A6 BOSE System With Sony headunit Problem

rich dj

2015 A4 Avant 2.0TDI SE Quattro 190 Technik
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I have an A6 Avant with a Bose upgrade and have removed the Audi Bose head unit and replaced it with a Sony CDX DAB 6650 and the connection leads with 4 rca (phono plugs) to plug into the sony pre outs and no speaker outs at all, it all works but you get a very loud click when track skipping or changing audio settings as if the sony is not muted during these fuctions.
Has anybody come across this problem before or any ideas.
ps i am and have been an audio engineer for 20 years so im not clueless.
:keule:
 
No it's normal unfortunately. The Bose amp has a wierd capacitor setup on its input stage to filter electrically noisy processes on the Audi HU. So when an aftermarket HU mutes the RCA's (like any HU should) it discharges the capacitor array and thus the loud pop or click you are experiencing.
The only way round it on the Bose setup is to use the speaker input adapter rather than the RCA input adapter. This plugs into the speaker outs of the HU and uses a hideous hi/lo or line out convertor to take the speaker level back down to pre-out level. Obviously from an SQ perspective it is not recommended but it is the only way to get rid of the popping.
The only other alternative is to replace all the speakers and either wire them up directly to the HU and/or invest in a proper amp. The Bose speakers a re 2ohm impedance so the HU won't like driving them directly.
 
****** nothing is simple.
i dont think i want to go down the speaker to line level adaptor way.
i may have to modify the bose amp if i can get hold of a circiut diagram for it,
so no mp3 or Dab for me yet then.
Anybody help with diagrams?:keule:
 
Sorry you had to find out the hard way (like me).
There was a tech article on AW about removing the capacitors but I can't find it now, but I remember the guy said it wasn't worth it in the end.
Honestly the line level convertor method is surprisingly OK and by far the easiest option, I'd give that a go first before reaching for your soldering iron!
But by far the best method would be to replace the Bose speakers and run them off the HU, the Bose system really doesn't like being interferred with and when you see the "quality" of their paper cone speakers it's amazing it sounds as good as it does, the tweeters they use aren't even Bose they are the same Nokia crap as the non Bose setup.
 
mmm
thinking going on, ok i have replacement mac audio speakers seperates, the high end ones i could put them in the front and drive from the head unit but then i would have to put wires to the door or find the bose amp and connect to the lead there(assuming i can find it first any ideas) or just replace the bose amp with a 2 ohm rated amp x4 outs, the other things i was going to try before doing this was try a couple of ground loop isolators in line to the front and rear outs to take out the dead short of the mute or to add in line a couple of capacitors to do the same thing, any body tried this.
i also spoke to my local in car fitting company and was told that "yes this happens somtimes on Sonys but my Alpine works fine and buy another head unit mate" that did not go down very well as i am very pleased with my Sony unit
so the only thing i could come up with was the Alpines output was capacitor coupled and Sonys was not, i still have to speak to sony technical as yet will do this monday, although i dont hold my breath as they were usless on help getting correct plug for DAB aerial connector, i will also look at the sony service manual when i tap up an old colege for a favor ,
any more help would be greatfull, I will keep you informed,
I DONT GIVE UP VERY EASELY:tocktock:
 
No you'll get the same result with an Alpine HU (the one I used was Alpine), it is the Audi kit that is not in line with the industry standard for muting the pre-outs. Nice try by the dealer though, trying to sell you a new HU.
The only HU that might be more compatible would be a Blaupunkt as they were the original HU's fitted in Audi's and they still use the stupid mini ISO connector for the pre-outs. My DAB unit is a BP but, from previous experience, I'd already decided to rip out all the Audi kit before I started so not sure if it would make a difference.
No idea if a ground loop isolator would help, worth a try.
The Bose amp is in the trunk, so not too difficult to link up the speaker outputs.
 
also tried kenwood HU supossed to have the best ground isolation still the same...

ok so tried ground loop isolators this works no clicks but...
now sounds all over the place front and rear and left and right not all in phase
frequency responce curve on these ground loop isolators is all over the place.
they were cheap ones but this is not the way to go
Next...tried isolating the ground on the phono leads....next

Sounds realy good if you just plug in the phono leads shame about clicks,
now trying a capacitor in line with the signal leg of the phono leads if this does not work then speaker line level convertors from autoleads
let you know how i get on :keule:
 
ok after much messing around popping and such like i placed many different capacitors and found by putting a 15uf capacitor in line with phono plugs no clicks and no apparent loss in sound quality, did not have time to make full adaptor leads up to give road test but i will tomorrow when i pick up some phono plugs and sockets to fit caps in.
Nice simple filter dc to about 40hz ish..
i will give a good test and let you know.

ps another anoying thing is i have to take the face off when the cover on dash goes over...
 
the only thing i forgot to test is the amp rca ground the same as the HU rca ground potential,
i will road test tommorrow and let you know

also i spoke to a car radio fitter and told him my outcome and he said he has a high quality ground loop isolator available at £20 which would do the same job as long as there are no phase differances and a flat responce.
 
Could you help me, I have this problem with my Audi A2. I have tried everything else but it still makes a loud popping sound. Would you be able to send me a list or the bits needed and a wee how-to-do for it please? :thumbs-up:
 
ok will send you details diagrams ect very simple you just need to know how to solder on phono plugs and sockets to screened cables and put capacitors in line in the plugs.
still no road test yet, car away having new radiator fitted now on 3rd day away should be back today sometime.....with any luck
 
rich dj said:
also i spoke to a car radio fitter and told him my outcome and he said he has a high quality ground loop isolator available at £20 which would do the same job as long as there are no phase differances and a flat responce.

Would this fix it as well? Have you got a part number for it if it made by autoleads?
 
just making up leads now in front of pc.
i need 4 phono leads some only need 2 depending on model
i need a web space to send my photos to get on this site any ideas
 
DSC00295.jpg

DSC00296.jpg

DSC00297.jpg

thanks andy
see pictures i will let you know if it works ok tommorrow need to have wife time.
ps capacitors 15uf 16v electrolitic
Tools requied

soldering iron
solder
pair wire cutters
electrical insulation tape
pliers (with an elastic band on the handle to hold plugs so you dont get burnt)
screened cable
4x phono sockets
4x phono plugs (i used angled to get stereo to go in further and to fit in capacitors)
15uf ish capacitors in line pref
 
been busy all weekend may have time tue night sorry
 
ok fitted in tested ok on road as well all ok.
poss slight loss in low bass very small mind you, when i have more time will do comparisons.
Very slight click now when skipping tracks but i mean very slight.
PS i am very fussy when it comes to audio.
I HOPE THIS HELPS PEOPLE SORT THIS STUPID NON STANDARD PROBLEM OUT WITHOUT REMOVING BOSE SET UP.


Now all i have to do is change the factory fit aerial for my DAB replacement type and run additional aerial lead for DAB and we have digital radio and MP3
:rockwoot: :smile: :yes: :arco:
 
If my memory is correct as its been a while, if you are wiring this up for yourself you need 4x phono plugs and 4x phono inline sockets and some screened audio cable ( or 2x pre made leads ie phono extension leads like the link below). shorten (cut cable) to about 6 inches and solder the capacitor inline (in series) with the signal cable like diagram below, the continuous wire is the ground ie the outer screen and the centre wire.
note capacitors should be 16uf electrolytic.
Diagram





https://www.lindy.co.uk/cables-adap...MI-8CDwurT5QIVxbHtCh1OuAQVEAQYASABEgKsB_D_BwE
 
sorry 15uf capacitor