rangerovers.pub
The only place for a coil spring is up Zebedee's arse
Member
Joined:
Posts: 1234

Hi All,

This is one I posted up on another forum a long time ago now, for when I was working to get a stereo working in my 2001 Vogue which was supposed to have the DSP amplifier and I found it was missing. I have more recently been working on a way to modify the system for vehicle which have had a DSP amp failure (as they are nigh on obsolete) and getting a system working again with the FACTORY head unit. I will do the write-up on here at some point aswell with how I set about installing an aftermarket head unit/navigation system in my '01.

But for the moment, the wiring...

After a lot of searching on the web, and hours in the ETM trying to collate all the information, and find out missing bits, what everything connects to etc - and with a bit of searching on a couple of BMW forums for pinouts in their vehicles that use the same sort of system (sadly not an identical amp though ) I've managed to find out what everything does, including polarities for the speaker connections, head unit connections etc (which the ETM doesn't have)

So, as it was a wet, horrible day here in England, and with tyring to sort through to find come cable colours to wire in my crossover circuits I've built, I figured I'd put it all in one spreadsheet..

And after a few hours work, looking in the ETM again, and collating my pages of notes, I have attached the PDF file to this post. This is the second version of the file, with a bit more information which was clarified regarding the CD-Changer.

Please note also... this is ONLY for the models with the single DSP amplifier in the boot (2000MY On), NOT earlier models with the individual door amps (up to 2000MY).

Marty

P38 Premium Stereo Wiring

Member
Joined:
Posts: 595

I have got an aftermarket Alpine head unit and I fitted a p38 Harmon Kardon bass unit and an Alpine CD changer in the boot. Must be 10 years ago since I fitted it. It uses the Alpine AiNet connectors, so everything speaks to each other. I thought it is about time I updated to DAB and bluetooth but it is not so easy since AiNet has been quietly dropped by Alpine. It means I will loose the CD player if I change the head unit.

Member
Joined:
Posts: 125

That's great, Marty.

Is my old DSP amp any good to you?

I don't think it works, but never tried it.

Postage would be around GBP 15 I'm guessing.

Member
Joined:
Posts: 1234

SpiggyTopes wrote:

That's great, Marty.

Is my old DSP amp any good to you?

I don't think it works, but never tried it.

Postage would be around GBP 15 I'm guessing.

Hi Spiggy,

Yes, I'm happy to take it off your hands if you don't want it anymore... it can go in the parts bin with the other couple I have... One day I might get around to being able to finding out what's wrong and repairing them... one I looked at before with my father (who's an electronics tech) looked like it was the actual DSP chip that had the fault, but I'd be interested to look at a few more and see if it is a common fault...

Drop me an email on p38webshop@gmail.com and let me know your payment details and I'll get the money sent through.

Cheers,
Marty

Member
Joined:
Posts: 3

Hi Marty (sorry to drag up an older post)

I was recently directed to this forum, looks like a really good place to natter.

I’ve just had a frustrating day on the various FB groups after asking for advice. I have this system and the amp appears to be knackered. Radio powers up, sat nav even works .... no sound.

I can’t justify spending 1/4 of the car’s value on a replacement amp, but was toying with taking your diagram to either an auto electrical specialist or audio installer to see if the amp can either be fixed or a replacement fabricated.

Did you ever find a solution to getting the system working ?

Cheers in advance

Chris

Member
Joined:
Posts: 1288

Hi Chris, don’t even waste your time trying to get repaired, no one has managed to repair the dsp amps yet, despite what people say.
Have a search through the posts here, after market is the way to go, better nav for sure, you can connect iPods/phone etc ,
Post,, can Marty help, I think was the name, not long ago it was revived, your get many answers there.

Member
Joined:
Posts: 1234

Hi Chris (well both!)

I have about 5 of the DSP amps here and they are all dead... I've done some fairly extensive probing and it looks like the issue is in one of the DSP chips itself - so they are pretty much just junk.

As a replacement - I do a DSP amp replacement board with 4 standard P38 door amps on it to fit in place of the DSP amp. It requires a bit of wiring in, but it does a decent job of replacing the old amplifier and will work with the factory head unit - or the signal inputs can be either attenuated to use the amplified outputs of an aftermarket head unit, or you can use audio transformers to clean up the normal line level signal from aftermarket head units.

Navigation unit actually has the power to drive a small 1W 8ohm speaker, which for the brief period that I used the factory navigation, worked fine to hear the navigation over the radio. I have been working on ways to include the nav audio into my DSP replacement, but haven't had time to try any of my ideas to see if they work!

I have a bit more info on the DSP amp replacement on my website. I'm actually about to start building another one for a P38 owner up north as he's in the same situation!

Member
Joined:
Posts: 3

Wow.... you’ve been busy with this problem!

Firstly: thank you for the help and advice.

I like your idea to fix the problem, and I assume using the older door amps means that you don’t have the same problem with chips frying?

I’m really keen to keep the car original (even though the sat nav is mince, it works). Depending on what level of work and expertise is involved I’d be interested in your solution (I can solder, but not PCB level stuff).

Member
Joined:
Posts: 967

Hi Chris,

I replaced my dead DSP back in January using Marty's method and did a bit of a write up with photos - I'm at work at the moment so can't access Imgur to get the link .

I'll find it later and post it here.

Member
Joined:
Posts: 3

Amazing.... this is brilliant. I’m willing to have a go!

Member
Joined:
Posts: 967

https://imgur.com/a/XITzy

There you go. Gives an indication of how many wires need to be cut and reconnected etc.

Member
Joined:
Posts: 2191

Holy Carp, Batman. I'd be up for that!! *

*as long as Marty does all the work and I just supply cash and bad jokes....

Member
Joined:
Posts: 1234

I'm in the middle currently of building a DSP amp replacement for a customer. I've got enough bits to assemble another 2 units - but might only have enough wiring to make one more loom at the moment... but the hope is that I will have a couple finished and on the shelf for a change, rather than custom made to order.

Member
avatar
Joined:
Posts: 6129

I recently installed one of Marty's DSP amp replacements and it works superbly however, it got me to thinking. While the door amps are fairly easy to get hold of, the plugs aren't so easy unless you can find a scrap P38 and chop the wiring off. Sooner or later supplies will dry up of both and, while the door amps are still available new, they are ridiculously expensive. So it made me wonder if there is an alternative way of doing it? The amps are just that, amps, but with a built in crossover so have two outputs, one for bass and one for mid/treble. I wasn't able to find a cheap and cheerful amp with crossover but could find amps and crossovers available for not much money at all.

I will stress that I haven't built one of these, and don't have a car with DSP to use for testing, but I can't see any reason why it wouldn't work. If I could lay my hands on a dead DSP amp it would be worth pulling the socket off it to make up a system that could simply be plugged in as a replacement saving an awful lot of time with soldering iron and heat shrink tubing.

I would propose using a couple of TDA7492 based amp units such as https://www.ebay.co.uk/itm/2-x-50W-TDA7492-D-Class-High-Power-Digital-Amplifier-Board-Module/163019456498 feeding into 4 of these https://www.ebay.co.uk/itm/120W-Adjust-Treble-Bass-2-Way-HiFi-Speaker-Frequency-Divider-Crossover-Filter-es/264933727526 or similar. The attenuators may be needed if feeding it with an original head unit but the TDA7492 chip does have variable gain so it might just need the gain turning down. If you are feeding it from an aftermarket head unit with line level outputs, then they won't be needed or if feeding from a speaker output level the amps won't be needed, just the crossovers. If using amps, there is a 12V supply (that originally powered the DSP amp) and a turn on signal from the head unit available at the DSP amp connector so with the addition of a relay the amps would only be powered when the head unit was switched on.

I intended doing a complete write up for someone on RR.net but after the owners removed all the useful information on there I didn't feel inclined to start building it up again. So I've sent the following to the OP by PM and are publishing it here instead. This applies to a situation where the head unit is also being replaced with an aftermarket one so only deals with speakers and crossovers, not the amps, but if it was to be installed as a replacement for the DSP and retaining the OE head unit, then a pair of amps would need to be added before the crossovers.

enter image description here

If you are going to install an aftermarket head unit, you won’t need to replace the DSP amp with separate ones, you just need to link the wiring through at the DSP amp plug. Feeds from the radio all went to the DSP amp and the wiring to the speakers comes from there.

Your aftermarket head unit will have connections for the following:
Permanent power – connect to Purple wire on Pin 4 of C0098 (Grey 8 way connector)
Ignition switched power – connect to White/Pink on Pin 7 of C0098
Illumination – Connect to Red/White on Pin 6 on C0098
Ground – Connect to Black on Pin 8 of C0098
Turn on signal (often marked as for an electric aerial) - Connect to Grey/Black on C0098 (only needed if you intend installing amps)

It will also have the following outputs:
Left Front +ve and –ve – Connect to Yellow and Yellow/Black on pins 5 and 6 on C0092 (Brown 8 way connector)
Right Front +ve and –ve – Connect to Red and Red/Black on pins 3 and 4 on C0092
Left Rear and Right Rear – There will be no wires for the rear feeds at the radio as this was taken care of in the DSP amp. You will need to run two new pairs of wires from here to the DSP amp location.
Subwoofer +ve and –ve – Connect to Orange and Orange/Black on pins 1 and 4 of C0921 (small 6 way connector with only 4 ways used).

Use the diagram above to ensure you get the correct wires on the plug that went onto the DSP amp. With the exception of pin 26 which is the main ground, pins coloured black on the diagram are ones that aren't needed. Although the numbering seems strange, the wires are arranged in pairs just not necessarily on the same row, hence pins 38 and 30 (for example) are next to each other. The back of this plug can be removed so you can cut the wires as close as possible to the plug giving you maximum length to play with and ensure you have the correct wires. I suggest cutting and connecting one pair at a time and not chopping the lot off then getting very confused.

At the DSP amp end you need to connect the wires from the front through to the speakers. Ideally this needs to be done via 2 way crossovers (four, one for each channel) to retain the sound quality.

Left Front – Connect the Yellow and Yellow/Black on pins 38 and 30 to the I/P of the crossover, the low frequency output of the crossover to the Green/Yellow and Yellow/Green wires from pins 4 and 3, connect the mid/high frequency output of the crossover to the White/Yellow and Yellow/White on pins 33 and 34.

Right Front - Connect the Red and Red/Black on pins 9 and 17 to the I/P of the crossover, the low frequency output of the crossover to the Green/Black and Black/Green wires from pins 25 and 24, connect the mid/high frequency output of the crossover to the White/Black and Black/White on pins 11 and 12.

Left Rear – Connect the pair of wires you have run to the back of the car from the Left Rear output of the Head Unit to the I/P of the crossover, the low frequency output of the crossover to the Green/Blue and Blue/Green from pins 2 and 1, connect the mid/high frequency output of the crossover to the Blue/White and White/Blue on pins 31 and 32.

Right Rear – Connect the pair of wires you have run to the back of the car from the Right Rear output of the Head Unit to the I/P of the crossover, the low frequency output of the crossover to the Green/Red and Red/Green from pins 23 and 22, connect the mid/high frequency output of the crossover to the White/Red and Red/White on pins 13 and 21.

If you choose not to use crossovers and are quite happy with a ‘muddy’ sound quality, then simply parallel the Low and mid/high frequency feeds to the speakers.

The sub output from the radio simply loops through the DSP amp so the input and output need connecting together. Connect the Orange and Orange/Black on pins 39 and 40 to a matching pair of Orange and Orange/Black wires on pins 6 and 14 which go to the sub.

You will be left with a few spare wires that aren’t being used. These are for power to the amp (two supplies, one on a Purple wire and the other on a Brown wire), the switch on signal, Navigation mute, Navigation voice input, Road speed signal (for the speed dependant volume adjustment), Ground, DSP data, Phone Mute and Phone audio input (yes, despite numerous people butchering the wiring to add phone kits, there was a simple plug in loom available from LR that integrated a mobile phone with the existing system). All these spare wires should be insulated so they don’t short out against ground or each other.

I’ve gone through this at least 3 times now to make sure I’ve got it correct and haven’t got my +ve and –ve feeds crossed (which, again, will result in poor sound quality), but check through the diagram and legend above just to see if you can see any errors.

Member
Joined:
Posts: 4

Hi All

I wonder if this is the place to put this ???

As a COMPLETE NEWBIE to Range Rovers, (Always shied away from them, tooo many bad reports about bad electrics and suspension)

My girlfriend LOVES THEM! . . . So . .. . we got one . . . lovely drive, I have to say!

The CD Player has decided to give me ""NO CD"" when I press the button for the auto CD Changer (located in the boot)

On another forum, (Yank) they advise me to get a new CD Player !?? . . .

Another one suggesed blowing air through the thing, (THAT idea has NOT worked) . . . There is a cheapy Genuine Range Rover CD Player on eBay . .. .

Any thoughts of trying to repair my one, or purchase the cheapie on eBay ??

Thanks

Geoff

Member
avatar
Joined:
Posts: 6129

The CD changer is just a standard CD changer. Ealier cars with the Clarion head unit need the matching Clarion CD changer, later ones with the Alpine head unit, need an Alpine one. It doesn't have to be the genuine Land Rover one, as long as it is the correct make.

If you have the Clarion, adding a line in is dead easy so instead of playing CDs you can stream audio from a phone, tablet or MP3 player (see http://www.stockholmviews.com/p38/index.html#clarion) or go one step further and add Bluetooth too. Not so easy with the Alpine but the Grom BT3 works well too (https://www.gromaudio.co.uk/products/bluetooth-hands-free-and-a2dp-car-kits/bmw-mini-rover-bluetooth-integration-kit-678.html).

Member
Joined:
Posts: 296

SENKOP wrote:

Hi All

I wonder if this is the place to put this ???
As a COMPLETE NEWBIE to Range Rovers, (Always shied away from them, tooo many bad reports about bad electrics and suspension)
My girlfriend LOVES THEM! . . . So . .. . we got one . . . lovely drive, I have to say!
The CD Player has decided to give me ""NO CD"" when I press the button for the auto CD Changer (located in the boot)
On another forum, (Yank) they advise me to get a new CD Player !?? . . .
Another one suggesed blowing air through the thing, (THAT idea has NOT worked) . . . There is a cheapy Genuine Range Rover CD Player on eBay . .. .
Any thoughts of trying to repair my one, or purchase the cheapie on eBay ??

Thanks
Geoff

Or just put cd cleaner disc in every so often 🤗