Adding MP3, iPod and USB to standard VW Passat Stereo

Gamma Stereo and CD Changer Passat

I currently have a stock VW stereo system in my ’02 Passat consisting of the Gamma head unit and six disc in-dash CD changer – as pictured below. Works great and as I’m not in to very loud music these days, the sound output is perfectly good enough for me. But what this relatively old-fashioned stereo is lacking is an aux-in socket allowing me to plug in say an iPod or my smart phone. Even a USB input would be nice.

With this sort of input I could do the following:

  • Stream music/audio books from my smartphone, either from the memory card on it or via a service such as Spotify or
  • Play music from an iPod, MP3 player or even something like my iPad
  • Plug in a USB stick or hard drive and play audio from that

So the obvious route to take would be to whip out the old head unit and changer and stick in a nice new one with the described inputs. As I’d then have a double din slot avialable I could even stick in a fancy new unit with a pretty screen! But, having decided some time ago to try and keep my motor fairly stock and the fact I like the Gamma output, I wanted to adapt the existing unit instead. Enter the “Connects2 USB Interface”.

Connects2 USB Interface

Click for larger images

Briefly what this does is connects to the CD input socket on the back of your VW head unit. You then add either a USB input, SD card or anything that works off a 3.5mm jack such as a phone or iPod. The only down side is that you can no longer connect your CD player, so it’s a choice between CDs or these other inputs. I decided I’d prefer the greater flexibility this would give me over CDs.

There are a few models available from Connects2 which work across various cars, so be careful which you buy. My exact model is the CTAVGUSB003. At the time of writing the cheapest I found was £63 from Amazon UK – Connects2 USB Interface CTAVGUSB003 VW Golf/Passat/Beetle/Polo/Lupo


First thing to note is that the one I bought came with two ‘keys’ in it that are used to remove the head unit and also fit the CD changer too.

Passat Stereo Removal Keys

Stereo removal keys

Gamma Stereo and CD Changer Passat
Gamma stereo and CD changer with release points arrowed
The keys are inserted with the hook point up, as in the top one in the picture above. They may need a bit of jiggling about to make them lock on, then the unit should pull right out.At first I just pulled out the head unit and unplugged the connections to it. Later I also removed the changer as it made routing wires much easier.
Gamma Stereo Removed
Gamma stereo removed and disconnected with CD changer out as well.
In the photo above you can see two connectors on the left which are to do with powering the unit and taking the output to the speakers. If I remember rightly the black block is for power and the brown one is for speakers, but don’t quote me on that! On the right you can see the blue CD changer input block and the aerial connector. The blue block should be pushed out of the way into the back of the stereo chassis.Possibly the hardest part of the installation was finding out how to route the Connects2 bundle of cables into the back of the head unit and go somewhere I wanted in the cab. I’d have liked it to come out on the drivers side of the centre console but I could find no easy route through there with what are fairly chunky wires and connectors.What I ended up doing was finding an easier route round the back of the centre console so the USB unit hangs loose in the passenger footwell. More on the positioning of this unit later.So once you have the wires up into the position you want them it’s very easy. First there’s a ground wire that can be attached to a screw thread pole on the back of the head unit. Then you plug the blue connector block into the socket where you removed the existing CD input. Then reattach the aerial, speakers and power block.
Connecting Connects2 Box
Connecting Connects2 box to Gamma head unitNow simply slide back the CD unit if you removed it and then the head unit. Take care to feed the wiring back into the cavity carefully as you slide the head unit in.A couple of notes about the wiring. If you have the same Connects2 box as me there will also be another lead that looks like an earth wire which the instructions didn’t say anything about, so it was just left. Also, in the top picture you can see a black connector block as well as the blue one. This block supposedly can be attached to the back of the CD player, giving it power, though not of course any playability as it’s not connected to the head unit. Pretty pointless really. But on removing my CD changer the connector was in a sealed unit anyway, so this didn’t seem to be an option. As a result this black block was left unused as well.
Connects2 in VW Passat
Connected!This last image shows my Android phone connected to the Connects2 box on a very dirty carpet!Full instructions are given on how to use the unit. The most important part is the use of USB inputs. They have to be formatted a certain way and the files need to go in 6 folders to mimic the CD changer. This then allows you to select which of the six folders you want to play from the head unit, as well as being able to flick through the tracks. But such as the phone or an iPod are just plug and play as  your external device does all the menu stuff.I’ve found the quality of playback to be perfectly good and comparable to CD quality to my ears. I’m no audiophile though and I accept MP3s or streamed music will not be as good as CD quality, but it’s good enough for me.I’ll update this post in the future if I have any issues with the set up, but for now it seems to work very well.

Positioning the box

For now I’ve simply stuffed the box in between the passenger seat and centre console with the wire being tucked under the flap of the centre console. Although the word “stuffed” has been used it’s actually a very secure fit that won’t damage anything and gives me easy access to the inputs from my seat. I could leave it there forever.

However, I have different plans that involve putting out of the way a little better. I also want to add a 3.5mm jack input to one of the dashboard blanks to make connecting my phone neater. All will be revealed in a future post!

Any questions or comments, use the comments box below or send me an email.



  1. Hi Passat Man. I have just purchased my father’s 04 passat estate. It has the gamma tape unit and single cd player. Will I be able to use one of these gadgets on that setup? Also is the little box of tricks and actual mp3 player ie, do you load mp3 tracks on an sd card or usb stick and it plays from that.

    Thanks for your time.

    • Yes you’ll be able to plug this into the back of your Gamma unit but you’ll then lose the use of your CD player. It’s not an MP3 player itself, just a box that tricks your radio into thinking it’s a CD player. You put your MP3s onto a USB stick or SD card and the Gamma unit then plays them. Or you can plug in your smartphone and play music from that. Works great.

  2. I know that this is probably a dead message now, but Passat man has wired this up all wrong, and please don’t follow his instructions. The reason why his Cd player doesn’t work is because he should have it still connected to the head unit. The adaptor blue connector then plugs into the back of the cd player. The extra leads are power and earth that he is talking about, then when you’ve wired those up properly, your ipod or phone will charge too when it is all plugged in, as well as play. There is a lot of misinformation on the web! When this is all done, the gamma head unit will have your ipod, cd, radio and cassette.

    • Thanks for your comment Richard. Nearly 2 years since I did this so I don’t remember the details exactly but it was on the advice of others that I believed the CD player had to be lost in this set up. Will have a look at your method when I get chance.

  3. We only have the head unit; no cd changer. Will we be able to add the adapter unit to the head unit anyway or not?


  4. Hi,
    I have a vw passat 03 and am trying to plug in an ipod but would like to retain the 6CD changer also. Request Richard or Passatman to confirm how this can be done. Essentially I would like to know where the cd connector will plug into as the connector from the box plugs into the cd socket in the radio.

  5. what about on a 2015 passat. I want to be able to use navigation from my phone on the stereo screen as I don’t like the navigation system the car came with.

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