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Good news folks, I now have a workable procedure for modifying the Video unit to stereo. I've just ordered some components and have an old unit ready to take the new parts. I can then run a few tests to make sure it's all good.

The mod is quite simple requiring only six new parts, but it's a little involved/fiddly in the fitting. The mod utilises Pin 15 if the ribbon connector and is uses Pin 1 of the white connector for our Right channel.

As mentioned in earlier posts the mod basically hijacks an unused part of the Module and replicates the Left channel. The attached schematic shows what we need to add.

Once I have the Modification tested I'll post a PDF of the procedure.
 

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Sorry hasty in my post I forgot to ask... Pete I notice two resistors on your PTV board labelled R4 and R5. Is R4 for the Right channel, and just not connected at one end?
 

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Discussion Starter #123
Sorry hasty in my post I forgot to ask... Pete I notice two resistors on your PTV board labelled R4 and R5. Is R4 for the Right channel, and just not connected at one end?
R4 is right. They're both connected, one's connected on the back-side. The 470s are just mixing the two channels into a mono signal for ribbon pin 6.

You could put your C3 on the back-side of the PTV board, there's a pad there that goes from each channel, to GND. Unless there's a better place to put it inside the lear?

Why the two 220nFs? You could just buy one 470nF. Or is one already installed? I get the feeling that 8K2 will cause it to pickup engine noise, but let's see.
 

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R4 is right. They're both connected, one's connected on the back-side. The 470s are just mixing the two channels into a mono signal for ribbon pin 6.
That's good, I can pick up the right channel here then and link it to pin 15 of the ribbon connector. It's not used on the TV board so it's a convenient pin to use.

You could put your C3 on the back-side of the PTV board, there's a pad there that goes from each channel, to GND. Unless there's a better place to put it inside the lear?
I'll take a look at the possibility.

Can you send a hi-res picture of the back of your board please? It's just so I don't have to keep taking my working TV module apart.

Why the two 220nFs? You could just buy one 470nF. Or is one already installed? I get the feeling that 8K2 will cause it to pickup engine noise, but let's see.
The schematic presented earlier is a direct representation of the part of the circuit on the TV board for the Left channel. I've simply copied it to get our right channel. I too had my concerns to begin with, but that's how Lear or who ever originally designed this unit did it for what ever reason. I'll obviously know better when my parts arrive and the changes have been made and tested.
 

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TV Stereo Mod

Parts arrived this week so I did the stereo mod last night - see photo. I get to test it on Sunday to see if it works.

I did however check for stereo at the BM54 by removing the white plug shown in an earlier post and directly injected audio from an MP3 player. It works well. So a little rewiring to add the stereo channel and that should be it.
 

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Discussion Starter #126 (Edited)
Parts arrived this week so I did the stereo mod last night - see photo. I get to test it on Sunday to see if it works.

I did however check for stereo at the BM54 by removing the white plug shown in an earlier post and directly injected audio from an MP3 player. It works well. So a little rewiring to add the stereo channel and that should be it.
Impressive :clap:

I was looking at your diagram earlier (Audio Mods 1.jpg) and couldn't really understand it, or what LEAR was trying to achieve with it.

The 100R and 1K form a divider, so the signal is reduced to 91%. Then there's a low-pass filter formed by the 8K2 and 10nF together. This looks like a 1942 Hz filter - wtf?

Edit: Just realised the 10nF might need to be 1nF. You'll know if all your treble is gone on one side :)

Double Edit: Or maybe 820R and 10nF are the real values?
 

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Ok it seems when in TV mode without a tuner installed or a valid video signal the module just goes into muted audio.

So in order to test my mods I'll have fit the Digital TV unit from my other module. Right at this moment I don't have the time to do that, packing to go on site. I'll get back to this on my return.
 

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I'd love to get RCA inputs for stereo audio + video (composite) for the tv module.

I know a german has done it already here:
http://www.7-forum.com/forum/4/umbauprojekt-dvd-stereo-pinbelegung-radio-70302.html
http://www.7-forum.com/forum/4/ultimative-loesung-i-pod-dvd-dvb-72577.html

I got a miracast from ebay so I can do airplay from iphone/ipod all I need to do is get video+stereo audio input to the car. I have the BM24+analog tv+h/k audio +navigation with 16:9 installed in the car and also do the PTV digital tv mod to my analog tuner and get stereo tv.

http://www.ebay.com/itm/Car-WiFi-Mi...843?pt=LH_DefaultDomain_0&hash=item541e1412ab

I hope you figure it out how to do the stereo mod to the tv module, it would crack it.
 

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Almost there with my testing... Just going to transfer the upgrade from my current unit to the one modded for stereo.

Fingers crossed it'll work ok. If I have the time I will know by the weekend.

Pete - Can you please confirm, cutting the track shown in the attached picture and feeding that side of R4 to pin 15 that, that will be the Right channel going to pin 15. I hope you follow that.

One thing has occurred to me; if the balance/fader audio settings for the CDC, Radio and Tape have no effect on the TV module the results may not be as good as I hope for. We will see.
 

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Ok quite simply - Anyone want stereo TV? :thanks:

All the modding works well, no engine noise or anything like. Clearly those guys at Lear knew what they were doing. The schematic presented in an earlier post is correct as taken from the left channel. I've copied it and the result is the picture I posted of the modded board.

WARNING - Unfortunately this mod may not work for every one

As soon as I finish the write up and finalise the procedure I'll post a PDF.

Pete - I'll also email you a copy of the procedure so you can add it to your website if you wish.

But for now I think I must show a little smugness for being the first E39 owner to have stereo TV :woot:

Edit - One final test to be sure it's stereo will be to play an audio track Via. USB copied from one of those CD lens cleaners. They separately check the left and right channels. I couldn't do this test earlier because I didn't transfer USB capability to my test module.
 

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Discussion Starter #132
Ok quite simply - Anyone want stereo TV? :thanks:

All the modding works well, no engine noise or anything like. Clearly those guys at Lear knew what they were doing. The schematic presented in an earlier post is correct as taken from the left channel. I've copied it and the result is the picture I posted of the modded board.

WARNING - Unfortunately this mod may not work for every one

As soon as I finish the write up and finalise the procedure I'll post a PDF.

Pete - I'll also email you a copy of the procedure so you can add it to your website if you wish.

But for now I think I must show a little smugness for being the first E39 owner to have stereo TV :woot:

Edit - One final test to be sure it's stereo will be to play an audio track Via. USB copied from one of those CD lens cleaners. They separately check the left and right channels. I couldn't do this test earlier because I didn't transfer USB capability to my test module.
Nice. Are you going to start an installation service, people send you their analog box and you send it back stereo with DVB-T?
 

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Nice. Are you going to start an installation service, people send you their analog box and you send it back stereo with DVB-T?
Yeah that's a good idea, do you fancy working together on that?

I have one guy already in the UK that's wants his upgrading. Maybe you could produce a stereo ready version IE a removable zero ohm link perhaps pre routed to pin 15.

Could do with list of BM54's that will support stereo TV.

I like the look of your simplification for DIY, but no sure what would happen to the audio quality. Would it even be a problem? Could a small PCB be made with the required extra parts for DIY? If I was to mod for folk this wouldn't be needed though.

What do you think?
 

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Discussion Starter #134
Yeah that's a good idea, do you fancy working together on that?

I have one guy already in the UK that's wants his upgrading. Maybe you could produce a stereo ready version IE a removable zero ohm link perhaps pre routed to pin 15.

Could do with list of BM54's that will support stereo TV.

I like the look of your simplification for DIY, but no sure what would happen to the audio quality. Would it even be a problem? Could a small PCB be made with the required extra parts for DIY? If I was to mod for folk this wouldn't be needed though.

What do you think?
Maybe, it's all possible. I can't say I've sold many ptv boards though, demand is minuscule. Respinning the board has to lead to a bit of demand, because it's a fair effort to go to.

I think the missing 100R and 1K will make no difference, just slightly louder. But it would have to be tested.

Originally, I nearly designed a even more complicated board, that could take full control of the rotary encoder, which would make use of the tuner's media player more comfortable for sure. Combine that with stereo and it's not a bad product. It required ripping into the pin 14 & 17 signals though, so I decided it was too complicated for a DIY.

Let's see how your stereo mod shakes out first.
 

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Pete - If you want to come up with a schematic to include the stereo mod, DVB-T etc. I'd be more than happy to design a PCB for it maybe based on the size of my mounting board. That way it would be a add two pillars, cut some tracks almost plug and play installation. To save you some cost as well I could have some PCB's made in the UK and pay you some royalties.

Your right about drumming up support, I mean, how may TV units are in the wild X the number of people actually want this X How many can actually have the stereo mod. The result could be, not that many. I don't think it would make loads of money, but it would make a few very happy BMW owners.

Just to throw in one more idea - I've been thinking of relocating my Pi2 plus PiBus 4 to the video mod for the all in one solution.
 

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Discussion Starter #137
Pete - If you want to come up with a schematic to include the stereo mod, DVB-T etc. I'd be more than happy to design a PCB for it maybe based on the size of my mounting board. That way it would be a add two pillars, cut some tracks almost plug and play installation. To save you some cost as well I could have some PCB's made in the UK and pay you some royalties.

Your right about drumming up support, I mean, how may TV units are in the wild X the number of people actually want this X How many can actually have the stereo mod. The result could be, not that many. I don't think it would make loads of money, but it would make a few very happy BMW owners.

Just to throw in one more idea - I've been thinking of relocating my Pi2 plus PiBus 4 to the video mod for the all in one solution.
I guess you mean this sort of form-factor? That could work, but a lot of people have the tuner with the side-ways soldered down analogue tuner too, there's no holes in that one.

You know you'd be competing with installers like carphonics (in London). You'd have to heavily undercut their price, but then you might be working for peanuts.
 

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I guess you mean this sort of form-factor? That could work, but a lot of people have the tuner with the side-ways soldered down analogue tuner too, there's no holes in that one.
Yes that's the idea. I would need some internal pictures of the other type of TV module to come up with a plan. I recon some support brackets would do the job. Having a physical unit to hand would be better though, I'll have to see if I can acquire one.

I'm working on a jig for drilling the holes accurately, but it's based on your current board so any new board would need either new placement or the same footprint as my setup.

You know you'd be competing with installers like carphonics (in London). You'd have to heavily undercut their price, but then you might be working for peanuts.
I'm not that bothered about making much on this, a few peanuts would do fine. I'd just be satisfied in the knowledge that other fellow BMW owners can have this. After all I love doing stuff like this.

I've only ever charged £10 P.H. and it takes about 2.5 hours to do the stereo mod and fit everything in. I try to work on the principal of providing the best for as little as possible.
 

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Discussion Starter #139
Yes that's the idea. I would need some internal pictures of the other type of TV module to come up with a plan. I recon some support brackets would do the job. Having a physical unit to hand would be better though, I'll have to see if I can acquire one.
I've got one in the post, so can measure it up for you. But these really new models (2004+?) don't have the DIP package TEA chip at all!

I'm working on a jig for drilling the holes accurately, but it's based on your current board so any new board would need either new placement or the same footprint as my setup.
Something like this shape? Want to come up with dimensions and hole placements? No promises, but I might be able to do it some time. But that half cut-off USB cable is a little annoying.
 

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I've got one in the post, so can measure it up for you. But these really new models (2004+?) don't have the DIP package TEA chip at all!
Hum, I'd definitely need one then to see if it's even possible. Some good hi-res pictures and dimensions would be helpful yes. Especially close-ups of the board.

But that half cut-off USB cable is a little annoying.
I agree it would have been nice too use the USB's mounting holes instead of that bracket. The whole lot would need to move about 8mm to the left as you look at the photo or move up a little.

Edit: I plan on changing the position in future.
 
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