end of the LS stereo, which should eliminate this problem. Impedance matching is key to this type of problem and the iPod will be a low ohm value and the LS internals probably a lot higher.

Just a thought, but would be interested if you do cure by re-routing earths.

Maybe you can help with my setup,

I have tapped into the cd changer signal wire IN to the amp. So I use the line-out from my Iphone to go pre amp (using some relays and a switch sop that i can swap between Iphone and CD changer. The cable I am using plugs into the docking connector on the phone, which has 3 RCA connectors (red/white/yellow) of which I am only using the R and L audio lines, and also it has a USB connector spurred off for charging.

Now...when the phone is not charging there is absolutely no interference at all, its clear as could be. When I plug the charger in I get the interference which changes with engine revs and is just generally there all the time.

Do you have any ideas on how to minimise this effect? The lead being used is quite long (1.5m) and for charging I am plugging into a cigarette lighter adapter. From my previous days working in car audio its like a bad earth, or running the signal wires with power wires.

Is hard wiring the charger directly to a 12v and earth likely to help? Will straightening out the connector lead help? Its sometimes worse than others, seems to me that the lower the Battery on the phone the worse it is (drawing more current?)

Thanks :)

[Cotswold Pete]

Adam,

It has been a long time since I did any earth loop poking about.

But I have had similar issues with an old Omega about 7 years ago and sort of gave up (well car blew up before I got around to sorting it all out)

The reason (I think) you only get the problem with the charger is that you have two earths going from your iPOD to the earthing points of the car.

So your lighter will earth somewhere and the earth of the stereo will earth somewhere else.

So the iPod effectively transmits any voltage difference it sees between the two earths.

The best way to cure it (as far as I know) is to have star-earthing so that the lighter and the radio touch an earthing point on the body at the very same place. However you will still have different impedance on earth earth loop, so you may still find that you have annoying enough interference. You would also need to super-supress every device on the LS, which is a nightmare and not really achievable.

So another route I would suggest is you inserted a loop isolator inbetween the iPOd and the jack on the Stereo it would cure it.

Behringer make such a beast (does not require a power source) called HD400. Problem is that most of this gear is used in studios so is all 1/4" based jacks.

So not sure if I have been much help, but you want something that breaks the ground loop, and insert it in the audio feed from iPOD to your switch.

By the way the longer the lead (you say 1.5m) the worse the interference will be, but even if you had a 30cm lead you would still notice a problem on quiet passages.

I have just had a quick look on fleabay and it appears you can get 'audio loop isolators', and not a bad price, mind you not tried but they are such simple devices there is nothing to go wrong.

Best of luck, but any questions, let me know.

I may even try using one for a home stereo situation with a 3metre lead with MP3 into hifi and it hums like a good-un.

Just come across this - http://www.ebay.co.uk/itm/RCA-PHONO-GROUND-LOOP-ISOLATOR-HUM-NOISE-FILTER-CAR-/370174937574?pt=UK_In_Car_Technology&hash=item56302549e6

[munday]

Ah excellent! That's a great post, I now understand the process and what is going on which is all I wanted. With a suggestion of a potential solution thats even better! I'll get one ordered up and let you know the outcome :)

[munday]

Just thought I would update this... The ground loop isolator (as linked in an earlier post) worked a treat :)

[Cotswold Pete]

Just thought I would update this... The ground loop isolator (as linked in an earlier post) worked a treat :)

Excellent, did you install it inside the head unit, or have it outside and neatly hidden away.

I have since found some stand alone transformers that would do the job, and could be mounted inside the unit, but what I am probably going to do is keep using the cassette method on the Lexus for the time being, as i have a thousand other DIY jobs to do around the house first.

[marvs]

I have a small amount of feedback from the earth signal that I took from the PCB so while the car is in the garage I am going to reroute the earth

I will then upload a step by step about how 5 little wires and a small incision can make all the difference to this car.

Hi mate,

I'm very interested to see a step-by-step for this.

On my Pioneer head unit, and some others, there's a test input on the PCB that plays audio when any source is selected, so if you can generate 'silence' from any source then the input on these pins will be heard over the speakers. So I was going to do a basic version of the mod here, but unfortunately I can't because my tape deck never stays in 'Tape' mode (always reverts back to radio), and I don't have a CD changer in my car, so I can't get a silent source.

Therefore your mod seems perfect for me!

In advance of you posting up instructions, can you explain a bit more about where it was that you cut the PCB tracks? I have a '93 car, but hopefully I'll be able to figure it out!

Thanks

[Adam Evans]

Yes sorry I have not had the time to take my head unit back out of my car to take some photos for a step by step

Anyway the easiest way to get silence from your radio will be like this:

Take the board out of your radio and look for the FM tuner

There will be FML and FMR

basically cut through the tracks for these 2 on the board for silence

Don't forget to solder to either side of the inscision that you make with pieces of wire and re-route through a DPDT switch so that as you switch your signal off you can then plug into your AUX points you have found on the board

Someone on the forum might be a bit more switched on than I am and may know how to get it to do it all automatically but unfortunately I don't know how to do this

If you want to upload a few detailed photos of the PCB and the make and model of it maybe I can take a look at the board for you

[marvs]

Thanks for the info. Next time I get a chance to get the radio out I'll have a look for FML and FMR. I guess the best place to solder to either side of the cut will be an existing solder point on the board, rather than trying to solder on the PCB track?

I'm wondering whether a DPST switch would be sufficient? If I'm only using it to make/break the FM signal line to give me 'radio silence' then I'm guessing single throw is fine... Then a separate cable will be connected to the test/aux in line I've (hopefully) found. For info, this test input has three pins, which apparently fit a 'servo cable' like these: link. I could then attach the other end to a 3.5mm plug/socket.

Having said that, if I find the FML & FMR, then in a way I might as well just do your solution as written in the first post, and switch my aux into the FML & FMR lines using the switchable 3.5mm jack like you used, that way it's quite neat in that when the aux is plugged in, it's active, and when it's unplugged it's FM. However having a toggle switch with the separate aux in gives me more flexibility to run a longer aux cable, and potentially have my phone/ipod plugged in even when listening to the radio, then just switched as desired.

Decisions...!

Thanks for the offer of help, too. I'll see how I get on when I next have the head unit out.

[Adam Evans]

Single throw would be fine however there are two channels L and R and if you are to mix them together you would in effect loose the balance in the car and only hear mono.

Yes it is much easier to solder a bit further up the track where the next solder point is (its also neater)

I am going to try and get the head unit back out over the weekend for some photos and a step by step

[marvs]

As far as my (limited) understanding of switches goes, the double pole aspect of the switch means two inputs/channels (so left and right in this case), and the single throw means just open/closed circuit, as opposed to double throw which can be open circuit with up to two different closed circuit connections, so you could have open/signal routed to location A/signal routed to location B...

Does that make sense? And do you agree? By my understanding above, I think a double pole, single throw switch would maintain two channels.

Wiki

[Cotswold Pete]

As far as my (limited) understanding of switches goes, the double pole aspect of the switch means two inputs/channels (so left and right in this case), and the single throw means just open/closed circuit, as opposed to double throw which can be open circuit with up to two different closed circuit connections, so you could have open/signal routed to location A/signal routed to location B...

Does that make sense? And do you agree? By my understanding above, I think a double pole, single throw switch would maintain two channels.

Wiki

This is spot on, and Wiki is right.

So a DPST should do the job you need.

[munday]

Just thought I would update this... The ground loop isolator (as linked in an earlier post) worked a treat :)

Excellent, did you install it inside the head unit, or have it outside and neatly hidden away.

I have since found some stand alone transformers that would do the job, and could be mounted inside the unit, but what I am probably going to do is keep using the cassette method on the Lexus for the time being, as i have a thousand other DIY jobs to do around the house first.

I installed it alongside the AUX input wiring by the amplifier. It all sits hidden nicely under the drivers seat :)