I know that there's a volume adjustment. That's not the point. I'm using it to illustrate that the two sets of outputs are at different levels.

Wrong way around. Line level (i.e. NOT the RCA outputs) requires an external amp. The RCA outputs are not line level but are amplified, and passing that amplified signal through to the truck amp adds noise.

 

ok, i think i made a mistake (google is my friend), mixed ‘line level’ with ‘high level’.
so if i am correct my radio has high level outputs and RCA outputs that are both amplified by the headunit?

just connected the brown iso connector from the car to the radio adapter, then i get a loud hish sound through the speakers.

wouldn’t the sound i am getting with rca cables connected be the same when i connect the brown iso connector straight to radio adapter if both rca and high level are amplified?

 

Again, no. The RCA outputs are amplified. The outputs in the plug block are not. I said this in post #4.
I still don't know what you mean by "high level" outputs.

I'm not sure what you're referring to with the brown ISO connector.

 

With high level i mean the cables coming from the radio where you normally connect your speakers to if there is no amp.

with brown iso i mean B in the picture.
coming straight from the amp I guess.
[img]blob:https://landroverforums.com/30d0fb81-3a2f-4034-9cac-b122e800171d[/img]

as you allready noticed, don’t know much about car audio, appreciate your time

 

I still don't understand. If you have no amp, then you use the amplified outputs. In this case, those would be the RCA outputs. But you shouldn't be connecting the RCA outputs to your amp.
The outputs in the plug block go to the amp from the stock radio, or from this radio. The stock radio doesn't have RCA outputs.

No picture is showing up, sorry. There are tags, but the image isn't found.

 

Did they provide an adapter from the pin-header of the head unit to the brown DIN/ISO connector? I would try that and you could avoid the isolation transformers (which have limitations regarding max signal level and frequency characteristics).

 

When i get back this weekend i’ll make a short movie to make things more clear.
perhaps i’m using the wrong terms for certain connectors.

 

The Rover wiring should plug directly into the Joying head unit. No adapter is necessary. However, some wiring splicing is needed to get the amp to turn on, etc.

 

Then we have different versions i think, it won’t fit in mine. I have this version;

https://www.joyingauto.eu/best-7-sin...ooth-wifi.html

 

I'm sorry, I was incorrect when I said that the Rover plugs will fit directly into the back of the unit. Mine came with a harness, and the Rover plugs fit into that.
I have this unit: https://www.joyingauto.com/joying-ch...head-unit.html
The back of mine looks identical to the photos in this thread: https://landroverforums.com/forum/di...-screen-88717/