Attaching external audio to 166 ICS

Originally Posted by Gustav_H

I get an alternator wining on my MP3 player when the 12V adapter is connected. Otherwise it's the same good quality as the cd-changer. But it would have been nice to get rid of the wining when charging the MP3-player.

Any suggestions on reducing 12V depending wining?

The main problem is the ground loop....

Try to connect only the +12V to mp3 player.
Since the ground comes from RCA connectors too....

In this case You can hear only the mp3 player's noise...
(Since the small current what is flow through RCA shield can cause a small voltage drop... if this current is constant (case of portable mp3, i think near constant), you cannot hear noise...)

But take care! The RCA shield cannot supply high current!
Just for a small portable mp3 player...

The best solution is a differential driver...
Which can take a reference point from RCA shield, and add the music into this reference.

Analog Devices AD623 - Single Supply, Rail-Rail, Low Cost Instrumentation Amplifier

in the pdf page number 12 / Figure 41/b is the solution for example.

REF connect to RCA shield.
Vout to RCA input

Vin to mp3 player outout.

Vs connect to a filtered and regulated 3-5V supply...


Arnold

If it works it is exactly the thing to put in line with the RCA cable! Must look closer on this one...

I'm not sure if I follow you now Arnold_F.

Should I try to connect he RCA cable ground to the chassis ground of the car?

Otherwise I've found some fairly cheap products that seems to do the trick. They cost about 15 euros.

Originally Posted by Gustav_H

I'm not sure if I follow you now Arnold_F.

Should I try to connect he RCA cable ground to the chassis ground of the car?

Otherwise I've found some fairly cheap products that seems to do the trick. They cost about 15 euros.

NOO!!!!

Connect mp3 to RCA.

But don't connect all the mp3 power line... just the +12V to mp3player (charger)
Don't connect ground to mp3 (charger)!

so the mp3 will get the ground connection through the RCA connector? Is that a good thing???

Ah, I get it.

In other words all ground will go through the RCA cable instead?

How about adding a condensator(not sure if it is the correct term) on the +12V instead? Isn't this a better way to filter out the wining?

Thanks!

Originally Posted by arnoldf

NOO!!!!

Connect mp3 to RCA.

But don't connect all the mp3 power line... just the +12V to mp3player (charger)
Don't connect ground to mp3 (charger)!

what about this? Much cheapness

Alternator Noise Filter ground loop isolator whine rca on eBay, also, Terminals Cabling, In-Car Entertainment GPS, Cars, Parts Vehicles (end time 19-Jun-08 20:00:00 BST)

Or this is probably easier....

GROUND LOOP ISOLATOR GOLD PLATED RCA 201.086 on eBay, also, Terminals Cabling, In-Car Entertainment GPS, Cars, Parts Vehicles (end time 18-Jun-08 21:30:00 BST)

Originally Posted by niallmoran

so the mp3 will get the ground connection through the RCA connector? Is that a good thing???

Yes, right!

Originally Posted by Gustav_H

Ah, I get it.

In other words all ground will go through the RCA cable instead?

How about adding a condensator(not sure if it is the correct term) on the +12V instead? Isn't this a better way to filter out the wining?

Thanks!

I think this is not the source of the problem... but a condensator to +12V all the way a good thing

Originally Posted by niallmoran

what about this? Much cheapness

Alternator Noise Filter ground loop isolator whine rca on eBay, also, Terminals Cabling, In-Car Entertainment GPS, Cars, Parts Vehicles (end time 19-Jun-08 20:00:00 BST)

Or this is probably easier....

GROUND LOOP ISOLATOR GOLD PLATED RCA 201.086 on eBay, also, Terminals Cabling, In-Car Entertainment GPS, Cars, Parts Vehicles (end time 18-Jun-08 21:30:00 BST)

The 2nd looks like okay...
The fisrt only a filter... not a ground loop isolator..

Originally Posted by niallmoran

what about this? Much cheapness

Alternator Noise Filter ground loop isolator whine rca on eBay, also, Terminals Cabling, In-Car Entertainment GPS, Cars, Parts Vehicles (end time 19-Jun-08 20:00:00 BST)

Or this is probably easier....

GROUND LOOP ISOLATOR GOLD PLATED RCA 201.086 on eBay, also, Terminals Cabling, In-Car Entertainment GPS, Cars, Parts Vehicles (end time 18-Jun-08 21:30:00 BST)

Got one of the ground loop isolators off ebay will fit this afternoon and see if it works. Thanks for the link
Nige

let us know how you get on Nige

Sorry mad week last week ended up on the other side of the country will try today and post results

From an iPod connected to the CD changer RCA leads would i get better sound from a lead like this Maplin > iPod to RCA Retractable Cable which connects to the bottom of the iPod. Or from an RCA to 3.5mm jack plug? Or would there be no difference?

Thanks

yeah, will be better with the proper line out connector (like that maplin's one) rather than the headphone out...

Thanks again Niall. Maplins visit on the way home then. I'm going to need a longer one than that though. I might have to get another rca lead to extend it.

fitted the ground loop thingy last night and...........
it completely distorted the sound no good whatsoever. I have contacted the company and will see what they say.

Nige

bad news Nige....

Hursty - this might be a better option for you as it gives power as well:

In Car Radio - IPOD to pair Phono/ RCA Charging Adapter on eBay, also Car Kits, Apple iPod Accessories, MP3 Player Accessories, Consumer Electronics (end time 01-Jul-08 19:20:14 BST)

Ah damn, i purchased the leads from Maplin last night.

If i don't wish to use my CD changer at all, is it possible to plug the iPod directly to the back of the ICS? I'm assuming not.

you need a cd changer emulator to do that, although if you use a phono switcher you can chop the phono lead that runs from the ICS to the cd changer and splice it in there.

Rogier and sanderman and the guys to hunt down if you want an emulator "dongle" - or have a look here if you're good with electronics (over my head thoug!)

GNUnilink for Alfa 166

Forget that. I'm quite happyb running the leads from the boot, to the arm rest under carpets etc. Thanks though.

yeah, that's what i did as well....previously when i was very lazy (not just lazy) i just ran the cable through the ski hatch