"Auxiliary In" Hack for HU-6XX series
 

I'm looking to install a Aux Input mini-jack connector to my HU-615 unit via the tape deck PCB. I've seen tons of detailed instructions on how to perform this hack with other head units but not as much info with the HU-6XX series. Has anyone here performed this hack successfully?

I've got a good idea of where I need to solder the L and R leads (to the middle terminal of the two triangular connectors marked Rch/VR701 and Lch/VR702 and have a good idea of where I might be able to get a good ground but some postings out there have suggested that I also need to insert two capacitors on the L and R leads that I solder to filter out the DC noise to the mini-jack plug-in.

I'm looking to confirm that I've got the right L and R connectors identified and also to verify that I need the capacitors...many postings do not refer to this at all and suggest that simply soldering leads to the right connectors will do the trick.

Any comments?

You should read this guide and do exactly the same to get good quality as CD sound.

If you use a previous thread from A.N. Other you will not only risk the chance of blowing your expensive iPod or phone, as they use Electrolytic Capacitors(Black Ones), but the sound quality will be very poor due to the wires for both channels being soldered to the pre-amp side instead of the volume control side of the amp.

The 2uf Suitcase type Capacitors are the correct value not to alter the sound frequencies of the music and the polarity does not have to be observed as the other type has to be and will protect the device used better.

Because the volume control is not like the older type potentiometer where the max. volume comes to a stop it was easy to then just take both channels from the volume switch but these new type pot. switches just turn and turn so one has to trace the circuit back to where the volume can be controlled on the amp. side of the switch.

I have not been inside the HU-615 but the main board must be similar!....if you just use a wire soldered to a sharp point with the said capacitors in line and another wire to earth just prod around the soldered joints without shorting and with the iPod playing and you may find the correct channels. Easiest to do in the car so you will hear left & right channels work.

The best music to play is the Rolling Stones 2000 Light Years From Home as the music is in one channel and the vocals in the other all the way through.

Good Luck

Access to pics in the guide
 

Hi - I don't suppose you have access to the pics that are referenced in the guide by jcwacky...I can't seem to access them at my end. I tried reaching out to JC but apparently I'm too new to directly address an administrator...

Just ran some tests (without capacitors): thumbs down on efforts thus far. Turns out I'm getting good sound but unfortunately it MONO. Interestingly I was getting some major ticking noises coming through and when I disconnected the ground the noise went away.

In reading some of the material above, it appears that I may be taking the signal from the pre-amp vs. amp. I may go back out to car to hunt around for two connections on the main board that provide STEREO output. I'm guessing that those pics could save me some time though....

Not giving up just yet!

Easier said than done...appears that I'm unable to reach any of the main PCB contacts when the tape deck is in.

I appreciate that, but you have to take the unit out of the dash and turn it upside down with the bottom plate off and the wires still plugged in.

Put some clean rag or towel on the gearknob so that the unit will balance on it...Simples!

I have looked at the A.N.Other info and the stereo channels found are not the correct ones for 100% CD quality.

I thought as much but had some difficulty removing the bottom plate. I'll give it another go.

Stay tuned.

Final update
 

See my posts called " Help: HU-615: How to remove bottom panel for access" for a final update. Long story made short: I fried my tape deck and successfully hacked into my cd player. Created a "cd of silence" so that I could play smart phone while activating cd player.

I also disregarded instructions to insert capacitors (regretfully) thinking they were purely a device safety precaution. However now what I've noticed is that if you plug the mini jack in while the stereo is on you here a big thunk noise which I'm guessing might be eliminated with these...thoughts?

On that same note I've seen two capacitors suggested 2nd and 10uf... Any experts want to weigh in?

Also wondering whether I could use two of the capacitors that are on the fried tape deck - there is only one orange "suitcase" device but there are tons of black cylindrical capacitors with a designation of 10uf on them...

As far as i can make out, they need to be the 'suitcase' type, rated as close as you can get to 2uf.

The cylindrical capacitors can hold charge and if there is a problem with the electrics on the car, they can suddenly discharge whatever current they are holding, through the cable and into your phone/ipod!

Well - it appears that I've got a big fat "I told you so" from 960kg coming my way. He had advised that it would not be possible to get good stereo sound if I hacked onto the PCB of the tape deck and similarly it has proven to be the case for the CD player as well.

I get sound but it's at a very low level and after about 10s it begins to distort where clicking is heard with some of the higher frequency audio. On a positive note, I was pleased to note that putting on the capacitors did get rid of the DC thump which was neat to see.

Back to the drawing board. I may opt to hack into the main board at some point soon and will advise on my progress. I would still be interested in hearing from ScoobyDoo555 (I think) who has apparently successfully done the hack for the HU-6XX series. My status as a junior member prevents me from reaching out directly though.