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[MaxV6]

rather than mess up Dave's other thread about speakers any further.


so...    my understanding of our current knowledge.

buried in the bowels of the unit , seems to be an IC package responsible for gain/tone control, and input selection,  spitting out a signal to amplifiers...


however, to make matters more complicated, i understand it seems to do some sort of operational check to be sure there's actually operation of playback hardware being involved.

(specifically on the Multi CD cart input...)

this being the case, it would seem to me to be the obvious answer ,

1) to determine what logic signal is being fed by the cd cart operation, and replicate it,
2) determine the input level being fed to it from the audio source , and build a simple buffer/attenuator circuit to take a line level input and adjust it to suit the required input.
3) cut the circuit traces feeding the IC the audio signal AND logic signal , and connect either side of those  to a switch activated  relay, with sufficient switched poles to accomodate all the signal feeds,  (rather than running the audio all the way out to a switch, and back again, risking noise induction)
4) fit a line level input socket, with a socket switched earth/shield contact to activate the relay ... 


so, when you plug the ipod in using a mini jack stereo lead, the relay flips automatically, and the logic signal and audio signal are switched from the multi CD feed  , to the feed form our dummy signal and iPod .


you could alternatively put a manual switch on so you can select between CD cart and iPod,  but that means finding somewhere to mount such a thing  without looking crap ... 

you could , if you wanted to risk additional noise,  leave out the relay and do it all by feeding out to the switch and back on all circuits, but i personally wouldn't.


so...  who has a unit kicking around in the garage to play with?  working CD cart is probably required...

[zirk]

Been discussed before reed switching the Audio feed on the ribbon cable between CD Changer and HU.

Chris.

[MaxV6]

ahh Missed that one.... 

we chatted about it briefly at the last Wycombe meet,  where someone mentioned, in passing, that the system seemed to check there was anything actually playing in the CD cart.....     

thus my point about the logic circuit , identifying the signal that tells it there is a valid source, and replicating it.

it probably comes in along that ribbon cable also, so it may become slightly simpler to implement the idea...   

got a link?   or the result of the discussion?
....

[zirk]

I did one a while back on a NCDC, used resistor network to lower the MP3 level down a bit then through some capacitors, I/P socket sensor switch through the relays across, like you say down side is CD needs to be on pause from memory.

[Dave DND]

Shouldn`t be too hard to disable the CD player completely rather than put it in pause mode

[Kevin Wood]

I see a couple of possibilities...

1) Figure out the (digital) interface to the CD player part and break into it to convince the head unit that it's playing, then switch the CD signal to an external source.

2) Break into the control to the chip that does the input selection in the main part of the head unit and convince it to select CD when the radio would normally be playing, then switch the CD signal to an external source.

1) is nice and easy because it's all external to the head unit, but the interface is undocumented and potentially complex as, I guess, it also conveys track information for the display and controls track and disk selection information into the CD changer.

2) requires bodgery into the depths of the head unit, but the interface to the chip will be both simple and documented so we have some confidence that we could break into it, insert something as an intermediary between head unit and input selector and define our own behaviour entirely.

[feeutfo]

To my knowledge theres three possibles been discussed on here in the past. Whats possible or economicl i have no idea though.

Michael Grossers web site give an in depth tv input to cid. There is also a link on interupting the ribbon between cd changer and head units within the double din for audio.

3rd one was raised over a curry reguarding the least used function of the head unit. Which i guess would be the cd player function of the nav slot. This would alllow true integration of other sources with proper mute for phone nav traffic master to over lay those mono inputs.

What i really like re the emulator is the hu thinks its a proper radio signal, so all other sourcres mute it for various amouncements or whatever. Well, as you would expect really, point is it gives a feeling of proper integration. If that can be reproduced for a proper hard wired audio source that would be fantastic. (shame about the interference with all the emulators)

[feeutfo]

...and a deathly hush fell about the place.

So where do we go from here? Is any of this realistically possible...?

[Dave DND]

...and a deathly hush fell about the place

[MaxV6]

a deathly hush fell, because i was out.......   



i guess,  since it was my big mouth, and the fact that my existing CD changer is knackered,  it could take my own one apart and see if i can get sense....


i would like to see one with a working CDC purely because it would help identify and analyse  logic and audio signals to have one that will load and play a CD.... 



but i could possibly make some educated guesses by tracing the circuits a bit ....  depending on how much gets hidden in custom packages... 

[feeutfo]

Ok so Max has the audio...

[Dave DND]

Watching this one purely to see what you come up with.

As a quick pointer, the audio is the dead easy bit, but you really ought to find a way to disable the spindle motor / laser / sled motor and loading motors, to prevent any unwanted noises generated from searching for Discs, TOC and data etc.

Regretfully, I am unable to assist any further with this one, and I hope you can understand my reasons why not. Firstly, as a repair centre, I cannot encourage the badly performed internal bodges that the subsequent inexperienced watchers will undoubtedly follow as a result of this, and secondly, unless an external plug and play option can be developed (which the stereo will simply never support) then I`m afraid that it is not commercially viable for me to undertake any further research into this.

Best of luck with it though.

[feeutfo]

As suspected tbh. No worries Dave. Happy Xmas.

[Kevin Wood]

Of course, my CCR2006 has a cassette, the input from which is ermm... not frequently selected these days.

I lent my cassette deck to a relative about 6 or 7 years ago and have only just noticed it's missing.

In fact the whole cassette mechanism could come out and the slot be turned into a dock for my MP3 player, although if I could be confident that an aftermarket head unit with a USB port would take a substantial music collection on a stick and do a competent job of indexing it, I would just swap it.

[Me]

Hmmm, might have a play over Xmas if I get time, seeing as I haven't got a CID yet to play CD70.

My stumbling block will be matching the audio feed in, as thats not an area I excel in (no shit, Sherlock!)