A4 Concert fault - Amplifier fault ??

[v1nny]

Hi all,

Need some advice really..... My Concert stereo comes on, lights up and everything but no sound. Also, I`m getting a shorting sound from the speakers, like 2 wires touching together.

I think the Amp on the stereo has blown. Any ideas ??

Does anyone know if the Amp is built into the Concert stereo (non BOSE) set up. If so, I think I`ll change to a aftermarket unit.

With afterarket units, does anyone know if I will need a DIN to ISO adapter and Areial adapter ??

Any advice will be great.

Thanks all

 

[AndyMac]

If it's non Bose then you have 2 amps. One for the rears (and sub if the cabriolet has one) and the internal HU amp for the fronts, so it is unlikely they've both blown. Bit wierd as "sevosa" on here just posted the same problem with his '03 A3, although he gets sound for a few seconds before it dies and no interference. Hope this isn't an inherent design flaw on newer Audi's taking over from the volume problem with older ones.
If you go aftermarket then you'll need a fascia adapter and antenna amp. The rears are amped but you'd be far better off rewiring them directly to the HU otherwise you'll get a puny volume from them, even with the correct wiring adapter. If you go with a Blaupunkt HU then it's just plug & play, although with any aftermarket unit you'll need to wire the ignition on feed to perm live as newer Audi's don't have an ignition on feed. So manual turn off/on I'm afraid.

 

[v1nny]

Thanks,

From what you say it looks like the HU amp has blown as the interference is from the fronts as far as I can tell.

Does this mean replacing the whole unit or can it be fixed ???

v1nny

 

[AndyMac]

If it's just the internal amp then the rears should still work. It's not worth fixing as you can get a secondhand one on ebay for £60-£70.

 

[Staz]

Andy I found a site (http://www.bluespot.co.uk/install/show_model.asp?id=15) that sells the adaptor cable with RCA connectors for the rear and another with RCA for both. I'm pretty sure thay would solve the problem of low sound. Cheaper than halfords too.

Also Audi's do have a wire that provides 12v when the ignition is turned on. It would mean rewiring the harness adaptor which is easy but I didn't have any of the pins for the ISO connectors so I never bothered.

 

[AndyMac]

Yep that's the adapter I used and no it doesn't solve the problem. To get balanced sound front & rear you have to fade so far to the rear it's untrue.
And no Audi's (2000 models onwards) do not provide an ignition on accessory feed. You can pick up an ignition on feed from the fusebox but this turns the HU off when you turn the engine off. An accessory feed needs to keep the HU on until you pull the keys out. There is nothing on the fusebox that provides this function. Audi HU's use the CANBUS to tell the HU when the keys are out, which is such a good use of a data bus.
Apparently there is one on the actual ignition keyswitch itself, under the steering column but I've yet to pull it all apart to find it. Will get round to it eventually.

 

[Staz]

I'm guessing the 2 yellow wires are the CANBUS yeah? What else do they tell the headunit? Functions from the steering wheel controls?

I'm glad I didn't order that cable then. I still don't understand the problem though. I can't imagine the concert preout voltage is higher than an aftermarket one!

Oh well I'm happy with mine for now

 

[james0808]

Apparently there is one on the actual ignition keyswitch itself, under the steering column but I've yet to pull it all apart to find it. Will get round to it eventually.

There is if i remember rightly its a red wire.

 

[james0808]

The external amp went on mine so i had no rears or sub.I changed the amp for a decent one and put a proper sub in and it sounds really good.Just waiting for a bit of spare time to fit my epic audio controller to it and get some real bass.

 

[james0808]

Forgot to say the short in the wires could be a break in the speaker wires where they go through the rubber to the front door,very common on the A4.

 

[timps]

There is if i remember rightly its a red wire.

Yep small gauge red wire.
Wiring diagram here. http://www.audi-sport.net/vb/showthread.php?t=27732