rangerovers.pub
The only place for a coil spring is up Zebedee's arse.
Member
Joined: Dec 30 2015
Posts: 987

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: Jan 16 2016
Posts: 109

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: Jan 08 2016
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: Dec 30 2015
Posts: 987

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: Jul 12 2018
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: Mar 22 2016
Posts: 968

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: Dec 30 2015
Posts: 987

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: Jul 12 2018
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: Jul 12 2016
Posts: 573

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: Jul 12 2018
Posts: 3

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

Member
Joined: Jul 12 2016
Posts: 573

https://imgur.com/a/XITzy

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

Member
Joined: Dec 30 2015
Posts: 1192

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: Dec 30 2015
Posts: 987

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.