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Hi..my otherwise immaculate and original 2001 Vogue has no sounds or sat nav because the Harman Larson amplifier under the seat has gone on the fritz...it seems a regular fault..but there is no replacements left in the uk from Land Rover stock..and off eBay seems variable!!!
Any experience about mending..working around..some other part that works?
Much appreciated
Thanks in advance
Robert
 

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I have only just joined the forum, (just bought a very sad P38 that needs a fair bit of work), so I am sure that one of the 'regulars' will provide you with some useful advice.

What is the problem and have you checked the basics, (fuse, cable feed, etc), and was it working ok previously and did anything untoward happen before it failed?

If you do find yourself struggling, however, then please let me know as I can usually repair most types of 'in car' entertainment systems - although sometimes I may need track down the schematics if the problem is digital, (as opposed to analogue).

I have all of my 'electrics' out of my RR currently as I am having to give it a deep clean as it has been severely neglected!

Good luck!
 

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2001 Vogue will probably have the DSP system. If it has, then the amp is in the rear compartment with the CD multichanger and not under the seat. This does have a nasty habit of dying because it can. There were 4 levels of audio, low line (2 speakers per door), mid line (4 speakers per door), high line (6 speakers and amps in each door) and the DSP system with just the one amp. Very expensive to replace and so far I know of no-one that has managed to repair one. Does the head unit have a DSP setting? If it does, you've got a problem.
 

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Discussion Starter #4
Thanks....I have now read enough threads to know that this is.....a regular problem....!!!
And it's not a good one.
The car has now been checked in all basic areas ..and the amp has been sent off to an elderly Druid who claims to be able to fix it!!
Worth a punt and if there is any success I will be happy to post the Druids name on the site..as this problem sucks.
I am fully intent on keeping my p38 fully original..air suspended and with its minimum miles one of the best out there...but harman kardon are making it tough....I am amazed there is no work around or after market fix as it seems there are enough sufferers out there...
There seem to be no original amps to buy and some on eBay ..but it's a variable/ slightly unreliable part it seems...and it sure is expensive at £600+
Will report back
Thanks for the replies
Much appreciated
Rob
 

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1995-2002 Range Rover P38A
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2001 Vogue will probably have the DSP system. If it has, then the amp is in the rear compartment with the CD multichanger and not under the seat. This does have a nasty habit of dying because it can. There were 4 levels of audio, low line (2 speakers per door), mid line (4 speakers per door), high line (6 speakers and amps in each door) and the DSP system with just the one amp. Very expensive to replace and so far I know of no-one that has managed to repair one. Does the head unit have a DSP setting? If it does, you've got a problem.
The mid/high/premium (DSP) systems were all 10 speakers systems in total (plus the sub woofer). Rear doors have a low/mid and a mid/hi speaker, whereas the fronts got given low/mid, mid/high, and then a tweeter on the cheater panel that hides the connection for the door mirror.

The tweeters in the front doors have their own filtering capacitor in them and are in parallel to the mid/high speaker.

Mid/High line systems indeed have the amps in the doors - one line level feed in, and then the amp splits the signal into the low/mid and mid/high frequencies, amplifies them, and sends it to the respective speaker(s).

Subwoofer is a separate feed off the head unit and fed directly into the subwoofer amp.

Premium level system (DSP, and generally with the sat nav) as Gilbertd mentions has the amp in the boot - it's behind the trim which is behind the subwoofer/CD stacker. I have a dead one sitting in the garage, which after having a look at it and getting my father, who's an electronics technician to take a look, the general concensus is that the failure on it is somewhere in the DSP chips themselves, which are encased in black resin on the board.

A couple of people have mentioned that they've had ones where it's been a power supply fault, but sadly that seems to be the exception rather than the rule.

If the sat nav is faulty, then you could try disconnecting this, as it has been known to go faulty and constantly send a mute signal to the DSP amplifier (as if it's trying to give instructions, but instead there's silence) which stops the rest of the audio from coming through.

If it's not that, then the only option is to either try and find a replacement amplifier unit, or go aftermarket unfortunately. The DSP amp was missing in my 01 Vogue when I bought it, ans instead of take a change on a £350 amp that may give up at any point, I installed an aftermarket head unit, and rewired slightly to get the audio working as it should. I did a big write up awhile ago about doing the work, building a crossover, and even did a file with all the pinouts, wire colours etc. for the premium/DSP system.

Interestingly enough, the head unit in the Premium/DSP systems is the same part number as the head unit for the standard 'High Line' post 99MY vehicles, not that it would help fix the problem - but was in interesting observation I've made..
 

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I wonder how hard it would be to replace the DSP with a modern device...?
 

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Discussion Starter #8
The amp is the XQK100340 unit that works with the sat nav. My BECM has also been fixed having had a major fault..so slowly all the parts are coming back ...fixed and ready to see what happens when we put it all back together..post Christmas.
I don't want to put a new head unit in if I can help it...
 

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I believe the unit that is widely used in the P38 is XQK100340. This is for vehicles with onboard Navigation aswell. The parts catalogues show XQK100290 as also being fitted to the P38, which I presume is for the version without factory navigation.

I have been wondering recently if it would be possible to put an aftermarket amp in it's place, and it might be something I have a bit of a play around with when I get a chance... as I have a couple of ideas on how it might be possible to do it, whilst retaining the factory head unit.
 

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Had a very brief look at replacment options when a friend contemplated buying a P38 with navigation and high line audio system knowing darn well that if he bought it his problems would become mine in about the time it takes to send and receive an E-Mail. Fortunately I talked him out of that dea!.

I found this thread on another forum :-
http://forum.landrovernet.com/showthread.php/186456-Stereo-replacement-in-2001-RR-Vogue-(last-of-the-P38-shape)-with-HK-upgrade
which seems to suggest that the amplifier control is via TTL level pulse strings. If this is the case it ought to be possible to get all the basic audio functions going on a more modern HK dsp type amplifier with the correct number of speaker drive outputs by simply translating the codes from the P38 head unit into whatever the selected HK amplifier needs. Such transaltion doesn't sound very difficult for a modern, inexpensive, processor board. I would imagine the core function control would be pretty similar, no point in re-inventing the wheel every time, but the extras would be pretty vehicle and trim level specific. Probably very ittle chance of getting the navigation system going via a foreign amplifier without far too much work. Odds are much of the differentiation between modern amplifier models is simple firmware loads so the amplifier mates correctly with the gubbins in the desinged host car. Doing things the sensible way by handshaking and protocol recognition so the basic amplifier block adapts itself to the car so, fundamentally, only the number of outputs matter is not the automotive industry way. Seriously restricts OEM specials only opportunities for picking the customer pocket!

I imagine the communication protocols are out there somewhere so that suspect units can be tested by hooking them up to a computer or test gear. Getting hold of them is probably difficult tho'. The Range Rover system is a fairly early version of automotive dsp based audio systems so its possible that not only the protocols but the whole way of doing the control on a later unit may be completely different with the earlier way of doing things having been abandoned for some engineering or marketing reason. Which would make translation much harder. Not that that would be the only example of the Range Rover way being somewhat different to what has become accepted practice!

Clive

PS A bit more about the control protocol in this thread https://www.landyzone.co.uk/land-rover/need-a-little-harman-kardon-help-please.96772/ looks like someone got as far as making a microcontoller run the codes Inverted RS232 with the wrong voltages! Why do they do this stupid stuff instead of staying standard. It isn't really that much arder to figure out but its a 'kin PIA to work with.
 

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Interesting reads for sure!

I was looking last night into aftermarket amps (non DSP though) and if you wanted to do it in one single amplifier unit, you would need an 8 channel amp... as by default that's what the DSP amp is, as it runs 2 feeds to each door (low/mid and mid/high)... the cost of an 8 channel amp is more than a replacement XQK100340!!

There is other options by using a pair of 4 channel amps - one configured for the front doors and one for the rear doors... the sub could then be fed the line level out of the head unit as it has it's own amp built in (even in the DSP systems).

The fact that the part number for the head unit whether it's a DSP system or not has me wondering that if it doesn't detect a DSP amp connected if it just reverts to a normal head unit as used in the high-line systems.... which in theory you could then connect a couple of aftermarket 4 channel amps (front doors/rear doors - but would have to run the extra 4 wires for rear door feeds from the head unit as the DSP system only uses a Left/Right) up in the area where the DSP unit was and then just run it without the DSP, but as a standard sound system.

I had another brain wave today about another, easier, cheaper way of doing it - but need to look at it a bit more closely and test it first... I've got all the bits at home to test it, so just need the time after christmas to make a couple of wiring looms as a test bed.
 

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Aloha Marty,
I can confirm that if the Head from a "Premium" system such as the one in my 02 is connected to a non DSP amp, like the one I am now running from a Disco, the DSP option simply goes away.
I also tried the head unit from my 2000 which is physically identical, and it did give me the DSP option, but as the stupid amp had failed, it made no noise, so I think they may indeed be the same beast.
Oh, you also lose the rear speakers, and sub woofer with the Disco amp, but as I have had 3 of those DSP turkeys fail so far, I am anxiously awaiting someone's aftermarket fix for DSP
 

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That is brilliant news for what I want to try out...

I have everything at home I need to test my theory, just need a couple of hours in the garage with a soldering iron...

I'll report back (with pictures!) Once I've had a go at making this work....

Aloha Marty,
I can confirm that if the Head from a "Premium" system such as the one in my 02 is connected to a non DSP amp, like the one I am now running from a Disco, the DSP option simply goes away.
I also tried the head unit from my 2000 which is physically identical, and it did give me the DSP option, but as the stupid amp had failed, it made no noise, so I think they may indeed be the same beast.
Oh, you also lose the rear speakers, and sub woofer with the Disco amp, but as I have had 3 of those DSP turkeys fail so far, I am anxiously awaiting someone's aftermarket fix for DSP
 

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There is one for sale on eBay, guy wants £400. I paid 250 when I replaced mine last year, look at the guys breaking them and send messages, most don't advertise them because of the costs they incur, I'm sure your find one if you try
 

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Right,

Well I've been tinkering in the garage this afternoon for a possible solution, and managed to get something working on the bench.

Stereo.jpg

It's a bit frankenstein, and needs a lot of tweaking, but in principal it works.

Basically after my suspicion about the head units from the later 'high line' and the 'premium' sound systems being the same (same part number) and the confirmation from Bolt that they are, that got me thinking into aftermarket systems.

But the problem is that the P38 is a component system in every door - so needs 2 channels of amplification in each door (Low/Mid and Mid/High) or one channel per door and then a passive crossover to split the signal properly between the speakers (which is what I've built into my P38, though I'm using the amplified outputs from the aftermarket head unit). And looking into the price of 8 channel amplifiers (or even 2x 4 channel amps for front/rear doors) it's even more expensive than a replacement DSP amp.

So, my next thought turned to the fact that the high line system effectively has 4x 2 channel amps - one for each door, with in built crossovers to filter the audio signal and send it to the appropriate speaker.

I happened to have 4x door amps from a vehicle we stripped for parts, and all the wiring looms for them - and a pair of ISO connectors. So with a bit of wiring, I've wired the 4x door amps using the connectors from the door looms into the ISO block for the speaker outputs from the head unit. Then paired all the power, ground and remote power on wires.

Hooked it all up to the power supply on the bench, and other than the remote power on not working (need to look into that, I managed to bypass it by putting +12V on the grey/black wire), got it working!!

The fade/balance/bass/treble/subwoofer controls all work as they should and it goes loud! I only have the one mid-high speaker here (the rest are in my door cards at the workshop!) but it all seems to work as it should.

So in theory, if you can get your hands on a set of door amps, and the connectors from the door looms, then you could quite easily make up a plate to bolt the 4x amps to, chop off the DSP amp connector and then wire the 4 amps into the vehicle wiring (Using my document with all the wiring colours!) and then you would in effect have the 'high line' system, but with all 4 amps in the boot, instead of the amps in the doors.

Subwoofer wires could be joined in the wiring loom to keep that working as it should. You would lose the Nav audio (there are ways around that - either wiring it into a mute line on the head unit and switching the drivers door, or adding in an extra speaker like I've done).

The only think you will need to do is run 2 more pairs of wires for the rear left/right doors from the head unit as they aren't in the vehicle wiring - but that it pretty easy, and you can get ISO connector pins to put them into the existing connector.

Once I've figured out why the remote power on wire wasn't working, I'll have a look at doing a bit more testing on it, but first impression is that it seems to work a treat. The head unit I tested it with is from my '00 Vogue which I'll be restoring. It has the XQK100340 amp, but I'm not sure as yet if it works or not. If it doesn't, then I'll be using this setup to replace it.

Thoughts/Questions/Comments?

Marty
 

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Being lucky (I guess?) to own an older P38 with the separate door amps as standard, this is one expensive issue I will avoid, but I really like this plan! They're small but they are great little amps.

The only thing I worry about is the output from the newer head units - is it a balanced signal like the little amps expect? When I tried connecting my door amps up to the line level outputs of an aftermarket head unit, or to one side of the amplified outputs and the other side to ground, it would all sound great... until the engine started. Then I'd get whine from the alternator, and worse, buzzing whenever the headlights were on.

In the end, I built four of the Ray Ambler attenuator circuits and drove them from the amplified outputs properly, and now it sounds awesome. Doesn't help if you're wanting to keep the head unit stock though.
 

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The newer Land Rover head units use the same line level outputs as the earlier Clarion ones did. In fact they use the same door amps up until about 2000 when they started putting the DSP system in - so this idea is mostly around finding a way of keeping the factory head unit for people wanting to keep it stock, but not spend a fortune on a replacement DSP amplifier, only to have it fail again at some point!

I think the reason why some aftermarket systems don't work as well is because the line level on the output of the factory head units is quite high (I believe between 2.5 and 4v) where most head units with line level outputs run somewhere around 1v - which means you have to turn it up loader to get decent level, and thus amplifying any noise aswell. I wouldn't take that bit as gospel as I haven't done extensive research into it yet, but remember reading something awhile back pertaining to the factory head units having a higher-than-normal output level to the door amps.

The attenuators are the best way of wiring in an aftermarket system with door amps already in the vehicle, as Ray has designed them to match the amplified output of a head unit to the input requirement of the door amps.

The way I wired mine with aftermarket system was to make my own crossover system for each door to split the amplified signal from the head unit I'm using - being as I should have had the DSP amp, all the speaker wires and inputs from the head unit terminate in the loadspace, so figured it was easier to use the amp in the aftermarket head unit and then build a passive crossover, which is all wired in where the DSP amp should have been.

Whilst if you are wanting to keep the factory head unit in the DSP systems, this might not be as easy as just swapping the amp out, it should in theory retain all the factory functionality and at a fraction of the cost, as I am sure that standard door amps are fairly cheap. The only tricky bit is getting the connector/wiring out of an old door loom to plug into the amplifier unit itself. I'm going to have a look and see if you can actually get those connectors separately - if you can then it would be easy enough to make up a mini-loom that then gets joined to the vehicle loom and then you just plug the amps in and away you go.

A bit more research needed, yes - but it's a start (and appears to work!)



Being lucky (I guess?) to own an older P38 with the separate door amps as standard, this is one expensive issue I will avoid, but I really like this plan! They're small but they are great little amps.

The only thing I worry about is the output from the newer head units - is it a balanced signal like the little amps expect? When I tried connecting my door amps up to the line level outputs of an aftermarket head unit, or to one side of the amplified outputs and the other side to ground, it would all sound great... until the engine started. Then I'd get whine from the alternator, and worse, buzzing whenever the headlights were on.

In the end, I built four of the Ray Ambler attenuator circuits and drove them from the amplified outputs properly, and now it sounds awesome. Doesn't help if you're wanting to keep the head unit stock though.
 

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Marty, you are a really clever man!
I will be removing the amps from the 00 parts car on my next trip up North!
Very cool solution. and the door amps are way more reliable than the DSP amp.
Thanks!
 

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The newer Land Rover head units use the same line level outputs as the earlier Clarion ones did. In fact they use the same door amps up until about 2000 when they started putting the DSP system in - so this idea is mostly around finding a way of keeping the factory head unit for people wanting to keep it stock, but not spend a fortune on a replacement DSP amplifier, only to have it fail again at some point!
That should be great then :) I'd certainly prefer this route over a questionable replacement DSP amp myself. I've had to replace a couple of door amps on my P38, but they are so cheap over here on eBay, its no big deal.

Last time I looked they ranged from £5-10 posted on eBay, sometimes sold in pairs. Just a case of finding a good source of connectors.
 
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